CN218446428U - Ignition power inverter control circuit based on singlechip - Google Patents

Abstract

The utility model relates to an engine ignition technical field discloses an ignition power inverter control circuit based on singlechip, including input voltage Vi, resistance R1, resistance R15, resistance R16, resistance R17, resistance R18, resistance R19, resistance R120, resistance R21, resistance R22, resistance R23, resistance R24, singlechip, flyback transformer T1, rectifier silicon pile D1, energy storage capacitor C12, discharge tube Q11; the positive pole of the input voltage Vi is connected with the second ADC pin of the single chip microcomputer through a resistor R16, and the negative pole of the input voltage Vi is connected with the second ADC pin of the single chip microcomputer through a resistor R17.

Description

Ignition power inverter control circuit based on singlechip

Technical Field

The utility model relates to an engine ignition technical field, specific ignition power inverter control circuit based on singlechip that says so.

Background

Under various working conditions and using conditions of the engine, the ignition system needs to generate electric sparks in time and reliably and sufficiently strong to ignite combustible mixed gas in the combustion chamber. The ignition device is the main part of the engine ignition system, and the ignition system is composed of the ignition device, an ignition cable and an ignition electric nozzle, and the ignition system has the function of converting low-voltage direct current into high-voltage pulse required by the ignition electric nozzle to generate high-energy spark.

The circuit is divided into a contactless type and a mechanical vibrator according to the circuit form, and the application of the contactless type and the mechanical vibrator is wide. The front stage of the mechanical vibrator type ignition device mainly adopts a circuit form that a mechanical vibrator inversion step-up transformer is adopted, and a gas discharge tube is adopted as a discharge switch at the rear stage. Although the mechanical vibrator inversion step-up transformer has the defects of large volume, large mass, short service life, strong electromagnetic radiation and the like, the mechanical vibrator inversion step-up transformer has the advantage of wide working environment temperature range and is mainly applied to occasions with the environment temperature higher than 125 ℃. The front stage of the contactless ignition device mainly adopts a circuit form that a semiconductor power tube is inverted and boosted, and the rear stage adopts a gas discharge tube or a power semiconductor as a discharge switch. The semiconductor power tube inversion booster circuit widely adopts the transistor self-oscillation flyback conversion principle (RCC), and is a high-efficiency circuit which can be formed by a few devices.

According to the transistor self-oscillating flyback principle (RCC), its input power is greatly affected by the supply voltage: when the power supply voltage is lower, the input power is reduced due to the feedback current; at a low ambient temperature, the input power is reduced due to the smaller current amplification factor of the transistor. The reduction in input power ultimately results in a reduction in the spark frequency of the ignition device, which is detrimental to successful engine starting.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the defects of the background art, and provides an ignition power inverter control circuit based on a single chip microcomputer, wherein the single chip microcomputer is used as a core control unit, and the program of the single chip microcomputer adopts digital control logic, so that the problem that key control parameters change along with the power supply voltage is avoided; the single chip microcomputer is used as a core control unit, the output of different spark frequencies can be completed by adjusting the program of the single chip microcomputer and adopting uniform hardware equipment, and the debugging difficulty is reduced; the power field effect transistor is used as a switching device of the main loop, so that the switching working frequency is improved, and the influence of temperature on the switching device is avoided.

The utility model discloses a following technical scheme realizes:

an ignition power inverter control circuit based on a single chip microcomputer comprises an input voltage Vi, a resistor R1, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R120, a resistor R21, a resistor R22, a resistor R23, a resistor R24, the single chip microcomputer, a flyback transformer T1, a rectifier silicon stack D1, an energy storage capacitor C12 and a discharge tube Q11;

the positive pole of the input voltage Vi is connected with a second ADC pin of the single chip microcomputer through a resistor R16, and the negative pole of the input voltage Vi is connected with the second ADC pin of the single chip microcomputer through a resistor R17; the positive electrode of an input voltage Vi is connected with the drain electrode of a field effect tube Q2 through a primary coil of a flyback transformer T1, the grid electrode of the field effect tube Q2 is connected with a control pin of the single chip microcomputer through a resistor R15, and the source electrode of the field effect tube Q2 is connected with a first ADC pin of the single chip microcomputer; the source electrode of the field effect tube Q2 is connected with the drain electrode of the input power supply GN through the resistor R1, and the drain electrode of the field effect tube Q2 is connected with the drain electrode of the input power supply GN through the resistor R19 and the resistor R20 which are connected in series; a third ADC2 pin of the singlechip is connected between the resistor R19 and the resistor R2;

two ends of a secondary coil of the flyback transformer T1 are connected in series through the rectifier silicon stack D1 and the energy storage capacitor C12 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R21 and the resistor R23 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R222 and the resistor R24 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11 and the electric nozzle in sequence.

Further, the type of the single chip microcomputer is ATMEGA8A;

an ADC0 pin of a singlechip with the model number of ATMEGA8A is used as a first ADC pin;

an ADC1 pin of a singlechip with the model number of ATMEGA8A is used as a second ADC pin;

an ADC2 pin of a singlechip with the model of ATMEGA8A is used as a third ADC pin;

and a PB0 pin of the singlechip with the model number of ATMEGA8A is used as a control pin.

Compared with the prior art, the utility model, following advantage and beneficial effect have:

the utility model takes the single chip microcomputer as a core control unit, and the program of the single chip microcomputer adopts digital control logic, thereby avoiding the problem that key control parameters change along with the power supply voltage; the single chip microcomputer is used as a core control unit, the output of different spark frequencies can be completed by adjusting the program of the single chip microcomputer and adopting uniform hardware equipment, and the debugging difficulty is reduced; the power field effect transistor is used as a switching device of the main loop, so that the switching working frequency is improved, and the influence of temperature on the switching device is avoided.

Drawings

The technical solutions described below will be clearly and completely described with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention.

Fig. 1 is a schematic structural diagram of an ignition power inverter control circuit based on a single chip microcomputer provided by the present invention;

fig. 2 is a schematic view of the work flow of the present invention.

Detailed Description

The above-mentioned aspects of the present invention will be further described in detail with reference to the following embodiments. This should not be understood as limiting the scope of the above-described subject matter of the present invention to the following examples only. Various substitutions and alterations can be made according to the ordinary skill in the art and the conventional means without departing from the technical idea of the invention.

Example 1:

the embodiment provides an ignition power inverter control circuit based on a single chip microcomputer, which comprises an input voltage Vi, a resistor R1, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R120, a resistor R21, a resistor R22, a resistor R23, a resistor R24, the single chip microcomputer ATMEGA8A, a flyback transformer T1, a rectifying silicon stack D1, an energy storage capacitor C12 and a discharge tube Q11;

the positive pole of the input voltage Vi is connected with the ADC1 pin of the single chip microcomputer ATMEGA8A through a resistor R16, and the negative pole of the input voltage Vi is connected with the ADC1 pin of the single chip microcomputer ATMEGA8A through a resistor R17; the positive electrode of the input voltage Vi is connected with the drain electrode of a field effect tube Q2 through a primary coil of a flyback transformer T1, the grid electrode of the field effect tube Q2 is connected with a PB0 pin of the single chip microcomputer ATMEGA8A through a resistor R15, and the source electrode of the field effect tube Q2 is connected with an ADC0 pin of the single chip microcomputer ATMEGA8A; the source electrode of the field effect tube Q2 is connected with the drain electrode of the input power supply GN through the resistor R1, and the drain electrode of the field effect tube Q2 is connected with the drain electrode of the input power supply GN through the resistor R19 and the resistor R20 which are connected in series; an ADC2 pin of the single chip microcomputer ATMEGA8A is connected between the resistor R19 and the resistor R2;

two ends of a secondary coil of the flyback transformer T1 are connected in series through the rectifier silicon stack D1 and the energy storage capacitor C12 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R21 and the resistor R23 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R222 and the resistor R24 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11 and the electric nozzle in sequence.

The working voltage of the ignition device, namely the input voltage Vi, the positive pole of the Vi is connected to the negative pole of the Vi through the primary coil of the flyback transformer T1 and the field effect tube Q2 to form a loop. The on-off of the field effect transistor Q2 is controlled by a PB0 pin of the single chip microcomputer ATMEGA8A, the PB0 is switched on when outputting a high level, and the PB0 is switched off when outputting a low level. When the field effect tube Q2 is conducted, the primary coil of the flyback transformer T1 is charged to store energy; when the field effect transistor Q2 is turned off, the energy released by the secondary coil of the flyback transformer T1 is charged to the energy storage capacitor C12 through the rectifier silicon stack D1, that is, the field effect transistor Q2 is turned on and off once and is charged to the energy storage capacitor C12 once, and the field effect transistor Q2 is turned on and off once, which is an inversion process. When the energy storage capacitor C12 is charged until the voltage Vc at two ends reaches the discharge voltage Vt of the discharge tube Q11, the discharge tube Q11 is conducted, and the energy of the energy storage capacitor C12 is released through the ignition nozzle to generate primary ignition.

According to the flyback conversion principle, the source electrode of the field effect transistor Q2 is connected to the negative terminal (GND) of the input power supply through the sampling resistor R1, the sampling resistor R1 is connected with the primary coil of the flyback transformer T1 in series, the current passing through the primary coil of the flyback transformer T1 is equal to Vs/R1, the waveform is consistent with Vs, and the peak current of the primary coil is recorded as Ip.

Let flyback transformer T1 primary coil inductance be L1, field effect transistor Q2 conduction time be T1, then have:

as can be seen from equation (1), t1 is determined by the input voltage Vi and the primary coil peak current Ip. When the input voltage Vi is constant, the peak value I of the current of the primary coil can be controlled _p Indirectly controlling the conduction time t1, and calculating I by the flyback conversion principle _p The single chip microcomputer ATMEGA8A measures the source voltage Vs of the field effect transistor Q2 in real time through an ADC0 pin, can calculate the current i = Vs/R1 of the primary coil, and turns off the field effect transistor Q2 when monitoring that the current i of the primary coil reaches the set peak current Ip.

According to the flyback conversion principle, the drain voltage Vd of the field effect transistor Q2 and the voltage Vo of the secondary coil of the flyback transformer T1 have the following relations:

V _d ＝V _i +N(V _c +V _d1 )……………………………………………(2)

the condition satisfied by the formula (2) is that the secondary coil has energy release, and when the energy release is completed and the current of the secondary coil is zero, V is _d ＝V _i 。

Therefore, can pass through the monitoring V _d The point in time at which the secondary coil energy release is complete is captured. When V is _d When the cliff type descending occurs, the energy release of the secondary coil is completed, and the field effect tube Q2 is controlled to be turned off at the moment, namely, the turn-off time t2 is indirectly controlled.

Referring to fig. 2, the control flow of the ignition inverter control circuit is as follows: a PB0 pin of the single chip microcomputer ATMEGA8A outputs high level to control a field effect transistor Q2 to be conducted to store energy for a primary coil of the flyback transformer T1, meanwhile, the single chip microcomputer ATMEGA8A measures source voltage Vs of the field effect transistor Q2 in real time through an ADC0 pin, and current i = Vs/R1 of the primary coil of the flyback transformer T1 is calculated; when I reaches I _p When the voltage of the energy storage capacitor C12 is higher than the preset voltage, a PB0 pin of the single chip microcomputer ATMEGA8A outputs low level to control the disconnection of the field effect transistor Q2, the secondary coil of the flyback transformer T1 starts to release energy to charge the energy storage capacitor C12, and meanwhile, the leakage of the field effect transistor Q2 is measured through the ADC2 pin period of the single chip microcomputer ATMEGA8AAnd (3) when the voltage Vd is equal to Vd and falls off the cliff, a PB0 pin of the single chip microcomputer ATMEGA8A outputs a high level to control the field effect transistor Q2 to be conducted again, and the operation is circulated.

The above, only the preferred embodiment of the present invention is not intended to be a limitation of the present invention in any form, and all the technical matters of the present invention are all within the protection scope of the present invention to any simple modification and equivalent changes made by the above embodiments.

Claims (2)

1. The utility model provides an ignition power inverter control circuit based on singlechip which characterized in that: the circuit comprises an input voltage Vi, a resistor R1, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R120, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a singlechip, a flyback transformer T1, a rectifier silicon stack D1, an energy storage capacitor C12 and a discharge tube Q11;

the positive pole of the input voltage Vi is connected with a second ADC pin of the single chip microcomputer through a resistor R16, and the negative pole of the input voltage Vi is connected with the second ADC pin of the single chip microcomputer through a resistor R17; the positive electrode of the input voltage Vi is connected with the drain electrode of a field effect tube Q2 through a primary coil of a flyback transformer T1, the grid electrode of the field effect tube Q2 is connected with a control pin of the single chip microcomputer through a resistor R15, and the source electrode of the field effect tube Q2 is connected with a first ADC pin of the single chip microcomputer; the source electrode of the field effect transistor Q2 is connected with the drain electrode of the input power GN through a resistor R1, and the drain electrode of the field effect transistor Q2 is connected with the drain electrode of the input power GN through a resistor R19 and a resistor R20 which are connected in series; a third ADC2 pin of the singlechip is connected between the resistor R19 and the resistor R2;

two ends of a secondary coil of the flyback transformer T1 are connected in series through the rectifier silicon stack D1 and the energy storage capacitor C12 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R21 and the resistor R23 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11, the resistor R222 and the resistor R24 in sequence; two ends of the energy storage capacitor C12 are connected in series through the discharge tube Q11 and the electric nozzle in sequence.

2. The ignition power inverter control circuit based on the single chip microcomputer as claimed in claim 1, wherein: the type of the single chip microcomputer is ATMEGA8A;

an ADC0 pin of a singlechip with the model number of ATMEGA8A is used as a first ADC pin;

the ADC1 pin of the single chip microcomputer with the model number of ATMEGA8A is used as a second ADC pin;

an ADC2 pin of a singlechip with the model number of ATMEGA8A is used as a third ADC pin;

and a PB0 pin of the singlechip with the model number of ATMEGA8A is used as a control pin.

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