This circuit for currents from 500 mA to 1.5 A was found on a Ham Radio from the 90s. R4 determines the current in the load under test. Transistors must be equipped with radiators.
This circuit is from a Popular Electronics from the 90s. The integrated circuit admits equivalents...
This very interesting project was obtained in a 1980 publication. It consists of a device that is...
This circuit beeps when the sensor is triggered by the opening of the freezer door or other...