Found in a 90s Popular Electronics, this circuit makes use of power MOSFETs. Equivalent MOSFETs can be used. The circuit acts as a shield.
This circuit was found in a Radio Escuela Gráfica magazine from Argentina published in the 70's....
This detector uses an unusual sensor today. The circuit is from an 80s documentation. Its...
This interesting configuration uses two speakers as a load to have a push-pull excitation with...