Sharp PC-1211, battery question

[Dave Britten]

(04-27-2022 10:56 AM)blackjetrock Wrote:  You can use LR44 batteries in the version of the PC1211 that takes 3 1.5V batteries. This seems to be a version that was sold by Sharp later on. They aren't very common but I do have one.
Alternatively you can maybe rewire the power circuit with a diode to drop the extra voltage. I did this on one of my PC1211s and it seems fine, although I am a bit dubious about the centre tap that the circuit uses. I need to revisit this mod and see if I can improve it.

I wrote it up here:
https://trochilidae.blogspot.com/2016/11...c1211.html

Andrew

That's a good idea, I should probably do that to mine to make sure they're running a bit closer to the original spec. Did you have to cut any traces or remove any components to route through the diode?

EDIT: Okay, I see, seems simple enough. Interestingly, both of mine are different board revisions from yours. One has a diode and resistor already, and the other doesn't have any discrete diodes wired there. Should be the same principle though: just disconnect the red wire and reconnect it with a diode in series.