This immobilizer circuit for vehicles was found in a 80’s Hands On Electronics. The circuit shortens the platinum to prevent its operation and thus the operation of the engine when started.
This circuit produces the sound of percussion such as blocks, drum, bell, etc. The frequency...
We found this oscillator in a publication from the 1960s. The frequency is around 600 Hz with the...
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...