We found this circuit in a 1976 publication. The transistors can be BC547 or 2N2222. Crystals up to a few tens of Megahertz can be tested. The LED can be of any type. The capacitors must all be ceramic.
Found in an Electronic Engineering from the 80's, this circuit makes use of components of the...
This limit detector or window discriminator uses an old operational amplifier, but it can be...
January 2017 - The new Texas Instruments LPV801 and LPV802 amps available at Mouser Electronics consume...