Immediately small FAQ:

1. A full-fledged ignition system consists of 2 parts: an ignition timing generator (FUOZ, Saruman’s own circuit) and a switch, which acts as an amplifier. In fact, FUOZ replaces the centrifugal advance regulator PM-302, which was previously installed in the Urals. The switch can be anything designed to work with a Hall sensor

2. About possible replacement of parts. For self-production, it is envisaged that documentation from this site will be used, including drawings of printed circuit boards. However, with significant modification of the board, you can replace: MC33269DT-5.0 with KR1158EN5V (for a 6-volt on-board network) or with KR142EN5 (7805) for a 12-volt network; LEDs and mode switches - any convenient for installation; BAT254 and SK39 - for any diodes, preferably Schottky, with currents of more than 0.1A and 1A and voltages of more than 25V and 50V, respectively; optocouplers are replaceable with any available transistor ones; transistors BCV48 - on KT502, BCV49 - on KT503, KT3117, BC857 - on KT361, KT3107. Without modification of the board: we will replace the HS-49SM quartz resonator with a ceramic ZTT with built-in capacitors, PIC16F84-04I/P with PIC16F84-10I/P, PIC16F84A-04I/P, PIC16F84A-20I/P.

3. The assembled device does not need debugging, since assembly requires sufficient qualifications to diagnose faults, but just in case, FAQ from the author’s website

4. For what?...

Are paired resistors R29, R30 and R34, R35 used? To reduce the number of values, each pair can be replaced with one 240 Ohm resistor.

Are resistor groups R36-R38, R39-R48, R49-R51 used? Based on the required power and the desire to use parts for SMD mounting. For the same reason, capacitors C23, C24 were chosen.

Are optocouplers installed? For the best decoupling of the microprocessor part and external circuits. At least that’s what I was taught at the Research Institute named after. Kurchatova.

5. LEDs make it easier to diagnose the ignition system. Thus, the absence of HL2 light indicates a lack of power or a malfunction of the DA1 stabilizer; no blinking HL3 - malfunction of the Hall sensor, DA2 stabilizer or short circuit in the Hall sensor circuits; no blinking HL1 - controller DD1 malfunction. (meaning that the remaining LEDs are operating normally).

Microprocessor advance module:
- optimal engine operating mode throughout the entire speed range;
- smooth engine operation, especially at idle;
- no kickbacks at start-up or very weak;
- a change in the advance characteristics is provided (3 graphs);
- security functions;
- spark plug warming function;
- reduction of fuel consumption (IMZ 8.103-10 standard, 60 km/h, highway ~ 5 l/100 km).

Integrated *.3734 class transistor switch:
- improved starting in cold weather and when the battery voltage drops to 7V;
- powerful spark and optimization of coil activation.

Author of the article – Vladimir Shkilmensky, the developer of several devices of this class, who wrote a series of articles about them, including in Radio magazine. Here is an improved version of its development, tested on a large number of cars and having many positive reviews.

The article is reprinted with the written permission of the author.

WHY DO YOU NEED A VOS REGULATOR ON A MICROCONTROLLER

Despite the widespread use of injection (injection) engines, where the preparation of the fuel mixture and ignition timing are controlled electronically, carburetor engines with a mechanical ignition timing regulator will probably be in operation for a long time.

As is known, the power developed by the engine largely depends on how much the ignition timing formed by the centrifugal and vacuum regulators corresponds to the optimal timing. Tyufyakov A., author of the work “Ignition system without secrets” (Collection Avtomobilist-86. - M.: DOSAAF, 1986), believes that even if the centrifugal regulator operates normally, the engine loses 5–10% of power due to the fact that the characteristics of the centrifugal regulator do not correspond to the optimal one. In reality, these losses are much greater, since it is also necessary to take into account:

· various backlashes in the drive of the sensor-distributor (distributor);

· wear of the bearing on which the breaker is mounted (or the Hall sensor in the non-contact version of the ignition system);

· change in the elasticity of the springs of the centrifugal regulator during operation, its inertia, etc.;

· the main thing is that it is impossible, using a simple mechanical device, to reproduce the SOP dependence curve, first along the detonation boundary (up to 2800 rpm), and then along the optimal SOP curve, i.e., to ensure its best performance.

In this regard, an ignition unit was developed - an ignition timing regulator on a microcontroller.

Using an ignition timing regulator on a microcontroller allows you to:

· reduce engine power losses, increase power at low speeds;

· improve engine acceleration dynamics;

· reduce fuel consumption;

· achieve more “smooth” engine operation;

· improve engine starting through the use of multi-spark starting.

The ignition unit - ignition timing regulator - is designed to replace the standard centrifugal and vacuum regulator of VAZ 2101–2107 engines with an electronic analogue made on the PIC12F675 microcontroller. In addition to VAZ 2101–2107, the device (in different versions) was successfully used on carburetor engines VAZ 21213 (Niva), VAZ 2109, GAZ-21 (uprated, AI-92), Toyota Corolla (1988, 2E engine volume 1.3 cubic dm.), MAZDA-323, etc.

The device forms the OZ angle in accordance with Figure 1 (refined characteristics for the VAZ 2103 engine - in the figure there are only 5 OZ graphs out of 32 possible).

Rice. 1. Refined characteristics of the formation of SOP.

The new feature described and applied in this article further improved the vehicle's dynamics compared to previous versions of the program previously reported in other sources.

ADDITIONAL PROGRAM FUNCTIONS

In addition to the above-described regulation of the ignition timing, the program has a number of additional functions that somehow improve engine performance.

Optimization of spark formation. The program has a function to turn off the coil - if there is a constant low level at the input of the GP5 controller, after 2-3 seconds the output of GP1 is set to a high level. If GP5 is constantly high, the program generates multi-spark trigger pulses (see below).

In the range from 370 to 2000 rpm. the program generates an accumulation time of 12 ms; in the range above 2000 rpm. – maximum possible accumulation time. This allows you to obtain spark energy sufficient to reliably ignite the mixture in all engine operating modes and use the B117A ignition coil more efficiently. The heating of the coil at low speeds is reduced, and maximum speeds are easily achieved regardless of the gap in the breaker contacts.

Multi-spark start. In the range from 0 to 370 rpm. Instead of one ignition pulse, the program generates a series of pulses with the following parameters: 2.3 ms is allocated for the spark, 12 ms for energy accumulation in the coil. The slower the starter rotates the crankshaft flywheel (CF), the more sparks occur each time the breaker contacts open (high level at the GP5 input). Multi-spark starting guarantees engine starting in severe frost, carbon deposits on spark plugs and flooded spark plugs.

Adjustment of OZ. This version uses an additional ADC channel AN0, which can be used to shift the SCR by ±10 degrees relative to the original characteristic (Fig. 1).

The correction value is set by potentiometer R4. Instead of R4, in practice it is more convenient to use a switchable voltage divider. When the voltage at input AN0 changes from 0 to +5 V, the graph in Fig. 1 is shifted from –10 to +10 degrees relative to the original. At a voltage equal to 1/2 the microcontroller supply voltage (+2.3 V), the graph corresponds to Fig. 1. This channel can be used to regulate the SOP on a cold and warm engine - control from the choke button. Potentiometer R1 shifts the OZ by +5 degrees when the “suction” is extended on a cold engine (after setting R1, it is better to replace it with two constant resistors). Potentiometer R2 allows you to adjust the SOP manually with the air damper fully open (on a warm engine). The dependence of the voltage on the potentiometer sliders on the angle of rotation is nonlinear. R2 is located inside the car, which allows you to adjust the OZ on the go.

Maintaining XX speed. This version of the program has a function for maintaining idle speed (idle speed) 930 rpm. To do this, on a warm engine (the headlights must be on), use the carburetor adjustments to set the speed to XX 900–930 rpm. When the idle speed deviates from 930 rpm. the program changes the SOP in the range from 7 to 14 degrees, setting the KV speed to 930 rpm. (correction along the AN0 channel is also taken into account and added to the range of 7–14 degrees). In practice, after appropriate adjustment, the speed remains constant when turning on/off the high beam headlights, heated glass and other consumers combined. Previously, you can turn off the “choke” when the engine warms up. You can get stable idle speeds with a lean fuel mixture. On a flat road, the engine “pulls” without jerking or jerking when the gas pedal is released in 1st, 2nd, 3rd and for a short time in 4th gear (this makes it easier to drive in icy conditions, in traffic jams, when driving over bumps - “riding tight”).

Adjustment for vacuum sensor. The program has a function for automatically adjusting to the range of vacuum changes in the engine intake manifold, which simplifies the setup of a homemade vacuum sensor, and also allows you to use an industrial absolute pressure sensor (DAP 45.3829). The program independently determines the type of discharge sensor (by the maximum voltage at input AN2), therefore, in order not to mislead the program, do not configure the homemade sensor for a voltage greater than 2.3 V.

When using a homemade inductive vacuum sensor, the setting is reduced to setting the maximum voltage at the ADC input in the absence of vacuum and the minimum voltage at maximum vacuum (Fig. 2). To ensure greater accuracy in the formation of the SPD (in accordance with Fig. 1), the inductive sensor should be configured so that the maximum voltage at the ADC input is from 1.5 to 2.3 V, and the minimum is equal to or less than 0.9 V.

Rice. 2. Setting up a homemade inductive vacuum sensor.

The sensor is configured by selecting C3 and R10 before installing the unit on the car. Vacuum is simulated by moving the rod of the vacuum chamber from one extreme position to another.

APPLICATION WITH CONTACT IGNITION SYSTEM

If the car has a contact ignition system (breaker and coil B117A), the ignition unit is assembled according to the diagram in Fig. 3.

Rice. 3. Device diagram for a contact ignition system.

A breaker is used as a TDC sensor, a homemade inductive vacuum sensor (this option is described in detail in the Radio magazine, No. 11, 2008, p. 36), but DBP 45.3829 can also be used (for connection, see Fig. 4a, Fig. 4b).

APPLICATION WITH CONTACTLESS IGNITION SYSTEM

This version of the program can be used to work with a contactless ignition system (instead of a breaker - a Hall sensor). The OZ angle former is assembled according to the diagram in Fig. 4a (for ignition coil 27.3705) or Fig. 4b (for coil B117A). If necessary, you can use a homemade inductive vacuum sensor (connected in the same way as in Fig. 3).

Rice. 4a. Device diagram for a contactless ignition system (coil 27.3705).

Rice. 4b. Device diagram for a contactless ignition system (coil B117A).

The operation of the driver was tested on VAZ 2109 and VAZ 21213 (Niva) cars.

IMPORTANT DIFFERENCE FROM PREVIOUS VERSIONS OF THE PROGRAM

Below is a table for generating the key closing time. The red color in the table indicates the accumulation time, which is insufficient for reliable ignition of the mixture. Under “MK is not normal.” implies the accumulation time generated by versions of programs from QRZ.RU (03.2008) and FTP of the Radio magazine (11.2008).

Effect of key closure time formation.

The table shows that older versions with a breaker as a TDC sensor and a B117A coil can form a spark with sufficient energy only at a Closed State Angle (USA) of the breaker contacts equal to 65 degrees.

DIAGRAMS OF DEVICE OPERATION IN DIFFERENT MODES

In Fig. 5, Fig. 6, Fig. Figure 7 shows the pulse shapes at the GP5 input and GP1 output of the microcontroller at different engine speeds.

Rice. 5. Formation of sparks when starting the engine.

Rice. 6. Formation of sparks at 900 rpm. (idling).

Rice. 7. Formation of sparks at 3300 rpm. (Work mode).

INSTALLING THE DEVICE ON A CAR

When installing the device on a car, the operation of the centrifugal and vacuum regulators is blocked: the weights of the centrifugal regulator must be secured using wire brackets instead of standard springs. The bearing race, on which the contact group of the breaker or the Hall sensor in the non-contact version is attached, is fixed with a metal plate connecting the race pin and the distributor body. The vacuum sampling hose for the OP angle regulator on the microcontroller is connected to the vacuum sampling pipe on the carburetor or intake manifold.

Any option can be used in a simplified form, i.e. without adjustment for vacuum. The standard vacuum regulator is not blocked in this case; input AN2 is connected to +5 V through a 10 kOhm resistor. The efficiency of the device in a simplified version will decrease. If input AN0 is not used, it must be supplied with a voltage equal to 1/2 of the microcontroller power supply (+2.3 V) from the divider through a 10 kOhm resistor.

The gap between the breaker contacts is set to the minimum possible (to reduce wear on the breaker cam), but ensures clear opening and closing of the contacts. After this, the initial angle of OZ is set: it must be equal to zero in relation to TDC and set according to the marks on the crankshaft pulley and the cylinder block when the engine is not running.

The transition to a microcontroller-based ignition system can be done in stages. You first need to outline these stages for yourself, so that later there will be fewer alterations to the circuit.

· First, the block is assembled according to the diagram in Fig. 3 (for contact ignition system) or according to Fig. 4a/4b (for contactless ignition system). Unused ADC inputs are disabled (see above).

· Then the board is installed on the car, while the weights of the CR distributor are fixed. That's it, you can ride for your pleasure!

· If in the future you are going to connect a homemade vacuum sensor, use a slightly larger case in order to then place the sensor in it (if you plan to connect the DBP 45.3829, install a 5-volt stabilizer in the circuit to power the DBP, preferably on a zener diode and a resistor - like this more reliable).

The figure below shows an example of the design of an ignition unit with a homemade vacuum sensor

Of course, you shouldn't expect miracles from this device. “Zhiguli” will not turn into “Ferrari”, but they will drive very decently and at the same time consume noticeably less gasoline.

It is assumed that the engine is in good condition, the carburetor is adjusted in accordance with factory requirements.

If you fail to replicate the device, do not scold the author of the article and his program: read the text on the page carefully and you will find the reason for the failure.

The author does not recommend making changes to the circuits: apart from deteriorating performance and reliability (and sometimes complete inoperability), nothing will be achieved (this is especially true when replacing KS147 with 7805 or EH5). External devices (homemade tachometer) should be connected to the microcontroller ports via 3–10 kOhm resistors, and the resistors should be located on the board of the ignition unit - driver (the driver will work even if the tachometer connecting wires are shorted to the case). You cannot leave programmed but unused microcontroller inputs “in the air” (i.e., unconnected).

Optional. It is possible to significantly reduce the error in the formation of the SPD at low speeds by installing a TDC sensor on the crankshaft pulley. Two options for implementing this option are discussed in the original author's article. Their implementation is quite labor-intensive and is not necessary when using a controller on a microcontroller, so they are not presented here. Those interested can familiarize themselves with them.

MICROCONTROLLER FIRMWARE AND PRINTED BOARD

Printed circuit board(pictures on the right) is universal and suitable for the manufacture of any version of the device. The elements are installed depending on the application. The board is designed to use SMD resistors, but if necessary, you can use MLT-0.125 resistors.

All parts are located on the conductor side; the foil on the opposite side of the board serves as a common wire and shield. Holes are drilled at the points where the leads of the parts connect to the common wire. The KT898A transistor is fixed to the radiator (metal casing) through a mica or fluoroplastic gasket.

Firmware check in simulators it’s a waste of time, they (simulators) won’t tell you anything smart. If you want to make sure it works, check it on a breadboard using a two-channel oscilloscope and a PIC generator. Without instruments, the functionality of the microcontroller ignition system can be checked as follows: connect a spark plug to the high-voltage wire of the coil, open the breaker contacts (Fig. 3) and turn on the ignition. The program will operate in multi-spark start mode. For the circuit Fig. 4a, Fig. 4b, turn off the sensor and short-circuit the driver input to ground (the MK input cannot be connected directly to ground - it is possible that at this moment it is configured as an output, and this can damage the microcontroller). This mode can be used for burning carbon deposits and drying spark plugs, but, as a rule, with the multi-spark starting function there is no need for this - the engine starts reliably even with heavy carbon deposits on the spark plugs and with flooded spark plugs.

Download PCB drawing: F675OK.BAK

Download firmware for PIC12F675: F675OK.HEX

You can purchase a blank PIC12F675 controller at a retail outlet. You can flash a program into a microcontroller using an industrial or home-made programmer device, independently or to order.

ATTENTION! From us you can purchase a PIC12F675 microcontroller with the F675OK.HEX program already flashed at a fixed price of 250 rubles!

When ordering more than 5 pieces, the price is reduced.

Note. We do not sell this software. We provide services for firmware and supply of microcircuits. The program is distributed free of charge with the permission of the author.

PLACE YOUR ORDER

Use the form below to submit an order for a microcontroller with the above firmware F675OK.HEX. Please fill it out as completely as possible.

Read more about everything in the article.

So, many articles have already been written about FUZ, I will tell you briefly.
FUOZ- Ignition timing generator. It is needed for the proper operation of the engine (especially 4-stroke engines).
Ignition timing- a very important parameter that greatly affects the correct operation of the motor. It primarily depends on the engine speed: the higher the speed, the greater the ignition timing should be, because for maximum power the mixture must be ignited earlier.
FUOZ- automatic ignition timing regulator. It is connected to the signal wire of the hall sensor or optical sensor. In this case, the initial ignition timing for two-stroke engines should be 0.7-1 mm before TDC.
For four stroke engines (URAL/DNEPR), it is necessary to set 1mm before TDC.
I produce fuoz, famous since 2002 Saruman, the creator himself was also from Ryazan, like me, but he never sold ready-made blocks, he just created it.

How to connect and configure the ignition (BSZ) with Saruman's fuoz

If you already have a BSZ with a hall sensor or optics (optical sensor), then installing the fuoz takes 15-20 minutes.
1. It is necessary to connect the fuoz, each manufacturer has its own connection designations

In the photo (left) you can see the designations “+”, “-”, “in”, “out”
“+” is a power plus
"-" minus power
“in” signal wire from hall sensor or optics
“out” output to the switch (pin 6 of the switch)
At the top of the board there are the designations “g3”, “g2”, “f2”, “f1”
"f1" function first
"f2" second function
“g2” advance graph No. 2
“g3” lead chart No. 3
To enable the desired function or schedule, you need to close the contact to minus; to disable it, you need to open the contact.

Connection diagram of BSZ with Fuoz Saruman for clarity

Fuoz is manufactured entirely at the factory (boards and parts are soldered in)

Setting up BSZ with Fuoz Saruman

We unscrew the spark plug, find TDC and return it 1 mm back, this is easy to do with a caliper

Now the important moment!!!

Two types of modulators are suitable for fuoz - 60 degree petals and 120 degree petals.
with the petals at 60 degrees the spark will be as usual at EXIT curtains from the sensor.
With petals of 120 degrees, the spark will be at ENTRANCE modulator into the sensor.
For easy setup, there is a setup LED on the back of the board, so setup is very easy.

Well, that’s it, now a little bit of nonsense, I also have optical sensors with double indication for configuration (one LED lights up when the modulator is in the sensor, the second when it’s not in the sensor)

There is also 2 in 1: fuoz and optics (but fuoz is different):

And my latest development of optics is not reflection:

Update! Now on sale: fuoz in a housing, wiring, pads, modulators and faceplates.