Their rival at the time was Touch Plate. Those are also still in production.
Yes, as I understand it, the main difference is that the Touch Plate system uses relays with a single coil and a ratcheting mechanism, which alternates ON/OFF with each control pulse. This allows the use of two-wire control circuits. I think there's another, newer system which uses DC of opposite polarities to control ON or OFF; I believe it uses Panasonic relays.
What this pic does not show is the multiple master switching plates made for these systems.
Typically, one would be at the master bedroom, and another at the kitchen. These would have LV links duplicating the trigger function of each control solenoid. So one could sit at the bedside and fire off lights all over the home -- or turn them off, too.
There's one here: GE master switch
and a neat ad: GE master switch ad
also, a photo of the wiring behind one: GE master switch wiring
It is NOT true that the lock-up of a plate-switch would jamb the entire system. Such lock-ups merely zap one solenoid at a time. Stuck contacts then leave the solenoid unable to change state/ switch.
Right - from what I've read here and elsewhere, that seems to be the system's most common failure mode. My PLC-based system concept would eliminate that problem - replacing it with the risk of PLC hardware or programmer (me) failure!
Left on -- these solenoids then have power draining impacts on nearby solenoids -- making them iffy.
Todays IR guns can spot the locked up solenoid in a jiffy -- which can then be disconnected on the LV side. Thusly, the drain is gone.
Then it's a matter of finding out which wall-plate switch is stuck in a closed state.
Great troubleshooting idea!
Now, in keeping with the 1960s theme, we need to house an IR gun in a case that looks and sounds like the original Star Trek "tricorder".
Since these systems are fossils -- switch failures are to be expected. Conventional switches would've been long since replaced.
BTW, these systems are also compatible with placing the solenoids all over the home -- with the full voltage conductors being switched at or near the light fixtures.
From such locations, a multi-wire LV harness/ cable assembly would weave around the rafters on back to central control points.
The result, either style, is to have 3-way and 4-way switching all over the home -- with master switching to boot.
Yes, you could install the relays in a KO in the fixture box. I never cared for that concept because of the difficultly accessing the relays; the centralized relay boxes seem like a better approach. Also, I like to have the low-voltage connections enclosed in a box rather than just hanging inside the wall or ceiling.
A member of the GE low-voltage Yahoo group
came up with a really good idea for installing a one or two relays: he mounts two 4-11/16 x 2-1/8 boxes about an inch apart, and inserts the relay from inside one box into the opposite KO on the other box, so the line-voltage "head" is in one box, and the control wires are in the other. Makes for a neat installation, and is a lot cheaper than the GE relay tubs.
I'm considering a "box within a box" approach for mounting larger numbers of relays. I'd install the relays in KOs along the sides of a 4" deep pull box (maybe 8x8 or 10x10), with the control wires inside the box. Then I'd put that box inside a larger, 6" deep box (maybe the kind with a hinged cover and back panel), and use the space between the two boxes for the line-voltage wiring, with DIN-rail terminal blocks for the neutral and equipment-gound connection. A conduit nipple would bring the control wires from inside the smaller box through the side of the larger box.
Today X-10 and others have passed this approach by.
Yes, wireless RF controls are the big thing today.
IIRC the GE solenoids even have a motor rating -- it's not big, but it's there.
Right again - it's 1/2HP at 110-125VAC, and 1-1/2HP at 22-277VAC. Also a 20A tungsten rating at 125VAC, and 20A ballast rating at 277VAC.