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Here are some picture of my TC controller. I do not include a schematic, as my arrangement was forced upon me due to the financial necessity of using what parts I had and could scrounge and is not ideal. But this controller cost me less than $50 US!! Basically, I didn't have any switches capable of handling the load, so I had to use the ice cube style relays for each switch, making for a complicated wiring diagram.

The PSU is controlled by the left variac, a 20 amp Powerstat. The SG vacuum motor is controlled by the 4.5 amp variac on the right, also a Powerstat. The red button is the momentary primary circuit activator, and the key switch on the left is for continuous mode. The key on the right is the main power switch. One green indicator shows when the unit is plugged in and the other shows power on. Yellow indicators show when power is available to the variacs. The hour meter tracks the PSU variac. The ammeter is connected so as to show total system draw, and the voltmeter can display mains voltage or the output voltage of either variac with the small on/on/on switch located to it's left. I really like this feature. The fuses on the left are for the variacs, and there is a 25 amp circuit breaker inside, not visible in the pictures. The switch on the left of the hour meter enables/disables the PFC (power factor correction) capacitors.

There are RFI filters on both variac outputs, and if you look closely at the second picture you will see MOVs (metal oxide varistors) sprinkled throughout the system to ground any excessive voltages. The PFC caps are 6 multiple value 36/20uf motor run types, which is very cool as I can range my PFC values from 3uf to 336uf by changing the jumper wires. The switch controlling the PFC is there for testing different values on different loads, and so I can use the controller on other projects where PFC caps are undesirable.

The entire mess is enclosed in an ammunition box, courtesy of Uncle Sam. The crossbar was welded on and removing it would have been a mess. Still, good boxes are hard to come by, and it does have really nice handles and lid. Cooling is performed by a 110V muffin fan, and the intake is positioned so as to pull the moving air through the variacs, which generate the most heat.