4/23/17 Testing Card Components

Built, tested and installed remaining LED Driver cards. Tested transistors before installing, but still found 2 dead ones during card testing. Also found 1 weak transistor for the red LED Driver card. Out comes the desoldering braid!

This is not really a surprise because I don’t know the history of these transistors. They could have been used in the original simulator project back in 1984. I’m still using wire from a telephone cable bundle I got back in 1981!

Changing lights in Annunciator box from yellow/red to clear. Those lights should arrive Wednesday. This should increase brightness. Thinking about keeping the red light for Rx Trip. Maybe try two lights. Will check combined current to see if the transistor can handle. The specs said 800 mA for the collector, but 1.2 W total dissipation.

(Update: Nope – cannot drive two lights. Transistor started getting too warm so I stopped the test)

Got a fuse block for power going to the sim box.
1. Annunciator Power (7A)
2. Status Lights (TBD)
3. Rotary Controls (TBD – probably 0.5A)
4. Switches (TBD – probably 0.5A)

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