Stepped ignition timing corrector. Improvement of the octane corrector

"Ignition timing variator - octane corrector" designed to correct the ignition timing in cars with a mechanical ignition system (distributor) equipped with LPG, the variator also performs the functions of an octane corrector when the engine is running on gasoline.

1. Increases power.

2. Saves fuel.

3. Prevents exhaust valves from overheating and burning.

4. Allows you to fine-tune the ignition timing, dynamically, when the car is moving using the ANDROID application.

5. Monitors engine parameters, displaying them in real time on the ANDROID application screen.

Photos of appearance and android applications.

The essence of the problem, when switching from gasoline to gas, is that gas burns longer than gasoline, which means that an earlier ignition timing is needed, i.e. the mixture must be ignited earlier. Otherwise, the mixture will burn out in the exhaust manifold, overheating the exhaust valves, damaging them; the valve seats are also damaged. At the same time, naturally, power decreases, the engine does not work in mode, hence the increased consumption.

So, there are the following serious problems when switching to gas without an appropriate correction of the IOC (Ignition Advance Angle).

1. Damage from overheating of exhaust valves, seats.

2. Reduced engine power.

3. Increased consumption.

4. Possible pops.

This variator was developed specifically for engines with a mechanical ignition system (distributor). These are mainly carbureted engines, but distributor-ignited injectors are also common.

On engines with a mechanical ignition system, when switching to gas, many try to solve the problem by twisting the distributor to the plus, but they get new, even more serious problems. Firstly, the problem is not solved by twisting the distributor, because. the range of change of the advance angle is very small during this torsion, the advance angle is simply not enough. When working on gas, the lead angle in some engine operating modes can reach +20 degrees, naturally, the distributor cannot do this. Secondly, when the distributor is twisted, the ignition timing (IOC) shifts over the entire range by the same value, while for gas a certain curve is needed for the correct correction of the IOC. And thirdly, an even more serious problem appears: when switching back to gasoline, with the distributor turned all the way to the plus, strong detonation will occur in places, and the engine can be severely damaged. There are also problems when running on gasoline. The quality of gasoline at different gas stations of the same brand can vary greatly, and an appropriate correction of the ignition timing (octane correction) is necessary.

How does this UOZ variator work?.

When the engine switches to gas, the variator increases the ignition advance angle (IDO) depending on the engine speed along the optimal curve for a certain type of gas, i.e. the mixture will ignite earlier, thereby eliminating all the negative factors listed above. The schedule according to which this correction will be carried out is preset for methane and propane, but it is also possible to adjust this schedule manually, by experience, to fine-tune your engine. It is possible to set a delay for turning on the UOZ correction when switching from gasoline to gas, up to 10 seconds. This may be necessary if your HBO makes a smooth transition from gasoline to gas, respectively, and the UOZ correction for gas should be turned on after a certain time.

When the engine switches to gasoline, the variator works as an octane corrector, and the UOS can be adjusted separately for different engine operating modes: starting, idling, operating mode, because the loads in the distributor do not provide optimal UOZ in different modes (mechanically, this is simply impossible). For example, when starting the engine, it is better to increase the UOZ, the start will be much easier, and setting +10 degrees at idle raises idle speed at the same gas consumption, which means you can turn the quality screw back and save gasoline at idle.

The variator also has additional functions for more comfortable use in a car. It monitors a number of vehicle parameters and transmits them to the application screen in real time.

The main functions of the device.

When running on gas:

1. Changing the ignition timing from 0 to +20 degrees, at speeds of 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000.

2. Rebuilding the graph of the ignition timing for methane by pressing the METHANE button.

3. Rebuilding the graph of the ignition timing for propane by pressing the PROPANE button. 4. Setting the delay time for turning on the UOZ correction when switching from gasoline to gas, from 0 to 10 seconds.

When running on petrol:

5. Ignition advance change +-10 degrees in the speed range from 200 to 500 rpm. (engine starting).

6. Ignition advance change +-10 degrees within 1000 rpm. (idling). 7. Changing the ignition timing + -10 degrees in the speed range from 1500 rpm. and above (working mode).

8. Real-time display of parameters: real ignition timing, type of fuel, engine speed, on-board network voltage, on both tabs GAS, PETROL in digital form.

9. Real-time display of parameters: real UOZ, type of fuel, engine speed, on-board network voltage, in digital form, as well as with visualization in the form of panel instruments on the DATA tab.

Description of the android application.

You can manage all the parameters of the variator using the android application in real time. This is very convenient, because all necessary settings can be made from the passenger compartment while the car is moving (dynamically). This allows you to fine-tune the variator specifically for your car!

All adjustment parameters are saved in the variator, so there is no connection to the android device. They forgot the phone - it's okay, all the parameters are stored in the non-volatile memory of the variator, the engine will work on these last changes. Moreover, as a rule, setting these parameters is necessary only for the first time after installing the variator. In general, adjustment is not a mandatory procedure, the variator immediately works on a pre-installed map (a graph of the advance angle versus rpm). However, manual adjustment is implemented for finer tuning. Any parameter is stored in non-volatile memory after 20 seconds after its change.

Regardless of what type of fuel the engine is currently running on, two main tabs of the GAS/PETROL application are available.

The GAS tab shows a graph in the form of an equalizer, by moving its knobs you can set a certain lead angle for certain revolutions. There are two preset buttons: PROPANE / METHANE, when you click on them, the graph is rebuilt to the optimal one, for a certain type of gas.

There are three sliders on the PETROL tab. This is an adjustment of the UOZ for gasoline in different engine operating modes. STARTING mode - this slider controls the UOS when starting the engine (revs up to 500rpm).

IDLE mode - UOZ adjustment in the region of 1000 rpm.

OPERATING MODE - UOZ adjustment above 1500 rpm.

The GAS/PETROL tabs switch automatically when switching from one type of fuel to another, while both tabs can be switched manually. The parameter groups for gas and petrol are available for editing regardless of the type of fuel the engine is currently running on.

The variator also has additional functions for more comfortable use in the car. It monitors and transmits the following parameters to the application screen in real time: engine speed, the actual lead angle that the controller is currently outputting, the type of fuel (gas / gasoline) and the voltage of the on-board network.

All these parameters are visible on both tabs GAS, PETROL in digital form, as well as on the DATA tab, separate for these parameters, where the parameters are displayed not only in digital form, but also in the form of instrument panel for more visual visualization.

Connecting the variator via Bluetooth with an android application.

Run the application, press the “CONNECT” button, available Bluetooth devices will appear in the window. The variator has the name "HC-06". If this name is not in the list of available devices, then press the “search” button, after the device with the name HC-06 is found, pair it with it (password 1234). After that, the connection will be established. Pairing can also be done using the android platform, after pairing, simply open the application and select a device with the name HC-06 from the list.

Safety.

Since the parameters are changed in real time, errors when transmitting or receiving incorrect parameters could lead to very undesirable consequences while the car is moving. For this, a special, secure exchange protocol was developed that provides transmission with confirmation. This measure ensures the reliability of receiving and transmitting parameters between the android device and the CVT, completely eliminating the possibility of errors during transmission and receiving erroneous parameters in the engine control process.

Variator connection.

The variator is connected very simply! Plug it into the hall sensor gap using standard connectors, no wires need to be cut, just snap two connectors, and connect the orange wire to power the gas valve.

In order for the variator to monitor and transmit the voltage of the on-board network to the application screen, the red wire must be connected to + 12V of your car, through a fuse. If this is not done, everything will work normally, only instead of the on-board network, “0” will be displayed on the application screen

• #1

  Interesting stuff! Indeed, he himself noticed that you can’t wind a lot with a distributor, anyway, the car is stupid. So it will be necessary to try your variator. Actually the question itself, I realized that when driving, from the passenger compartment it is possible to adjust the gas curve according to the sensations of the car, but are such adjustments on the go not dangerous for the engine?

• #2

  Such manipulations with the advance angle while driving are absolutely not dangerous, you also press the gas while driving and the ignition timing also changes, and this is normal. This is just an angle correction, and the fact that it changes while driving does not pose any danger to the engine. The permissible range of angle change is not critical, and the engine will not stall, it is just desirable to correct the angle not very sharply, but more or less smoothly.

• #3

  We are a company that has a product for automotive electronics - Ignition Timing Variator - Octane Corrector.
  Can I contact me to make you a specific offer.-
  [email protected]
  Bulgariq
  www.runeltech.com

• #4

  Good afternoon Rumen. You can contact me by writing to me through the "Contact" tab on this site. http://site/%D0%BA%D0%BE%D0%BD%D1%82%D0%B0%D0%BA%D1%82/

• #5

  CVT was purchased and installed on the Audi 100 C4 2.0.
  Since after installing the HBO-4, in principle, everything was pleasing, the smoothness of the engine, the softness of the work, but the car was kind of cottony and there were jolts when pedaling lightly (release the trigger and after rolling push the trigger light). The 2.0 engine is already a little weak for such a mass of body, and then there is also the loss of dynamics.
  After adjusting the angles through this variator, everything returned to normal, the dynamics on the bottoms became no worse than on gasoline. Of course, the standard angles laid in the variator had to be corrected according to a personal "butt meter", but it is already clear that each engine requires its own nuances. The "blue tooth" also pleases, no cables, no laptops to carry, connect at any time, correct, test and change the battle.

• #6

  How can I contact you regarding the purchase of a UOZ-octane corrector variator with a trailer and an injector. Engine 1g-fe.

• #7

  People, tell me they are "alive"? or how? My address; [email protected]

• #8

  How to purchase your UOZ variator? my mail [email protected]

• #9

  I would like to purchase a variator. I have a dual-circuit ignition vaz2107. my address [email protected] or viber.0953866558.

• #10

  Interested in Angle Variator, how to buy? , mail [email protected]

• #11

  Hello.
  How to buy an octane corrector?
  [email protected]
  

• #12

  Interesting Angle Variator. mail [email protected]

• #13

  Can I still buy? Or is the topic dead? If not, then
  [email protected]

• #14

  I want to buy a device.
  +380952005192

• #15

  Is it possible to buy a UOZ variator? Kazakhstan.

• #16

  They don't respond to requests at all

• #17

  You can buy a variator www.60-2.ru, including in Kazakhstan.

When operating a car, sometimes, depending on the quality of the fuel being refueled, it becomes necessary to correct the ignition timing.

Octane corrector device:

1. frame;
2. octane corrector;
3. screw

How to adjust the ignition timing?

The ignition timing is corrected by the octane corrector 2 of the ignition distributor, which allows you to reduce or increase the ignition timing. Signs "+" (advance) and "-" (delay) printed on the scale of the octane corrector indicate the direction of its rotation.

Adjust the ignition timing on a warm engine. Before adjusting, mark the position of the middle notch of the octane corrector on the cylinder block.

Detonation Angle Correction

When driving on a level road in direct gear at a speed of 50 km/h, depress the accelerator pedal sharply. If this causes a slight and short-term detonation, then the ignition timing is set correctly. In case of strong detonation (early ignition), loosen nut 3 and turn housing 1 by 0.5–1 division clockwise (by "-").

If there is no knocking (late ignition), turn housing 1 by 0.5–1 divisions counterclockwise (to "+").

Fixing the adjusted position

After adjustment, tighten nut 3 and check again for correct ignition timing while driving.

The economic, power and operational parameters of a car engine largely depend on the correct setting of the ignition timing. The factory setting of the ignition timing is not suitable for all cases, and therefore it has to be corrected, finding a more accurate value in the zone between the appearance of detonation and a noticeable decrease in engine power.

It is known that with a deviation from the optimal ignition timing by 10 degrees, fuel consumption can increase by 10%. It is often necessary to significantly change the initial ignition timing depending on the octane number of gasoline, the composition of the combustible mixture and actual road conditions. The disadvantage of centrifugal and vacuum regulators used on cars is the impossibility of adjusting the ignition timing from the driver's seat while driving. The device described below allows this adjustment.

From devices similar in purpose, the electronic corrector is distinguished by the simplicity of the circuit and a wide range of remote setting of the initial ignition timing. The corrector works together with centrifugal and vacuum regulators. It is protected from the influence of the bounce of the breaker contacts and from interference from the vehicle's on-board network. In addition to correcting the ignition timing, the device allows you to measure the speed of the engine crankshaft. The described one differs from the digital corrector in that it provides smooth adjustment of the correction angle, contains fewer parts and is somewhat easier to manufacture.

Main technical characteristics:
Supply voltage. At 6...17
Current consumption when the engine is not running. A,
with closed breaker contacts 0.18
with open breaker contacts 0.04
The frequency of the trigger pulses. Hz... 3.3...200
Mounting initial angle of OZ on the distributor, deg .... "20
Limits of remote correction of the OZ angle. deg........ 13...17
Delay pulse duration, ms:
largest .... 100
smallest .... 0.1
Switching output pulse duration, ms........ 2.3
The maximum value of the output switching current. A. . . 0.22

The operation of the engine at the setting angles specified by the corrector is possible if the impulse from the chopper is delayed for a time:
T3=(Fr-Fk)/6n=(Fr-Fk)/180*Fn,
where Фр, Фк - the initial ignition timing set by the distributor and the corrector, respectively; n - frequency of rotation of the crankshaft; Fn=n/30 sparking frequency.

Figure 1 shows on a logarithmic scale the dependences of the duration of the spark delay time on the crankshaft speed calculated for various values ​​of the initial ignition timing set by the corrector. This graph is convenient to use when setting up and calibrating the device.

Fig.2

On fig. 2 shows the characteristics and limits for changing the current value of the ignition timing depending on the engine crankshaft speed. Curve 1 is shown for comparison and illustrates this dependence for a centrifugal regulator with a set initial ignition advance angle of 20 degrees. Curves 2, 3, 4 - resulting. They were obtained during the joint operation of a centrifugal regulator and an electronic corrector at installation angles of 17, 0 and -13 degrees.

The corrector (Fig. 3) consists of a trigger node on a transistor VT1, two waiting multivibrators on transistors VT2, VT3 and VT4, VT5 and an output key on a transistor VT6. The first multivibrator generates a spark delay pulse, and the second controls the transistor switch.

Assume that in the initial state the breaker contacts are closed, then the transistor VT1 of the start node is closed. The forming capacitor C5 in the first multivibrator is charged with current through the emitter junction of the transistor VT2, resistors R11, R12 and the transistor VT3 (the charging time of the capacitor C5 can be controlled by the resistor R12). Forming capacitor C8 of the second multivibrator will also be charged. Since the transistors VT4 and VT5 are open, VT6 will also be open and will close the "Interrupter" output of the ignition unit through resistor R23 to the case.

When the contacts of the breaker open, the transistor VT1 opens, and VT2 and VT3 close. Forming capacitor C5 begins to recharge through the circuit R7R8R14VD5R13. The parameters of this circuit are chosen so that the capacitor is recharged much faster than its charging. The recharge rate is controlled by resistor R8.

When the voltage across capacitor C5 reaches the level at which transistor VT2 opens, the multivibrator returns to its original state. The more often the breaker contacts open, the lower the voltage is charged to the capacitor C5 and the shorter the duration of the pulse generated by the first multivibrator will be. This achieved an inversely proportional relationship between the spark delay time and the engine speed.

The decay of the pulse generated by the first multivibrator through the capacitor C7 starts the second multivibrator. It generates a pulse with a duration of about 2.3 ms. This pulse closes the VT6 transistor switch and disconnects the "Interrupter" clamp from the body and thereby simulates the opening of the breaker contacts, but with a delay of time t, determined by the duration of the pulse generated by the first multivibrator.

The HL1 LED informs about the passage of the pulse from the sensor-interrupter through the electronic corrector to the ignition unit. Resistor R23 protects the VT6 transistor if its collector is accidentally connected to the positive wire of the car's on-board network.

The protection of the device from the bounce of the breaker contacts is provided by the capacitor C1, which creates a time delay (about 1 ms) for closing the transistor VT1 after the breaker contacts are closed. Diodes VD1 and VD2 prevent the discharge of the capacitor C) through the interrupter and compensate for the voltage drop that occurs on the conductor connecting the engine to the car body when the starter is turned on, which increases the reliability of the electronic corrector during engine start. The device protects the VD8C9 circuit, VD6, VD7 zener diodes, R2, R6, R15 resistors and capacitors C2, S3, Sat from interference arising from the on-board network.

The crankshaft speed is measured by the VD9VD10R25R26PA1 circuit. The scale of this tachometer is linear, since the voltage pulses on the collector of the transistor VT5 have a constant duration and amplitude provided by the zener diode V07. Diodes VD9, VD10 eliminate the effect of residual voltage on transistors VT5, VT6 on the tachometer readings. The rotational speed is counted on the scale of the PA1 milliammeter with a current of full deflection of the arrow 1 ... 3 mA.

The corrector used capacitors K73-17 - C1, C8, C9; K53-14-C2, C5; K10-7 - SZ, C6; KLS - C4. C7. Resistor R8 - SDR-12a, R12 - SDR-6, R23 - is composed of two MLT-0.125 resistors with a resistance of 10 ohms. Diodes KD102B, KD209A can be replaced with any of the series KD209 or KD105; KD521A - on KD522. KD503, KD102, KD103, D223 - with any letter index. Zener diodes KS168A, D818E can be replaced with others with the appropriate stabilization voltage. Transistors KT315G can be replaced with KT315B, KT315V, KT342A, KT342B; KT361 G - on KT361B, KT361V, KT203B, KT203G; KT815V - on KT608A, KT608B.

The details of the device are mounted on a printed circuit board made of foil fiberglass with a thickness of 1 mm. A drawing of a printed circuit board and the location of parts on it are shown in fig. 4.

Fig.4

To set up the device, a power supply with a voltage of 12 ... 14 V is required, designed for a load current of 250 ... 300 mA. A resistor with a resistance of 150 ... 300 Ohms with a power dissipation of 1-2 W is connected between the conductor from the resistor R23 and the positive terminal of the power source for the time of tuning. A breaker simulator is connected to the input of the device - an electromagnetic relay. Use an open pair of contacts; one of them is connected to the common point of the resistors R1, R2, and the second to the common wire. The relay winding is connected to a generator that switches the relay at a frequency of 50 Hz. In the absence of a generator, the relays can be powered from a step-down transformer connected to the network.

After turning on the device, check the voltage at the zener diode VD6 - it should be 6.8 V. If the corrector is assembled correctly, then the HL1 LED should light up when the breaker simulator is running.

In parallel with the transistor VT3, a DC voltmeter with a scale of 2 ... 5 Vs is connected with a current of full deflection of the arrow of not more than 100 μA. The resistor slider R8 is brought to the extreme right position. When the chopper simulator is running, a voltage of 1.45 V is set on the voltmeter scale with a trimming resistor R12. At this voltage, the duration of the delay pulse should be 3.7 ms, and the initial angle 03 is equal to -13 degrees. In the middle position of the slider of the resistor R8, the voltmeter should show a voltage of 1 V, which corresponds to a zero initial angle of the OZ and in the extreme left 0.39 V - 17 degrees (see table).

The most simple (but not quite accurate) corrector can be set up as follows. The slider of the resistor R12 is set to the middle position, and the slider of the resistor R8 is turned by a third of the full angle of rotation from the position of the minimum resistance. By turning the housing of the ignition distributor by 10 degrees in the direction of earlier ignition (against the movement of the shaft), the engine is started and the resistor R12 is used to achieve stable idling. To calibrate the scale of the initial angle regulator, an automobile stroboscope is required.

The tachometer is calibrated by adjusting the resistor R26 (with a triggering pulse frequency of 50 Hz, the microammeter needle should show 1500 min "). If the tachometer is not needed, its elements can not be mounted.

To connect the corrector, a five-pin socket (ONTs-VG-4-5 / 16-r) is installed in a place convenient for the driver, to the contacts of which the conductors from the on-board network, breaker, ignition unit, housing and tachometer (if provided) are connected. The corrector, mounted in a casing, is installed in the passenger compartment, for example, near the ignition switch.

The corrector can be used in conjunction with the electronic ignition unit described in. It can work with other trinistor ignition systems with both pulsed and continuous energy storage on the capacitor. At the same time, as a rule, no modifications are required in the ignition blocks associated with the installation of the corrector.

Literature:
1. Fuel economy. Ed. E.. P. Seregina. - M.: Voennmat.
2. Sinelnikov A. Device EK-1. - Behind the wheel. 1987, no. 1, p. thirty.
3. E. Kondratiev. Ignition timing regulator. - Radio, 1981, No. 11. p. 13-15.
4. Moiseevich A. Electronics against detonation. Behind the wheel, 198B No. 8. p. 26.
5. Biryukov A. Digital octane corrector. - Radio. 1987, no. 10, p. 34-37.
6. Bespalov V. Block of electronic ignition. - Radio. 1987, No. 1, p. 25-27.

List of radio elements

Y. Arkhipov

It is known that the optimally set and reproducible dependence of the ignition timing (OS) in the entire range of conditions and operating modes of the internal combustion engine contributes not only to the most efficient combustion of the working mixture, obtaining maximum engine power and throttle response, increasing its efficiency and reducing toxicity, but also achieving uniformity of work (smooth running) and, as a result, an increase in engine life. In modern practice in the automotive industry, the OZ angle on a particular type of engine is most often made dependent on the following five factors:

octane characteristics of gasoline;
engine crankshaft speed N;
rarefaction in the throttle space of the carburetor, which characterizes the load on the engine;
coolant temperature;
humidity of the air entering the carburetor.

The sequence of their enumeration fully reflects the history of improving ignition systems, and in fact - the degree of influence of these factors on the quality level of engine building. The exception is the last two, which should be swapped. However, taking into account the influence of air humidity still remains a technically intractable task and, therefore, is rarely implemented in practice. The reason is the lack of compact cheap sensors with acceptable characteristics. And the fact that this is desirable is noted every time by an attentive motorist, comparing the “soft” rhythmic operation of the engine in wet weather with the “ringing” uneven - in dry weather.

These factors can be divided into rapidly changing, depending on the mode of operation of the engine (speed and load) and relatively long-term (all others). Therefore, the first of them should be taken into account automatically, which is carried out separately on domestic automobile engines by a centrifugal automatic machine and a vacuum corrector (if any). The latter, if they are not taken into account automatically, due to their inertia, could also be adjusted manually, especially since it is necessary to correct (shift or modify) the entire curve “OZ angle - crankshaft speed”, i.e. f (N) (in In the text, this is the letter phi (N) note Krylov P.V), which is a characteristic of a centrifugal machine.

The overwhelming majority of motorists, recalling this machine, usually ask two questions: what should be the most advantageous control curve for “his” engine copy and to what extent it corresponds to the actually reproduced one. The answer to the first question is given in, on p. 39: “Each type of engine has its own optimal characteristics for changing the ignition timing with speed and load. When using the fuel recommended by the instruction, they practically do not change from one copy to another. Further on p. 40: "... the characteristic of centrifugal governors of most modern engines at a low crankshaft speed lies significantly below the optimum, which naturally entails a loss of power in this mode (sometimes up to 5 ... 10%)".

To confirm this, p. 42 shows three graphs of detonation dependencies and one - maximum power, related to the VAZ engine, which are presented in fig. 1 unchanged.

Rice. 1. Adjusting the ignition timing along the detonation boundary (using the VAZ engine as an example)

As in the original, in Fig. 1 also shows the "factory" characteristic of the ignition distributor type 30.3706 at the initial (setting) angle of the OZ fn = 7 °. As you can see, it is far from the graph 2 closest to it, not only and not so much at N - 500 ... 1500 rpm, but in the range of 2700 ... 4700, i.e. just in the region of the most commonly used speed, corresponding to the same maximum torque. Theoretically, such a mismatch can be largely corrected if the bracket of the second (hard) spring of the centrifugal machine is bent so that it starts working after N = 3300 rpm, thereby extending the operating interval of the first (weak) spring to the same limit and, in addition, replace the second spring with a stiffer one. However, even after that, in the area of ​​2700 ... 3200 rpm, the deviation will be about 5 °, and at low speeds it remains the same.

In practice, although this is a simple, but very time-consuming job, which requires at least a stroboscope and a specially made sector with angular markings. But the main thing is that during the adjustment process, due to the instability of the centrifugal machine, random errors when opening the breaker contacts, and due to inaccurate setting of the speed, you can make a mistake up to ± 5 ... 7 °. Within the same limits, the strobe mark also flickers (at N more than 2500 rpm), characterizing the spread of reproducible OZ angles. At the service station, at best, they will set the “factory” curve (or say that they have set it) with factory tolerance limits.

The described digital OZ angle controller (TsifRUOZ) is a PROM-based synthesizer of the function f(N) and an auxiliary corrector. The regulator is designed to be used instead of a centrifugal (mechanical) machine in conjunction with an automated electronic ignition unit (ABEZ) or any other electronic ignition system, provided that its control input is coordinated with the synthesizer output in phase, voltage amplitude and pulse power.

The error in the representation of the initial characteristics of the OZ is determined by the stepwise digitization of their values, and at N more than 615 rpm does not exceed ±0.3°. At a lower rotational speed, the OZ angle is set equal to the initial one. The maximum number of characteristics recorded in the memory and the accuracy of their approximation are limited only by the capacity of the PROM. The applied IC K556RT7 (or K556RT18) allows you to record two or four characteristics with deviations from the original ones up to ±0.3° and ±0.5°, respectively, and for example, IC K556RT5 - only one and with the largest of these deviations. It is possible to “switch” the recorded dependencies manually according to the octane characteristics of the used gasoline grades and smoothly shift each of them along the engine speed axis, and with the help of a corrector, in addition, adjust the slope and change the initial angle of the OZ.

The synthesizer is designed to work primarily with a non-contact ignition signal sensor. Moreover, for the programs recorded in the memory, it is assumed that at each half-turn of the crankshaft (four-stroke four-cylinder engine) the sensor gives a signal/pause ratio of 135°/45°. If it is different, then you will have to change the PROM programming table. The choice of this ratio is due only to a higher accuracy of approximation of the initial characteristics. The synthesizer can also be used with an interrupter, for which the controller includes a control signal converter to the signal/pause type 135°/45°. At the same time, it also performs the functions of the mentioned corrector.

The schematic diagram of the regulator is shown in fig. 2, and time diagrams of work - in fig. 3.

The synthesizer includes a clock pulse generator (TI) of constant frequency, a pulse counter, the number of which characterizes the period of rotation of the crankshaft (T) (otherwise, the period counter (SchT), the pulse counter for generating the control signal (otherwise the control counter (CCH), PROM, a comparison device and a trigger for fixing the coincidence of codes, a pulse generator for resetting counters, an output stage for generating an ignition signal.In addition, the synthesizer has an indicator of its proper operation and a pulsed power supply device for the PROM IC.The corrector (aka signal converter) consists of an RS-trigger, differential type integrator and Schmitt trigger on operational amplifiers (op amps), their bipolar power source.

The TI generator is assembled on two logic elements DD7.3 and DD7.4 (the first one is switched on by a repeater, the second - by an inverter) according to a circuit with high frequency thermal stability - 0.05 ... 0.07% per ° С. To improve it by another 2-3 times, a thermocompensating capacitor was used as C2. And since the actual temperature range of the controller operation does not exceed 60°, the maximum deviation of the frequency of the TI generator causes a shift in the angle 03 of no more than 0.5°. Moreover, with increasing frequency, the angle decreases, which should be recognized as a favorable circumstance, since the regulator installed, for example, under the hood will respond to an increase in engine temperature in the desired direction. The duration of the TI is determined by the timing chain R7C2 and is equal to 1.8 ... 2.2 μs, and the frequency is determined by the circuit R5R6R8C2, which, depending on the details of recording the characteristics in memory, can be equal to 28 or 14 kHz (respectively, R5 is 39 k and 75 k ). The exact value of the frequency is set by the resistor R6, and its operational change in order to shift the characteristics along the axis is carried out by the resistor R8.

The period duration counter is 10 bits and the control counter is 8 bits. The first is made on ICs DD1 and DD2.1, and the second - on ICs DD3. The output code of the period counter is the PROM address code (DD4).

The applied IC (2048X8 res.) makes it possible to record, as noted, two or four OZ characteristics. Shown in fig. Option 2 corresponds to two characteristics that can be switched using SA1 by applying a log to the input 21 of the most significant bit of the address. "0" or "1". In the case of recording four characteristics, it is also necessary to switch the output of the 22-10th bit of the address, disconnecting it from the period counter.

The comparison device consists of eight XOR elements - DD5 and DD6. The outputs of the EPROM and SCU are connected to their inputs in bit pairs, and the diode assembly VD3 - VD10 with a load resistor R9 is connected to the outputs. A trigger for fixing the coincidence of codes is connected to the output of the assembly, which is used as a counter DD2.2. It controls the operation of the output stage, assembled on the element DD7.2 and the transistor VT1. Diode VD12 and resistor R12 provide reliable closing of the transistor at log. "0" at the output of DD7.2, which corresponds to a voltage of 0.3 ... 0.5 V. When the synthesizer is working together with ABEZ, they are not needed, but the emitter of the transistor should be connected to point Upit 2. The need for a trigger for fixing the coincidence of codes is due the task of obtaining on the collector VT1 the same signal shape as on the collector VT5 ABEZ. Without it, the code match signal would exist only during the TI, since the PROM has a pulsed power supply.

With the beginning of a positive pulse in the signal of the contactless sensor (BD) F, i.e., the measuring interval, which corresponds to the 135° sector of the crankshaft rotation (Fig. 3, a), using the differentiating circuit R1C1 and the Schmitt trigger on the element DD7. 1, a positive pulse with a duration of 3 ... 5 μs is formed to reset all counters, including DD2.2.
At the same time, the log level is set at the inputs of CN DD3 (pins 1 and 9). "1", excluding the effect of TI on the CP inputs (pins 2 and 10). With the help of the inverted sensor signal F (Fig. 3,b), the log level is set at the inputs CN DD1 and DD2.1. "0", allowing the counting of pulses (Fig., 3, d). By the way, both sensor signals, direct and inverted, are the voltages on the collectors, respectively, VT5 and VT4 ABEZ. The triggers of the counters used in the synthesizer are switched at the moments of the decline of positive pulses at the SR inputs. The first TI, which occurs simultaneously with the zeroing pulse (Fig. 3, c), is not taken into account by the counter, since the R input is predominant.

At the end of the measuring interval, the logic levels at the CN inputs are reversed, the CCT stops, and the CCU starts counting clock pulses. When its output code becomes the same as the output code of the PROM, all outputs of the comparison circuit will be set to "0", and a positive pulse drop will occur on the resistor R9 (Fig. 3, e), which will translate the low output bit DD2.2 to "1" ( Fig. 3, f). After that, a log will be set at the output of the DD7.2 element. "0" (Fig. 3, g), since both of its inputs have a log. "1", the transistor VT1 will close and a positive pulse will appear on the collector, which is an ignition signal (Fig. 3, h). When working with ABEZ, capacitor C6 must be connected to the output of the synthesizer, disconnecting it from the collector VT5 (ABEZ). It is most convenient to bring it to the connector pin with two sockets: connect the VT5 ABEZ collector to one, and the synthesizer VT1 collector to the other.

With the help of diodes VD1, VD11, positive potentials are applied to the GTI, causing a breakdown in generation (stopping the GTI).

This is necessary when the meter overflows, which is possible at low speeds, as well as when the comparison device is triggered. In the first case, if the GTI had not been stopped, after the overflow of the counter, the PROM address code, and with it the output code, would begin to repeat. After the end of the measuring interval, the operation of the control system would inevitably lead to a false, i.e., not corresponding to the control law, operation of the comparison circuit and the output stage. Moreover, the value of the OZ angle could turn out to be anything, from the initial to the maximum, but it should be exactly equal to the initial one. To exclude this, the positive pulse at pin 5 of DD2.1 that occurs when the SCHT overflows, forcibly sets the log level at pin 8 of DD7.3 (“output 1”) of the GTI. "1". At the same time, the log level remains at pin 11 DD2.2. "0" and the output stage is triggered by the decline of a positive pulse in the inverted signal of the BD, which means that the reproducible angle 03 is only equal to the initial fn, which is determined by the setting of the BD. Such a technique (GTI stop) is preferable to all others, because with the beginning of each new measuring interval, the generation of clock pulses begins with the same phase. This advantage is also important in the second case, especially at rotational speeds of 2500...3200 rpm, for which two addresses that differ by one correspond to the maximum change in the OC angle.

The synthesizer uses a pulsed power supply of the PROM, because with the existing large duty cycle of the TI (15 ... 40), it is simpler in circuitry and design, more economical and more profitable in terms of the thermal regime of the IC. The device is a two-stage power amplifier based on transistors VT2, VT3. Control signals are supplied to it from the "output 2" of the GTI (pin 11 DD7.4), which are out of phase with the TI. Since the counter switching delay (100...200 ns) is much longer than the PROM exit time after switching on to the operating mode (30...60 ns), in fact it works with address codes as well as with a constant supply voltage, which eliminates false operation of the device comparisons by transient codes at the output of the PROM.

The synthesizer has a failure indicator, which includes VT4, VT5, R17 - R20, C3 and the HL1 LED. Transistor VT4 and integrating circuit R18C3 make up the peak detector, and VT5 is a power amplifier. Controlled signals are positive pulses at the output of DD2.2. With a decrease in their duty cycle, which corresponds to an increase in the frequency of rotation and (or) the angle of OZ, the brightness of the convergence of the LED increases.

To compile a programming table according to those shown in fig. 1 charts can be used in many ways. It turned out to be the most rational to replace the characteristics of the OP with sets of polynomials of low order, the easiest way - with quadratic parabolas of the form

Therefore, it should be the minimum of all the characteristics of the OZ recorded in the memory at N=Nmin (in the synthesizer fn=6°). Examples and the procedure for recording the results of calculations according to formulas (1) - (4) for a number of characteristic points of the dependence f (N), compiled from graphs 2 (for AI-93 gasoline) and 4, are given in Table. 1. It also contains the corresponding data in the case of writing f (N) with a nine-bit PROM address.

In table. 1:

The shift of the graph f(N) is shown in fig. 4.

As you can see, when the frequency of the GTI changes, the type of the graph also changes, but the prevailing trend is a shift. By the way, the modification turns out to be favorable: when the characteristic of the OZ is shifted to the right (with increasing frequency), the steepness of its detonation of graph 2 becomes less, and when it is shifted to the left, it is greater. The upper part (chart 4) remains virtually unchanged.

When the synthesizer works with a proximity sensor, there is no practical need for other adjustments. Having 2-4 "switchable" dependences f(N) and the possibility of changing the GTI frequency by ±7 ... 5%, it is possible to cover the entire area of ​​detonation characteristics corresponding to AI-98 (95), AI-93 gasoline grades with the above accuracy , A-76 and their surrogates. The EPROM chosen when compiling the programming table and once set the initial angle of the OZ during the operation of the engine, obviously, will not need to be adjusted, because usually DBs do not contain wear parts that affect fnl. The maximum accuracy of the synthesizer (with a 10-bit PROM address) can only be realized with a sensor that is controlled directly from the crankshaft (structurally, most often from the flywheel). The traditional sensor drive from the ignition distributor shaft introduces a random error in the OC angle up to 0.5 ... 1 °. In this case, it would be rational to limit ourselves to a 9-bit address, which will reduce the required amount of memory or double the number of recorded OZ characteristics.

The synthesizer can also be used with a conventional interrupter if it is supplemented with a control signal converter of the required form (see Fig. 3, a). The schematic diagram and timing diagrams of the operation of such a device are shown in fig. 5 and 6.

It functions like this.

When the breaker contacts are opened (Fig. 6, a), the Q-output of the RS-flip-flop, assembled on logical elements DD8.1 and DD8.2, is set to the level "1" (Fig. 6, b). The voltage corresponding to it acts on the non-inverting input of the integrator DA1.1, and on the inverting one - "0" from the Q-output of this trigger. The output voltage of the integrator is

Therefore, after switching the RS-trigger, the voltage at the input of the Schmitt trigger - the non-inverting input of the op-amp DA1.2 - will increase linearly (Fig. 6, c). When it reaches the trigger switching threshold, a positive voltage drop will appear on the cathode of the VD4 diode, i.e., the log level. "1", which will switch the RS flip-flop to the opposite state. After that, Uout1 will begin to decrease linearly until the next opening of the breaker contacts or to the minimum possible voltage at the output of the op-amp DA1.1, if the opening frequency corresponds to 400 ... 500 rpm. At the beginning of the descending branch of the graph Uout1, the Schmitt trigger will return to its original state. Thus, at its output, when switching, short positive pulses are formed (Fig. 6, d), the duration of which is determined by the ratio of the resistances of the resistors R8, R9 and the value of t1. With the values ​​indicated in the diagram, it is approximately 0.5 ms, and the width of the hysteresis loop of the Schmitt trigger is about 0.3 V. The trigger threshold is equal to the voltage at the zener diode VD3, and the thermal stability of the threshold is due to the total TKN of this zener diode and the diode VD4.

Obviously, the duration of the positive pulse at the Q-output of the RS flip-flop corresponds to the measurement interval in the contactless sensor signal, and the pause corresponds to the control interval. The ratio between them within the stability of the device and the limits of the output voltage of the integrator does not depend on the frequency of opening the chopper. With the help of resistor R3, it can be set equal to 135°/45° according to the program recorded in the PROM. It is characteristic that a decrease (or increase) in this ratio is equivalent to an increase (or decrease) in the initial angle of the OZ with a simultaneous slight change in the steepness of the φ(N) dependence, as follows from formula (4).

If, for example, the signal/pause ratio is made equal to 130°/50°, then the programmed dependence will be reproduced by the synthesizer as f(N) with an initial angle of not 6°, but 11° and an increased steepness, as in the case of a decrease in the GTI frequency by (135 ° - 130°) / 135° = 3.7%, because the PROM address code will decrease by the same amount. If the signal/pause ratio is greater than the norm, let's say 140°/40°, then everything will move in the other direction. Compared to the example above, for a 10% increase in frequency, to which the graphs in Fig. 4, here the change in slope is hardly noticeable.

For example, at the break point of the characteristic (at 2820 rpm), the OZ angle will decrease not by 4.2 °, which was the maximum value, but only by 1.5 °, while due to a decrease in the initial angle, the entire characteristic will shift by 5 °. This feature of the described signal converter creates a beneficial opportunity electronically (with the help of resistor R3) to correct the initial angle of the OZ in the case of synthesizer operation from a chopper by at least ±5 ... 7 ° with a practically unchanged form of dependence f(N).

In addition to correcting the angle of the OZ, this device also allows you to adjust the slope of the characteristics of the OZ, but only in the direction of decreasing the steepness. For this, the integrating circuit R2C1 is designed, which provides a time delay for switching the RS flip-flop, independent of the value of N, relative to the moment the breaker contacts open. The delay time range is td=0...0.7*R2*C1, and the delay angle fz = 180°tdN/30. With the indicated values ​​of R2, C1, this is up to 1.1° at 800 rpm, up to 3.9° at 2820 rpm and up to 8.2° at 6000 rpm. The possibility of introducing fz together with the correction of fn with a slight change in the slope of the characteristics of the OZ leads to the conclusion that when working with a chopper, it is preferable to set the initial angle of less than 6 ° by turning the ignition distributor, rather than vice versa. Then the upward correction of fn with the help of R3 will lead to an increase in the steepness of the characteristic, and it can be reduced by introducing a delay. As unnecessary, the time delay circuit can be removed by connecting R1 directly to terminal 6 of element DD8.2

An inevitable unpleasant consequence of the use of an op-amp is the need for a bipolar power source. An example of a diagram of such an autonomous device is shown in fig. 7.

Rice. 8. Schematic diagram of a common power supply for an automated electronic ignition unit (ABEZ) and a digital ignition timing controller

On the elements DD8.3, DD8.4, an RC pulse generator of the meander type with a frequency of 20 ... 40 kHz is assembled. It controls transistor switches VT1, VT2, to the emitters of which two-link voltage multipliers are connected for each polarity. Voltage stabilization is carried out using resistors R16, R17 and zener diodes VD9, VD10.

If TsifRUOZ is supposed to be used in conjunction with ABEZ, then it is advisable to make a common power supply according to the scheme shown in Fig. 8.

In parentheses are the designations of the elements available in the ABEZ, and the underlined ones are in the synthesizer. Its advantages are based on the overcompensated stabilization of the output voltages of the blocking generator, which also includes the transformer T1 (ABEZ) with additional windings V and V1. Thanks to the overcompensation, it is not even necessary to stabilize the voltage of U4 and U5. All specified voltage ratings are provided by changing the voltage of the car's on-board network Ea from 6 to 18 V (in reality, this range is even wider in both directions).

It is characteristic that when Ea is less than 8 ... 9 V, the current in the coils L1 and (L3) flows through the diode VD25 (VD24 is closed), since the amplitude of the pulses (reverse blocking generator) on the winding V is higher than this value, and at a larger voltage Ea - through the diode VD24 (VD25 is closed). Along the way, the VD24 diode cuts off negative polarity interference voltage pulses that are possible in the on-board network. When using a common power supply in ABEZ, you can remove the VD21 diode and the R38 resistor by connecting the VT12 emitter to Upit 2 (+0.7 V). In addition, it is desirable to connect the common points of the resistors R11 with R12 and the emitter VT5 with the synthesizer capacitor C3 to Upit1. In this case, the consumption currents will be as follows:

in the Upit1 (+ 7.7 V) circuit less than 10 mA (without taking into account the current consumption of the synthesizer LED, which can be 0 ... 12 mA);

in the Upit2 circuit (+0.7 V) less than 3 mA;

in the U3 circuit (+ 6.2 V) less than 10 mA;

through the U4(-15 V) circuit up to 5 mA;

through the circuit U5 (+15 V) 13 ... 15 mA.

The digital regulator is structurally integrated with an automated electronic ignition unit. All its details are placed on a separate printed circuit board (Fig. 9)

Made of foil fiberglass with a thickness of 1.5 mm, having the same dimensions as the boards of the mentioned block. On the carrier plate of the block housing, it is installed together with two other boards with an edge and is also fastened with screws using angle brackets. Chip cases are glued to the board through fabric spacers about 1 mm thick with leads outward, i.e. from the board surface. Connections are made with PEL-1 0.12 wire directly “from leg to leg”, and diodes with their wire leads are also used as connecting elements. Foil conductors are used only for power buses and ground. The corresponding conclusions of the IC are soldered to them by means of racks made of wire with a diameter of 0.5 ... 0.7 mm. For other parts - transistors, diodes, capacitors and resistors - printed wiring is normal.

Load resistors PROM (DD4) Rn1-Rn8 (15 k each) are installed on the side of the foil. To isolate from it, pieces of drawing paper were used, the leads of the resistors were passed in pairs into four holes with a diameter of 1.5 mm, which were drilled between the DD2 and DD4 cases. If pin 9 of the IC DD2.2 is connected to pin 10 of DD7, then the comparison of the output codes of the SChU and PROM and the operation of DD2.2 will be gated by clock pulses.

Capacitors C1 - C3, C5 any type K10-7V, KLS, KM. All resistors are MLT or MT. As transistors VT1, VT2, VT4, you can use any KT315, KT342, KT3102 and the like, VT5 - KT361, KT209, KT3107 and similar with any letter indices. In place of VT3, a medium- or high-frequency transistor is required with a permissible collector pulse current of at least 200 mA. In addition to any KT209, KT208 (the best option), KT502, KT3107, etc. are suitable. Diodes are any of the KD520, KD521, KD522 series, but KD503, KD509 can also be used.

Coil L1, as in the ignition unit, must have an inductance of 5 ... 15 mH and a resistance of 40 ... 80 ohms. If the synthesizer is supposed to work together with ABEZ, then it would be better to install the HL1 LED with a green glow, since the ignition unit already has yellow, orange and red.

The most desirable microcircuits for a synthesizer are the K564 series ICs, because in all electrical and operational parameters they surpass the K561 series ICs, and in the range of permissible temperatures (-60 ... + 125 ° С) they are the most suitable (for the K561 series ICs, only -45 ... + 85 °С). True, the use of the K564 series ICs will add difficulties in installation - they have very thin soft leads, and the interval between them is half that of the K561 series ICs.

Programmable ROM ICs can be taken from any of the KR556 series, including those with a 4-bit output, selecting their composition so that there are 512 words X 8 bits (or 1024X8) to record one RAM characteristic. However, it makes no sense to create a memory capacity of more than 4 characteristics, given the possibility of their shift along the N axis, and in the presence of a corrector transducer (see Fig. 5), also along the axis of the OZ angles. Instead of these ROMs, you can also use reprogrammable LISMOS, for example, K573RF2 (2048X8), which are better consistent with the CMOS structures of the K564 and K561 series ICs.

But with them there is a danger that due to self-erasing of information in 3-5 years, unpredictable changes will appear in the recorded program.

In the converter-corrector, instead of the indicated dual operational amplifier K140UD20, it is even better to use the more heat-resistant KM551UD2A (B) microcircuit or the VAZ-2108 (-09) K140UD1, which has proven itself well in the ignition system. However, many other options are also acceptable, for example, two OS K140UD7 and even KR140UD1. An RS flip-flop and an RS generator (see Fig. 5 and 7) can, of course, be assembled not only on elements with the “2 OR-NOT” logic. Suitable "2 AND-NOT" and a number of others. But in the proposed version, all the minimum necessary elements make up one body, which is not possible in another design.

It should be especially noted that when installing ICs of the K561 or K564 series, it is imperative to strictly comply with the requirements prescribed by technical specifications in order to exclude the possibility of breakdown of their input circuits by electrostatic voltage.

In the synthesizer, you only need to adjust the frequency of the GTI. This is done with a variable resistor R6 at the middle position of the potentiometer R8 slider. Everything else will certainly work fine if the elements are in good condition and correctly soldered. Nevertheless, after assembling and checking the installation, it is necessary to check the ratings of the supply voltages and the performance of the transistors according to the “open-closed” principle. The operation of the counters (zeroing, counting), the correspondence of the PROM output codes to the programming table and all other switching, although for a long time, are simply checked by the step-by-step counting method. To do this, you need to shunt the signal buses F, F and “output 1” of the GTI to “ground” through resistors with a resistance of 10 ... 30 k. After that, disconnect the first two from the ABEZ transistors, and the third from output 10 DD7.3. Then, using one two-position toggle switch, connect the voltage U3 either to bus F or to F, and through the button (or another toggle switch), apply the same voltage to the “output 1” bus.

Further, by setting the voltage U3 on the F bus, which will correspond to the measuring interval, when the button is turned on / off, you can check the operation of the counter SchT, and by switching the toggle switch to the opposite state, the operation of the SChU. By setting any codes at the outputs of the counters in this way, you can check the operation of the PROM and the recorded program by simulating the pulsed power supply of the DD4 IC with a short (up to 1 s) short circuit of the VT2 collector to ground. It is possible to control the coincidence of the output codes of the PROM and the SC by the voltage across the resistor R9, at pin 11 of DD2.2 and at the collector VT1.

"Characteristics switch" OZ SA1 and potentiometer R8 are mounted together with SA1 and SA2 ABEZ on the steering column. In order to easily assess the position of the potentiometer engine by touch, i.e., the approximate value of the GTI frequency and, therefore, the shift in the characteristics of the OZ, a “beak” handle is mounted on its axis. The adjusting elements of the corrector - R3 and R2 are located under the casing of the block, and the axes of these resistors are brought out "under the slot". Balancing potentiometers are actually replaced by pairs of fixed resistors, in which one is selected during tuning.

By selecting the R18C3 circuit, the LED indicator of health is set to a rare, but clearly visible flash at 1500 ... 2000 rpm.

To help the radio amateur 1991

Literature
1. Tyufyakov A. Ignition system without secrets: Sat. Avtomobilist-86.- M.: DOSAAF, 1986.
2. Alekseev S. Shapers and generators on microcircuits of the CMOS structure. - Radio, 1985, No. 8, p. 31.
3. Alekseev S. Application of the K561 series microcircuit.- Radio, 1986, No. 11, p. 3. No. 12, p. 42.
4. Vorobieva N. One-time programmable ROM series KR556. Microprocessor facilities and systems.-M.: GKVTI, 1987, Nos. 1, 2, 3.
5. Shcherbakov V., Grezdov G. Electronic circuits on operational amplifiers. Handbook. - Kyiv, "Technique", 1983.
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