We found this circuit in the June 1991 issue of Radio Electronics magazine. The circuit can be used with a resistive sensor or in demonstrations.
This defrost alarm starts from an interesting idea. A small magnet on an ice stone is trapped at the...
This circuit uses one of the first comercial transistor and is from a 1958’s magazine. Tone...
Found in Popular Electronics from the 90s, this circuit powers a warning lamp when the load is...