This section contains descriptions of circuit boards made for use with the Keck ADC project. It corresponds to the Boards tab in the schematics binder.
ADC Relay Driver board, EL-3603
Page last updated: February 11, 2005
The ADC relay driver board is simply a transistor driver for the limit relays. Each circuit has its input wired to an output of one of the various Hall-effect limit sensors. When the drivers input goes high, the transistor supplies the current to drive the associated 24V DC relay.
IMPORTANT NOTE: It is imperative that a 'kickback' diode be wired across the coil of the relay so that the back EMF does not destroy the transistor.
Relay Driver front view
Relay Driver rear view