SU439622A1 - Battery ignition system - Google Patents

Description

one

Battery ignition systems are known for internal combustion engines comprising a transistor voltage converter on a transformer with a trigger, a rectifier, a storage capacitor, a thyristor, an ignition coil and a stabilization circuit. The disadvantage of such ignition systems is the dependence of the secondary voltage on the primary voltage. During the cold season, even when the battery pack is in a normal state, the voltage of the latter when starting the engine with a starter can decrease so much that the sparking energy is deficient in: Noah for reliable starting of the engine. In the buffer mode of operation (when the car is moving), the voltage of a charged battery can exceed its nominal value by 1.2-1.3 times. In this case, respectively, the secondary voltage also breaks down, which necessitates the use of more high-voltage elements of the ignition system.

The proposed ignition system ensures the stability of secondary radiation in a wide range of temperatures from –60 to –70 ° C. This is achieved by the fact that the stabilization circuit is made on two transistors, the base of one of which is connected to the connection point of the transformer primary transformer and resistor, and the base of the other to the junction point of the Zener diode and resistor, and the collector of this transistor is connected through a capacitor to the base of the first transistor of the trigger . In this case, the trigger performs only the functions of a switching device, the trigger threshold of which is regulated by the stabilization circuit.

The use of the stabilization circuit and the limitation of the trigger function allow one to increase the thermal stability of the ignition system and simplify the process of its adjustment after manufacture.

In the drawing, the Prince pialia electrical circuit of the described ignition system was given.

The ignition system consists of a trigger on transistors 1 and 2 with a feedback resistance of 3, a power transistor switch 4, a voltage converter that includes a transformer 5n diode 6, a stabilization circuit made on transistors 7 and 8 and a zener diode 9, an interrupter 10 , a storage capacitor 11, a tyre switch 12, a discharge diode 13 n of the ignition coil 14. The trigger on transistors 1 and 2 is designed to control the trap; NCIT {p NYM key 4, equal to, in turn, the voltage converter. Stabilization scheme is used to fix the moment of rupture.

current in the converter. The breaker 10 provides synchronization of the system for zigigan. In the condenser 11, sparking energy is stored.

The ignition system works as follows.

in a way.

After the power is turned on, due to the presence of the resistor 3, the trigger is set to the first stable state — transistor 1 is open and transistor 2 is closed. Consequently, the traisistor 4 is also closed - the power switch is open, and there is no current in the primary circuit of the transformer 5. Transistor 7 is open, and transistor 8 is closed.

If the constants of the chopper 10 are closed, then the capacitor 15 is charged through the resistor 16. The diode 17 is closed. Storage capacitor 11 is discharged, thyristor 12 is turned off.

At the moment of opening the contacts of the chopper, the charged capacitor 15 through the resistor 18 and the diode 17 is connected to the trigger input. The diode 17 opens, and the positive voltage from the capacitor 15 goes to the base of the transistor 1, as a result the trigger goes to the second steady state when the transistor 1 is closed and the transistor 2 is open. Unlocking the transistor 2 causes unlocking of the transistor 4, which connects the primary winding of the transformer 5 to the power supply. Through the primary winding of the transformer 5 begins to flow a linearly increasing current. Voltage pulses appear on both halves of the transformer secondary winding. The positive voltage from the beginning of the secondary winding through the capacitor 19, the resistor 20 and the diode 21 is supplied to the control electrode of the thyristor 12. However, since the voltage on the thyristor anode at this time is equal to the cup (storage capacitor 11 is not charged), the thyristor remains off . Negative voltage from the end of the secondary winding through diode 6 to the capacitor 11 does not pass.

As the current through the primary winding of the transformer 5 increases, the voltage across the resistor 22 increases and, when o "reaches the stabilization voltage of the zener diode 9, the stabilizing transistor 8 opens and the transistor 7 closes. A negative voltage jump from the collector of transistor 7 through the capacitor 23 enters the base of the transistor 1 of the flip-flop, as a result of which the flip-flop returns to the first steady state — transistor 1 opens and transistor 2 closes. The transistor 4 is also closed, and the current in the primary circuit of the transformer 5 is stopped. In this case, the energy stored in the magnetic field of the transformer creates voltage surges in its windings. A positive voltage surge from the end of the secondary winding through the diode 6 charges the storage capacitor 11 to a voltage of 350-400 V.

Neglected or thought that

the energy accumulated in the magnetic field of the transformer (L / p2 / 2), at the moment of breaking the current is transferred to the energy of the electric field of the capacitor (), receive the expression for voltage on the storage capacitor

and, / p 1 /,

where / p - the magnitude of the current gap;

L - inductance of the primary winding

transformer;

C - storage capacitor capacitance 11.

Thus, the charge voltage of the storage capacitor is determined by the magnitude of the breaking current and does not depend on the supply voltage.

After the contacts of the chopper are closed, the capacitor 15 is recharged, and after opening, the described processes are repeated with the difference that at the time of the opening of the contacts of the chopper, the thyristor 12 switches and connects the storage capacitor 11, which is charged to 350-400 V, to the primary winding of the ignition coil.

The stabilization scheme, which fixes the moment of current rupture in the converter, ensures the continuity of the rupture current when changing over a wide range as temperatures

(from -60 to -80 ° C) and the supply voltage (from 6.5 to 17V), as a result of which the storage voltage of the storage capacitor and the secondary voltage become practically independent of the indicated factors.

Subject invention

A battery ignition system for internal combustion engines comprising a transistor voltage converter on a transformer with a trigger, a rectifier, a storage capacitor, a thyristor,

an ignition coil and a stabilization circuit, characterized in that, in order to increase thermal stability, the stabilization circuit is implemented on two transistors, the base of one of which is connected to the junction point of the transformer primary transformer and resistor, and the base of the other, to the junction point of the Zener diode and resistor, moreover, the collector of this transistor is connected through a capacitor to the base of the first transistor

trnggera.