This circuit is from a 1980's documentation for telecommunications. The circuit is used in SSB and the diodes must be suitable types for the application. The audio input is low impedance.
This old configuration, using a unijunction transistor (UJT) controls a LED than blinks if an...
This circuit for loads up to 10 A was found in a 2005 Linear Technology documentation. The MOSFET...
circuit is used to increase the sensivity of a relay. A 50 to 100 mA relay can be triggered with...