The simulator is designed to test automotive electronic switches ignition system oscillographic method. To check the switch on it the entry must be submitted rectangular pulses with a duty cycle of about three and a repetition rate of 33 or 100 Hz. This corresponds to the rotation of the crankshaft four-cylinder engine with a frequency of 500 and 1500 rpm.
Depending on shaft speed duty cycle output the switch must change.
Many hams got oscilloscopes, but not all are the necessary generators. In the proposed device is rectangular pulses generated by the multivibrator transistors VT1 and VT2, which is coming to key - transistor VT3. The collector VT3 simulator connect to pin 7G switch. Instead of the ignition coil as the load can be connected automotive lamp A12-45+40 (EL1) or close to them in power. Frequency generator set switch SA1.
To detect faults in the switch can, comparing waveforms voltages at the test points of the circuit "securitycoverage" switch serviceable.
Using the button SB1 is checked off of the current through the ignition coil when the engine stop. When the button is pressed the lamp after a few seconds have from going out.
Author: P. Sevastyanov, Tashkent, Uzbekistan