SU1332952A2 - Battery ignition system of i.c.engine - Google Patents

Description

The invention relates to a pulse technique and can be used in ignition systems for internal combustion engines.

The aim of the invention is to raise the system over the threshold of the system by eliminating the effect of the increased switching frequency of the contacts of the switch on it.

The drawing shows the electrical circuit diagram of the ignition system.

The system contains a single-contact transistor converter 1, consisting of a transformer 2 with three windings: feedback 3, a collector 4 and an output 5, a TcSistor 6 and resistors 7.8 and 9, diodes 10 and 11 and a capacitor 12, a storage capacitor 13 connected parallel to the output winding 5 of the voltage converter through the diode I, resistive divider 14, mounted on a potentiometer connected in parallel to the storage capacitor 13. Amplifier 15 on the trans. Sistors 16 and 17, the base of the input transistor 16 which is connected with. middle point of divider 14 (with noTeHUHOMetpa DVI7KKOM). The output transistor 17 emitter is connected to the first power line, and its collector is connected to the connection point of resistor 9 to the base of transistor 6 of the voltage converter through diode 18, and the emitter of transistor 6 is connected to the first power line through diode 19, pulse transformer 20, in parallel The primary winding 2J of which is connected to a diode 22, the anode of which is connected through a limiting resistor 23 to the first power supply bus. The secondary winding 24 of the pulse transformer 20 is connected to the input of the thyristor 25, which through the primary winding 26 of the ignition coil 27 is connected in parallel to the storage capacitor 13. The ignition coil 27 fuses the secondary winding 2 The cathode of the diode 22 is connected to the second power bus through the contacts of the chopper 29, Additional capacitor 30, one plate of which is connected to the point of connection of the limiting resistor 23 and the primary winding 21 of the pulse transformer 20. Another plate is added to the capacitor. 30 is connected to

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the first terminals of the first and second additional resistors 31 and 32 / the second terminals of which are connected respectively to the cathode of the first and the anode of the second additional diodes 33 and 34. The anode of the first additional diode 33 is connected to the second power bus, and the cathode of the second additional diode is connected to the input of the amplifier 15 .

The system works as follows. ; .

After the power is supplied, the voltage converter 1 starts operating. Negative voltage from the splitter across the resistors 7.8 and 9 goes to the base of the transistor 6, as a result of which the last one opens, the collector current of the transistor 6 flows. through the winding 4 of the transformer 2, as a result of which a negative voltage is induced in the winding 3 of the transformer, which through the diode 10 5 and the resistor 8 applies to the base of transistor 6 and opens it completely. The current in the winding 4 of the transformer 2 is increased linearly (meaning, the transformer is not saturated) as long as the condition

,,-)&-R. where j is the collector current;

Ig - base current ;.

p is the current gain of transistor 6;

However, the base current of transistor 6 is limited by the value of resistor 8 and, therefore, the collector current of this transistor cannot be greater than 1 3g | Having reached this value, the collector current ceases to increase, and the voltage in the winding 3 of the transformer changes its sign. Transistor 6 is locked. The positive-locking voltage to the base-emitter junction of transistor 6 comes from winding 3 through resistors 7 and 8, the magnitude of the 3Tofo voltage is limited by the division factor of the resistors 7.8 and 9.

The capacitor 12 reduces the amplitude of the positive pulse at the base of the transistor 6 of the converter appearing at the moment of locking the transistor due to the finite value of the recovery time of the reverse resistance of the diode 10.

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A positive pulse from the output winding, 5 through diode 11, charges accumulative capacitor I3 to a voltage determined by the energy accumulated in the magnetic field of the transformer 2 and the capacitance of the storage capacitor 13.

This voltage, as a rule, is much less than the voltage required for normal operation of the ignition system.

Then the above processes are repeated. The voltage converter 1 continues to operate and the voltage across the storage capacitor 13 increases in steps until it reaches the norm. At the same time, the transistors 16 and 17 of the amplifier 15 are opened. The collector-emitter transition of the open transistor I7 through the diode 18 shunts the base of the transistor 6 of the converter, and the latter stops working. Reliable locking of the transistor 6 provides the diode 19 to compensate for the voltage drop in the diode 18, which in turn prevents polkite voltage from the winding 3 of the transformer 2 to the collector of the transistor 17. The transistor 6 remains locked and the converter 1 does not work until as long as the voltage on the storage capacitor 13 is normal. However, as soon as the voltage on the storage capacitor decreases, for example, due to leakage or discharge through the ignition coil, the transistors 16 and 17 of the amplifier 15 are closed, the converter starts up again and the storage capacitor again recharges to a predetermined voltage.

The voltage divider 14 is used to regulate the voltage on the storage capacitor. When the potentiometer slider moves up (according to the diagram), the transistors unlock at a lower voltage on the storage capacitor 13, and, conversely, when the slider of the potentiometer moves down - at a higher voltage.

When the interrupter contacts close, the bodies pass through the limiting resistor 23 and the diode 22 begins to flow. The voltage across the winding 21 of the transformer 20 is limited by a diode 22, in connection with

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What is the amplitude of the negative pulse on the control electrode of the thyristor 25 at the time of contact closure of the predzhatel does not exceed 0.35 V. The limiting voltage on the winding 21, in addition, provides an increase in the time of current rise in the winding, which eliminates the influence bounce contacts breaker.

At the moment of the contact of the breaker 29, the current in the winding 21 ceases, and a positive pulse occurs in the winding 24, which nepe-j switches on the thyristor 25. Charged to a voltage of approximately 350 V, the storage capacitor 13 is connected to the primary winding 26 of the ignition coil 27. In The secondary winding .28 of the ignition coil produces a high voltage pulse, which through the distributor goes to the spark plugs (the latter are not shown in the drawing). t

Simultaneously with the opening of the contacts, the chopper starts charging. Additional capacitor 30 along the circuit: first power supply bus, resistor 23, additional capacitor 30, second additional resistor 32J second additional diode 34, base-emitter junction of transistor 16, second power bus 8 "1. This opens the transistors 16 and 17 of the amplifier 15. The transition of the collector-emitter of the open transistor 17 through the diode 18 bypasses the base of the transistor 6 of the converter, the latter is stopped and the diode 11. will open as soon as the voltage on the cumulative cow generator 13 becomes negative. Permanently charged

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additional capacitor

30 must be within

S where (is the time, which is the voltage on the storage capacitor 13 drops to zero; 7. - the duration of the sparking}

 The first additional resistor 31 and the first additional diode 33 are needed to discharge the additional capacitor 30 after closing the breaker contacts.

Thus, the introduction of an additional capacitor into the circuit, two re51

of the resistors and two diodes allowed to eliminate the dangerous effect of the increased switching frequency of the chopper by turning off the single-ended converter at the moment of chopper opening, which distinguishes the proposed system from the prototype, increasing its reliability and expanding the possibility of practical use.

Claims (1)

Invention Formula Battery ignition system dp internal combustion engines auth.St. No. P43420, characterized in that, in order to increase reliability, additional 32952 has been introduced into it. a capacitor, the first and second additional resistors, and the neji and second additional diodes), with one output of the additional capacitor connected to the input form of the secondary chain, another its output connected to the first terminals of the first and second additional resistors, 10, the second output of the first additional resistor is connected to the cathode of the first additional diode, the anode of which is connected to the second power bus, the second output of the second additional resistor is connected to the anode of the second additional diode, the cathode of which is connected to the input of the transistor amplifier. 46 Compiled by L.Simonova Editor A.Kondrakhina Tehred L.Serdyukova Proofreader E.Roshko Order 2450 Circulation 338 Subscription VNIIPI USSR State Committee on deLam inventions and discoveries 113035, Moscow, Moscow, Zh-35, Raushsk nab. 4/5 Prpichrolgtionno-polygraphic enterprise, Uzhgorod, Projecto st., 4