Fan Failure Detect Circuit

This circuit was designed for a Flourescine Angiography Light Box.

Flourescine Angiography is used for the detection of bleeding in the eye.

This Light Box contains a Xenon Lamp that is used to illuminate the inside

of a patients eye.

The Xenon Lamp can overheat without proper cooling.

In this case, the lamp should be turned off and allowed to cool.

One condition that can cause overheating is the failure of the cooling fan.

This circuit is designed to detect such a failure and turn off the Xenon Lamp.

This circuit uses a "Microchip TC-670" chip for failure detection.

	TC670 Data Sheet
PADS Board Layout

This is the original breadboarded circuit

First test with lamp and power supplies

Must have a cover to protect your eyes

First test with a real lightbox

First Prototype Board from ExpressPCB

First professionally made board

Tested and working in the FA Lightbox