This circuit is from the Motorola Linear Databook of 1990 and can be implemented with other operational amplifiers. The power supply must be symmetrical.
The gates of a 4093 can be used form a two-tone siren as shown in the configuration of Figure. The...
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...
This simple circuit controls the brightness of an LED from LDRs, NTCs, PTCs or other resistive sensors....