PC-100 US Version

[Duane Hess]

*** Edited as prematurely posted somehow.

Measured the voltages across my transformer and they agree with Maximilian's and the ti58c.phweb.me schematics:
- Red-Yellow 23.5 VAC
- Green-Blue 9.2 VAC
This certainly implies if you can get a transformer that matches the power and voltage ratios you should be good. Tried to measure the ohms across all the coils, but my meter is screwy.

The transformer is marked:
1014877-2
TEX TRANS
1181 7827

Attached a couple pictures. They are poor; only have my flip phone and cannot hold my hands still. However, they show the transformer has only the number of taps needed. I took it out and all non-shown sides are plain other than the markings above were stamped on one side. The circuit board is quite blurry, but it shows the unit closely matches any pictures I've seen on the web. i.e. the 100B & C are very similar if not identical in overall layout.

Its very hard to see in my pic, but from what shows in Maximilian's photo does match my unit. Except the big CAP in the lower right of his picture is orange, where mine is dark blue, color differences in some other items and a very small ceramic capacitor directly right of the printer motor cable.

datamath.org seems to indicate the B&C models are very similar. Where the original PC-100 (no suffix) and A likely have pertinent circuit board differences due to different calc model support.

My 100C is marked at 120VAC and 0.35A.

The various PC-100 models supports different calcs, but seem to have the same printer (judging from pictures). Also, all the different calcs supported between the various PC-100s use the same battery pack, but some have different power adapters (output voltages and amps). So, the original 100 or 100A might have different transformer values for the spare battery charing compartment. (personally doubt it)

From datamath.org its hard to tell if earlier PC-100 support for various calcs was in terms of how it communicates with the calculator or had different power for charging the batteries. Would make sense it was for communications differences, as they all use the same battery pack (BP-1A).

You'd assume since the various calc models take the same battery pack, PC-100 powering the attached calculator and printer circuits should be the same. i.e. older calcs had different power adapters, but might simply be an "age revision level thing" of plug and charging circuits, but internally all operated at the same levels?

Just my guessing.