This circuit is from old documentation, using a component that cannot be found easily today. The indicator is a galvanometer, and the input voltage is in the order of 1 V.
This charger was found in an old Motorola manual using an SCR from this company, which, however, can...
This circuit visually indicates that a high voltage is present in an outlet or other point. The...
This simple circuit of effects is interspersed between the instrument and the amplifier. It is...