This circuit from a Popular Electronics from the 90s uses a common optocoupler and a general-purpose transistor to control a sensitive relay that can be from 6 to 12 V.
This mechanical reverberator circuit for guitar was found in the February 1970 issue of Radio...
This circuit generates high pulses from a sinusoidal input, using SCRs for this purpose. The...
September 2016 - It can be purchased from Mouser Electronics the new ultraviolet high power LEDs...