Battery Charger HP 45/ HP 67

[burkhard]

(06-24-2019 06:50 PM)Carlos CM (Mexico) Wrote:  Does the HP 34c or HP 25 charger work properly for an HP 45 and HP 67? there would be a problem?

Don't try that—it would be "bad".

The Classic series calculators (and I think this includes the 67, even though it's more of a quasi-Classic) expect 4.2 V DC from their charger.

The Woodstock (e.g. HP25) and Spice (e.g. HP34C) chargers put out (rather infamously) ≈10 V AC from their chargers.

So it's AC instead of DC and more than double (!) what it should be.

You need to either
1) Buy an original Classic charger. These are usually cheapest when sold not by themselves, but in conjunction with an beat-up/dead HP-80 or HP-45.
OR
2) Buy one of the USB-based ones for sale on an auction site.
OR
3) Mickey-mouse something together out of parts for other stuff that you can find. Because the plug on the Classic chargers is rather special, this is most of the battle here and I question if it's worth it. I think you would be better off buying a proper one that fits right and spending your hours not re-inventing the wheel.

In any event, don't try to run your calculators on the HP25 or HP34C chargers.

Good luck!