Cradle Electronics

The cradle electronics section of this manual contains descriptions of the cradle electronics for the DEIMOS Spectrograph. It corresponds to the Cradle Electronics tab in the electronics schematics binder.

Cradle Fan Control, EL-3107

Schematic: schematics/VLTFANS.sch.pdf
Page last updated: February 3, 2003

Simplified Drawing

As the diagram above shows, the cooling fans for the DEIMOS electronics cradle enclosure are wired to two Opto-22 relay modules. Each set is wired in parallel and connect to the AC receptacles labeled AC1 and AC2. For diagnostic purposes, the AC cord can be unplugged from the controlled outlet and plugged into any convenient outlet to check for proper operation. Additionally, one of the Opto-22 AC output test relay modules can be substituted for the module in channels 1 or 2 of panel #0 and fan operation can be controlled via the three-position toggle switch atop the module. IMPORTANT: after troubleshooting with the output test module, remember to remove it and reinstall the original module. This is important in that the test module can be set for a manual off state, this would remove software control of the cooling fans and possibly result in overheating of the compartment. Software routines in the Galil controller monitor the compartment temperatures via LM35 solid state sensors. The temperature loop is set to keep the compartments within 5 degrees of 32 degrees F.