Automobile ignition system circuit diagram

Characteristics of Automobile Ignition System

Increase primary current, increase secondary voltage and ignition energy, improve high-speed performance. Reduce contact sparks, extend contact life, and overcome various defects caused by mechanical contacts. Easy maintenance, good starting performance. The mixture burns completely and emits less pollutants. It is conducive to the development of automobiles towards multi-cylinder and high-speed directions.

The function of automobile ignition system

1. The ignition system converts the low voltage of the power supply into a high voltage, and then sends it to each cylinder in turn according to the engine ignition sequence to ignite the compressed mixture;

2. It can adapt to changes in engine operating conditions and usage conditions, automatically adjust the ignition timing, and achieve reliable and accurate ignition;

3. Manually calibrate the ignition timing when replacing fuel or installing a distributor.

Automobile ignition system circuit diagram (I)

The circuit diagram of the Hall type electronic ignition device is shown in the figure.

Figure 1. Hall type electronic ignition device circuit diagram

Schematic diagram of electronic ignition device: The Hall-type electronic ignition device uses an integrated circuit ignition device with functions such as current limiting, ignition angle control, parking power-off protection, and closing angle control. The circuit is shown in the figure.

Figure 1. Circuit diagram of integrated circuit ignition device

Working principle: Turn on the ignition switch, the engine rotates, and the Hall signal generator in the distributor triggers the blades of the impeller, which periodically passes through the air gap of the sensor. When the blade enters the air gap, the magnetic field on the Hall element is shielded, and no Hall voltage is generated. The signal voltage output by the Hall signal generator is high voltage. The signal enters the igniter through the igniter sockets ⑥ and ③, and the high-power triode VT is turned on through the internal circuit of the igniter, connecting the primary circuit. Its circuit is: battery "+" → ignition switch → primary winding of ignition coil → igniter high-power tube → ground → battery "-" pole. When the impeller is triggered to leave the air gap, the magnetic field is added to the Hall element, generating Hall voltage, the signal generator outputs low voltage, the igniter high-power tube VT is cut off, the primary circuit is cut off, the secondary generates high voltage, sparks through the spark plug, and ignites the mixture.

Automobile ignition system circuit diagram (II)

Photoelectric electronic ignition device

(1) Signal generator

Structure: The signal generator consists of a signal rotor, a light source and a light receiver, as shown in the figure. The light source is a potassium gallium light emitting diode, which emits an invisible light beam close to the infrared frequency and is concentrated by a hemispherical lens in front of it, limiting the width of the light. A photosensitive diode is used as a light receiver to receive the light emitted by the light emitting diode.

Figure Photoelectric signal generator

Features: The amplitude of the output voltage is not affected by the engine speed and has high reliability.

Working conditions: The signal rotor is driven by the distributor shaft, and the number of blades (light shielding sheets) on it is equal to the number of cylinders in the engine. When the signal rotor rotates with the distributor shaft, the blades and gaps continuously pass between the light source and the photosensitive diode. The photosensitive tube outputs a low level under the illumination of the light source, and outputs a high level in the absence of the light source, thus generating a pulse signal, which is processed by the electronic controller and outputs an ignition signal.

(2) Electronic ignition device

Circuit diagram: The circuit diagram of the photoelectric electronic ignition device is shown in the figure.

Figure 1. Circuit diagram of photoelectric electronic ignition device

Working condition analysis: Gallium arsenic infrared diode GA is the infrared light source, and silicon photosensitive diode VT1 is the receiver. When the engine is working, the shielding disc rotates with the distributor shaft. When the notch on the shielding disc passes through the light source, the infrared light shines on the silicon photosensitive diode VT1 through the notch, turning it on → VT2 on → VT3 on → VT4 off → VT5 on, connecting the primary circuit. When the physical part of the shielding disc blocks the infrared light, VT1 and VT2 are off → VT3 on → VT4 off. The primary circuit is cut off, and high voltage is generated in the secondary.

Precautions for using the ignition system

1. When parking, inspecting or performing necessary disassembly or assembly, turn off the ignition switch first;

2. The battery must be fully charged, and all wires in the ignition system must be well connected, especially the grounding must be in good condition.

3. When replacing ignition system components, generally replace the same model to avoid mixing different models. Do not use ordinary ignition coils to replace special ignition coils.

4. When welding on a vehicle, remove the battery wiring first.

5. When washing the vehicle, avoid splashing water into electronic components.

6. When judging a fault, do not use the spark-scraping method to test the electricity;

7. It is strictly forbidden to remove the battery when the engine is running.

Automobile ignition system circuit diagram (III)

Automobile ignition system designed with CD.

The core of CD4MAX is a self-excited multivibrator composed of Q1 and Q2. The oscillator is used to excite the step-up transformer T1. The output voltage of T1 is rectified by D3-D6 and used to charge the capacitor C4. When the spark plug is closed after charging, a small voltage is sent to the gate of SCR1, which quickly turns on and the charge of C4L is immediately released to the ignition coil. The circuit also includes several optional branches to meet the needs of different types of ignition devices.

X15+ and X15- are used for different starting circuit configurations of non-contact circuit breaker ignition systems. R6 is not used in these systems and can be removed. Depending on the polarity of the sensor, optocoupler U1 (pin 4) can be used in conjunction with X15+.

Please note that the voltage on this system is as high as 60-70kV, so appropriate safety precautions are required.

Automobile ignition system circuit diagram (IV)

The circuit diagram of Epica engine data sensor-ignition system is shown below:

Automobile ignition system circuit diagram (V)

The circuit diagram of Beijing Hyundai Sonata ignition system is shown below: