HIRES CCD Controller Electronics

This section contains descriptions of the overall electronics for the HIRES CCD controller.

Footlocker Fan Control, EL-3416

Schematic: schematics/fans.sch.pdf
Page last updated: August 2, 2004

The footlocker cooling system consists of a heat exchanger, two 110V AC fans, and a solid state relay located in the FLIC box. The heat exchanger is plumbed into the observatory coolant system with sealing quick disconnect fittings. Current is supplied to the AC fans by way of a Crydom D1225 solid state relay. The relay is mounted on a general purpose relay card. For this application, the plus terminal of the relay is jumpered to +5V and the signal is applied to the negative terminal. When the controller pulls the fans signal low, the relay turns on and the fans turn on. The left side of the drawing shows that the signal from the controller is routed through the Utility Support board and the Utility Support Daughter board as Dout14. The following table gives the signal path of the fan control signal: