This simple 555 component tester was found in the November 1992 issue of Radio Electronics magazine. The circuit is powered by 6 to 12 V batteries.
This circuit was found in Philips documentation from 1967. The phototransistor is from that time,...
We found this third-order Butterworth asymmetric filter in an old manufacturer documentation. The...
We found this circuit in a publication for radio amateurs of 1976. The operational amplifier is a...