This simple circuit uses a car ignition coil. The circuit appeared in the 1983 Radio Electronics Annual Edition. The circuit supports equivalent transistors.
T1 and T2 can be BC557 and T3 a TIP32 for lamps up to 3 A. The supply is made by voltage of 12 V...
This fourth-order filter was found in American documentation from the 90s. The circuit applies to...
This resistance meter uses a two-transistor oscillator as basic configuration. The tone produced...