This circuit is from an Electronics Now from the 90s. The circuit uses a power integrated circuit from the time that must be equipped with a heatsink. The power supply is 18 V.
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...