This circuit was obtained in a 1969 Mullard manual. The transistors are from that time. The input sensitivity is 300 mV.
This circuit protects galvanometers that are excited by low impedance amplifiers. The circuit is...
This variation of the previous circuit produces a pulsating sound when the sensor is activated. The...
The National Semiconductor LM675 operational amplifier can provide up to 3 A of output current. In the...