I received my annunciator control boards from ExpressPCB.
Here’s a closeup of the driver end of the circuit board. I had to stagger the parts to get everything to fit with enough clearance around all the solder pads.
Just like the Avionics Interconnect circuit from yesterday, I threw a part number and website on these in case I start selling them. I’m definitely selling the other two, so email me if you want one. These can drive up to 10 annunciator lights triggered by either 12V or ground and include a facility for a push to test function and an external dimmer.
Here’s the driver end of a populated board. I don’t have the PCB mount DB-37 connector yet which is why that isn’t present.
Each annunciator light driver has an isolation diode to allow the push to test function. The extra resistor is to protect the diodes against shorting one of the high triggers to ground.
I didn’t forget to attach components here, these are plated through holes that allow these traces to connect to traces on the other side of the board.
Here’s where those traces come through. These route signals to the resistors driving the base of each transistor as well as the collector side of each transistor. The emitters of all transistors are connected together and grounded.
I’m trying to wrap up the tailcone wiring before installing the rear window for good. I fabricated a custom length SkyView network cable to go from the ADAHRS down to the pitch servo. There will be a splitter mounted there that allows the ADAHRS and pitch servo connectors to join to the network cable that will be routed under the floor to the area under the pilot’s seat. To fabricate the splitter, I cut two short sections of SkyView network cable and installed one end of both sets of wires into a single male DB-9 connector. It’s pretty challenging, but you can install two 22AWG wires into a single crimp pin. Getting all of the strands to slide into the pin before crimping is definitely a pain, but is doable.
