TE Revolution components Overview: The Revolution system has many add-on boards, and a number of revisions of them. I've decided to make a separate page for them for organizational purposes. Note that some of these may no longer be available. 57073 - Smoke control board I believe there are 2 relays on the opposite side, you can control 2 higher current devices (contacts rated 2.5 amps) 57076 -Capacitor bank The original 57076 capacitor bank had 6 capacitors on it, as Crest was learning about how glitches in power were affecting the Revolution. It had 6 2,200mfd caps, for 13,200 mfd at 35v. I don't think this one is available any longer. In 2017, I have found this one: Listed as 57077, but the picture name is 57007. It has 3 3,300mfd caps for a total of 9,900mfd at 25v This connects to 2 pins on the underside of the on board unit, and you can daisy-chain these cap boards if necessary. I question the 25 volt rating, good engineering practics is rating at double the working voltage to be safe with electrolytics. These should be at least 35 volt if not 50 volt for operation at 24 volts. At one time the system came with a single cap board. Note this cap is blown, and the voltage rating is 25 volts. I repeat that you should not use this anywhere near 24 volts. 57077 - "Non-plug-and-play" socket There are a number of "sockets" available. Top right is the original board, with the fuses and diodes and screw terminals for the track/power, and the headlights. The diodes are still there. This board properly supports the decoder at both ends. The part number is CRE57077 Top left is the socket supplied with the original Revolution "kit". It only connects to the 12 pin end of the board, and it has 2 fuses and 2 small diodes. The diodes are there to allow the headlight outputs to work. This is labeled UEXT-02 (v1.1). Paul Norton reports a version UEXT-10 V1.3 has the diodes by the fuses. (is this a typo and is UEXT-01?) The original adapter board with 7 wires and no fuses was labeled UEXT-01. Apparently there is a new "half board" supplied with the system that has screw terminals, and the center terminals are so small they only accomodate one wire, a problem with some installations that have additional components. The later 7-screw terminal adapter CON1 also has the diodes behind the 12-position socket. 57078 - "Non-plug-and-play" socket Note: there have been several versions of this board. Bottom right is the board that allows any polarity to be input, (as in track power), so it has 4 large diodes for a full wave bridge and 2 capacitors to reduce the glitches prevalent in the Revolution upon short power interruptions. The part number is CRE57078. (Photo courtesy of Dave Bodnar) 2017 model below. No more diodes or fuses or filter caps. Use this for locos that don't have the Aristo socket: I cannot tell the right part number for the above, in 2017 it is on the Precision RC site as 57078, but the picture below shows what looks to be the same thing, and you can see the part number is 57077: 57079 - "active linear plug and play board" In 2017 a new socket for the on board decoders was made available, with filtering to produce "linear" instead of PWM output, as well as diodes to rectify input voltage to a constant polarity and includes a socket too. You can use this as a standalone full wave bridge and PWM filter for other applications G SCale Graphics offers a PWM to Linear converter: Note: the Crest CRE-57079 was a full wave bridge rectifier, used to ensure proper polarity to the Revo when running from track power. 57080 - 500ma PWC (PWM) to Linear 1/2 amp converter to give you smooth DC (linear) from PWM (PWC if you speak ancient Aristo) Yes, I know they still call Pulse Width Modulation Pulse Width Control - no one else calls PWM anything but PWM. Not really sure under what conditions you would use this. 57090 - Smoke board, plug and play board and wires 1x Basic Plug & Play Board1x 1A Smoke Control Board1x 3pin Wire connector1x Set Push-Switch1x 7pin Wire connector1x Speaker wire onnector 57091 / 57091A PWC (PWM) to Linear converter This device is basically a filter with 2 capacitors and an inductor to "smooth out" the Pulse Width Modulated output (which for some reason is called Pulse Width Control) to something closer to straight DC. This is necessary for some sound systems that interpret ANY PWC output as full speed, and also for lighting circuits that use regulators that become "confused" with the pulsating power, typically USA Trains, and some of the early Aristo units with a microprocessor acting as a voltage regulator. Also Aristo smoke units can have this same issue sometimes (not always) The original 57091 has 2 input terminals and 2 output terminals: The unit shown on the Precision RC site differs with 3 terminals as input: (but I cannot figure why, maybe like the new super receiver, the center terminal is not connected.) There are also 2 diodes on this board, you can just see one of them behind the nearest cap. For the CRE-57091A with the diodes, here is the schematic: So the middle terminal maybe could be used to bleed off power at some point? Maybe when the system is shut off, to discharge the caps? 57103 - fan for super receivers Note: this is a 24v dc fan.