This circuit was found in the May 1984 issue of Radio Electronics magazine. It analyzes the exhaust gases emitted by a car. The circuit uses a special gas sensor from that time.
This circuit also detects IR, providing LED indication. The circuit is used to indicate humidity in...
This circuit uses a JFET, which may be of the type BF244 or BF245 and a PNP bipolar that may be...
This circuit can be used to directly control direct current loads or higher alternating current loads...