The purpose of this circuit is to check the linearity of SSB amplifiers. The circuit was found in an old documentation for hams. The diode is a general purpose detector type.
The operational amplifier used in this configuration is uncommon today, but more modern types can...
This circuit triggers some load such as a lamp, video camera and monitor when someone rings the...
This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be...