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U.S. Senate Custom Electronics

1995 (David Carroll Electronics, Inc.)

The Senate Job required tons of custom stuff in order to support what was at the time a highly advanced, one of a kind system. One of the design challenges was that the control room was about 450 feet away from the chamber as the rat crawls. The Desk Units required power, but it was impossible to locate power supplies close to the chamber. They had to go in the control room.

We won the job partially by being so bold as to suggest phantom powering the desk units. This would eliminate a massive wiring job to bring the DC power to the desk units (approximately 30W each). Instead it created a massive custom design and fabrication job for us. All of the hardware on this page was designed and built in house.

	The Gallery monitor panel. Provided audio monitoring selection and aux control functions at the operator's control position.		Power Distribution Unit. This unit combines the incoming power from six 1KW power supplies and distributes to the powered patchbays.
	One of the many various tie panels we built for the job. the AES signal is carried on LEMO connectors throughout.		Front of PDU. Each distribution output is individually fused. Metering is provided to check voltage and current sharing of each PSU.
	One of the configuration patchbays.		One of six 1KW, 120VDC unregulated power supply units. Each one load shares through shottky diodes in the PDU.
	Another type of configuration patch bays.		Powered Patchbay. This is where the 120V is injected in common mode (phantom) onto the AES digital audio signal, through custom wound transformers. Each Desk unit is fused here with an indicating fuse.
	A redundant power supply to supply power to the redundancy relays.		One of the Redundancy Relay units. The digital output of the (redundant) central Media Matrix (two units) was routed through this 2-input (for redundancy) relay unit so that the ENTIRE mediamatrix could be hot-swapped at the push of a button. As far as I know that has only happened twice, and it was operator error both times.
	The original operator's control console. We did the electronics for this one.		Close up of Redundancy Relay, made twice for redundancy. In case you didn't get it the first time.