I. Working principle of Hall electronic ignition system Shanghai Santana car adopts Holly contactless electronic ignition system, which consists of distributor, signal generator, igniter, high-energy ignition coil, high-voltage line and spark plug. The Hall signal generator is made according to the principle of Hall effect, and it is installed in the distributor. Hall signal generator is composed of trigger impeller 1 and Hall sensor 4. Like the traditional distributor cam, the trigger impeller is sleeved on the upper part of the distributor shaft. It can rotate together with the distributor shaft and make a small amount of rotation relative to the distributor shaft to ensure the normal work of the centrifugal regulating device. The number of blades of the trigger impeller is equal to the number of cylinders, the upper part of the trigger impeller is sheathed with a distributor, and the distributor rotates with the trigger impeller. The Hall sensor 4 consists of a permanent magnet 3 with a guide plate (magnetic conduction) and a Hall integrated block 2, and triggers the blades of the impeller 1 to rotate between the Hall integrated block 2 and the permanent magnet 3. The Hall integrated block 2 includes a Hall element and an integrated circuit. When the Hall signal generator works, the Hall voltage Uh generated by the Hall element is mV level, and the signal is very weak, so it needs to be processed. This task is accomplished by integrated circuit, so that the Hall voltage Uh signal generated by Hall element will be amplified and pulse-shaped, and finally output as a neat rectangular pulse (square wave) signal Ug. Hall signal generator is an active device, which needs power supply to work. The power supply of Hall integrated block is provided by igniter. The collector of the output electrode of Hall integrated circuit is in the form of open circuit output, and the load resistance of the collector is set in the igniter. The Hall signal generator has three wires connected to the igniter, one is the power input wire (red and black wire), the other is the signal output wire (green and white wire) and the other is the ground wire (brown and white wire). The three-wire sockets in the housing of 9J Hall signal generator are marked with "+","0" and "-"symbols respectively. When the distributor works, the blades rotate with the distributor shaft. Whenever the blade enters the air gap between the permanent magnet and the Hall element, the magnetic field in the Hall integrated block is bypassed (or magnetically isolated) by the blade of the impeller. At this time, the Hall element does not generate Hall voltage, the triode of the output electrode of the integrated circuit is in the off state, and the signal generator outputs high potential. When the blade of the trigger impeller leaves the air gap, the magnetic relaxation of the permanent magnet forms a loop through the Hall integrated block and the guide plate. At this time, the Hall element generates a Hall voltage, the triode of the output electrode of the integrated circuit is in a conducting state, and the signal generator outputs a low potential. The distributor shaft rotates once and outputs four square waves. From top to bottom, the rotation direction of the trigger impeller is clockwise. When the trailing edge of the impeller slot rotates so that the end face of the magnetic pole is only half exposed, the voltage at the signal output terminal instantly jumps from low potential to high potential, which is the ignition time. The Hall igniter is connected with the signal generator through a two-wire plug. When the signal output terminal inputs the signal into the ignition controller, it controls a high-power triode after being processed by its internal circuit, and then controls the ignition coil, so that the high-voltage output terminal of the ignition coil outputs a high-voltage pulse to ignite the spark plug. Hall igniter is essentially an electronic switch, which is controlled by the signal voltage generated by Hall sensor. The ignition controller also has the function of automatic power-off when stopping to protect the ignition coil from being burned out. In addition, the ignition controller also has the function of current limiting control. When it is detected that the current value in the ignition coil is less than 94% of the rated value, the control circuit increases the rising rate of the current before the input signal is converted to a low level to ensure that the primary coil generates sufficient magnetism. The closing angle control function can continuously adjust the closing angle according to the working speed of the engine, the power supply voltage and the performance of the ignition coil, so that the on-time of the primary circuit remains basically unchanged within the working speed range of the engine, so that the engine has enough ignition energy and ignition voltage at high speed, and no flameout will occur; At low speed, the service life of ignition coil and ignition electronic components will not be affected by overheating. Compared with magnetic induction electronic ignition device, Hall electronic ignition device can output stable ignition signal even when the engine speed is very low, because the amplitude waveform of the ignition signal output by its ignition signal generator is not affected by the engine speed, so it has good low-speed performance and is beneficial to the engine starting. Moreover, the Hall ignition signal generator can output a square wave signal with a certain high-low level time ratio under any working conditions, so the ignition timing is accurate and easy to control. In addition, the Hall ignition signal generator does not need to be adjusted and is not affected by dust and oil pollution, which makes the Hall electronic ignition device more reliable in working performance and longer in service life. 2. Fault detection method of Hall electronic ignition system Taking Santana car as an example, the fault detection method and steps of Hall contactless electronic ignition system are explained. 1. If the ignition system is suspected to be faulty, pull out the high-voltage line in the center of the distributor so that its end is 5-7 mm away from the cylinder block, turn on the ignition switch, start the engine, and observe whether the end of the high-voltage line flashes. If there is no strong spark, the ignition system is faulty. Correctly checking the parts and connecting wires of the ignition system is the key to troubleshooting the ignition system. 2. Check the ignition coil, high voltage line and distributor, and measure the resistance values of the primary and secondary windings of the ignition coil. Before measurement, turn off the ignition switch and remove the wires on the ignition coil. The resistance value of the primary winding, that is, the resistance value between "+"(or "15") and "-"(or "1") of the ignition coil should be 0.52-0.76 ohm; The resistance value of the secondary winding, that is, the resistance value between the ignition coil "-"(or "1") and the high-voltage socket, should be 2.4-3.5kohm.. If the resistance value meets the requirements, the ignition coil is in good condition and all the wires on the ignition coil should be installed. The resistance value of each high-voltage line should be around 1 kiloohm, and the resistance value of the distributor should be around 1 kiloohm. 3. Inspection of the igniter ① Confirm whether the power supply circuit of the igniter is normal: turn off the ignition switch, unplug the igniter connector, connect the two contact pins of the multimeter (voltage gear) to the terminals 4 and 2 of the wiring harness plug, and turn on the ignition switch. The voltage measured by voltmeter should be about the battery voltage, otherwise, find out the open circuit fault of power supply and eliminate it. ② Confirm the performance of the igniter: turn off the ignition switch, connect the igniter connector, unplug the connector of the distributor Hall signal generator, and connect the two pins of the voltmeter to the 15(+) and 1(-) terminals of the ignition coil. When the ignition switch is turned on, the voltage value of the voltmeter should be 2-6V, and it will drop to zero after 1-2, otherwise the igniter should be replaced. ③ Confirm whether the output voltage from the igniter to the Hall signal generator is normal: Turn off the ignition switch and connect the two pins of the voltmeter to the "+"and "-"terminals of the harness plug of the Hall signal generator. When the ignition switch is turned on; The voltage measured by voltmeter should be 5-11v. If it is less than 5V or 0V, test terminals 5 and 3 of igniter plug-in in the same way. If the voltage value is greater than 5V, it means that there is an open circuit fault in the wiring harness between the igniter and the signal generator, which should be eliminated. If the voltage value is also lower than 5V, replace the igniter. ④ Check the igniter with bypass signal generator: turn off the ignition switch and unplug the central high-voltage line on the distributor cover so that its end is 5-7 mm away from the cylinder block. Unplug the harness connector of the distributor signal generator, and use a jumper wire to connect one end with the signal wire plug, while the other end is temporarily suspended. Turn on the ignition switch and repeatedly ground the suspended end of the jumper wire; At this time, observe whether there is jumping at the end of the central high-voltage line. If there is, it means that the firearms are in good condition and working normally. If the ignition coil and connecting wire are normal, there is something wrong with the igniter. 4. Inspection of Hall signal generator In order to eliminate interference factors, this item should generally be carried out on the basis of normal inspection of ignition coil and igniter connecting wire. The method is as follows: measure the output voltage of the signal generator, turn off the ignition switch, open the distributor cover, pull out the central high-voltage line on the distributor cover and ground it, and connect the two contact pins of the voltmeter to the signal output line (0) and the grounding line (-) of the closed connector respectively, and the lead colors are green and white lines and brown and white lines. Then rotate the engine according to the rotating direction of the engine, and observe the reading of the voltmeter, which generally changes between 0 and 9 V. When the distributor triggers the impeller blade in the air gap, its voltage value is 2-9V, and when the impeller blade is not in the air gap, its voltage value is about 0.3-0.4V V. If the voltage value does not change between 0 and 0-9v, the Hall signal generator should be replaced. The voltage value displayed by the voltmeter mentioned above is different due to different production years and different internal circuit parameters, so it should be compared with the cars produced in the same period during the test.