PC-100 US Version

[Duane Hess]

Been absent in the hospital for a while. Various posts have made the physical differences clear. I have nothing real to contribute.

But:
1. I'm retired and bored.
2. Also a bit of a busy body, if not fuss-budget.
so, wanted to make a comment. Should you convert the unit to 220V, do not throw the USA socket/cord away. The specific USA connector/cord you have is somewhat rare here. Many devices older than the PC-100 use the same connection and collectors may be interested in the cord and device socket. For example, some very late 60's/early 70's USA Monroe devices have that connection.

My 100 does not have a detachable cord. However the grounding does match your unit. The ground wire goes to the transformer frame. In all units the transformer is mounted via plastic support points. So, the ground attachment appears to be simply for plug compatibility. Certainly, attaching ground to the frame isn't bad. Hence, changing the power cord and plug on your 100A should not affect device reliability or safety.

The picture Maximilian showed at http://www.vintage-calculators.nl/P1000679as.jpg clearly is a 2 wire connection and no ground.

The 220V and 120V pictures show removable power cord units. It seems the plug is held in place via shield which is screwed down. Hence, replacement obviously looks feasible.

The real concern is not to forget insulation. Swapping the socket/cord and transformer to 220 should warrant swapping the socket to transformer wires. And possibly the fuse holder. The plug to transformer wires are sheathed together in one and cable tied together in the other unit. There is a real concern reusing the 120V wires may result in insulation breakdown (arcing) or heating if used with 220V.

I have various 120-220V and 120-100V (Japan) tranformers for my stuff. And I've had your feelings many times. Much easier if I could simply convert the unit. Especially since numerous detachable cord units of mine have USA looking sockets. An accident waiting to happen!

My 2 cents, for whatever its worth.