This dual-operator thermometer circuit was found in the September 1982 issue of Radio Electronics magazine. The sensor consists of a general-purpose transistor.
This conventional astable multivibrator circuit with operational amplifier can be found elsewhere on...
Using red LEDs with ignition voltages of the order of 1.5 V we can make a multiple voltage...
This old circuit (1968) uses a germanium transistor to drive a relazy from a switch. The circuit...