This circuit makes use of a stroboscopic tube, a component that no longer exists today. The circuit is from the 70's and can be adapted to use mains voltage.
This circuit produces the ticking of a clock on a common piezoelectric transducer. The circuit has an...
The basis of this circuit is a double T in the feedback, which has the components calculated to...
This configuration was found in the Texas Instruments optoelectronics manual. PNP transistors...