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HP Forum Archive 12

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HP-97 Charger Spec
Message #1 Posted by Andy Hall on 11 May 2003, 12:54 p.m.

I recently came upon a HP-97 that is missing it's charger. I would like to improvise a power source so I can determine if the calculator is functional before I try to purchase a charger for it.

Information on this web site says that the HP-97 requires a charger that puts out 8 VAC at 3 VA. On the calculator, near the charger connector, it says "5 VOLTS 2 WATTS".

Comments, explanations, and/or suggestions are welcomed.

Re: HP-97 Charger Spec
Message #2 Posted by David Ramsey on 11 May 2003, 1:00 p.m.,
in response to message #1 by Andy Hall

Well, that agrees with the information printed on my HP-97 and the information printed on the AC adapter it came with. I can't explain the discrepancy.

Re: HP-97 Charger Spec
Message #3 Posted by Vieira, Luiz C. (Brazil) on 11 May 2003, 1:47 p.m.,
in response to message #2 by David Ramsey


there are at least six HP AC adapters compatible with HP97's original. All topcats (HP9x) may use them, also the original HP41 peripheral printer 82143A and some HPIL devices, like the 82161A (tape drive) and 82162A (thermal printer). All of these "guys" are powered by the same battery pack, too.

The three AC adapters I own that can be used with these equipments are:


all of them have the same output connector and they are rated:

3VA ow 3W(82059B

I think the HP97 input specs are for mean average AC input voltage while 8VAC is the AC adapter voltage itself. As I have no HP97 (at least so far), I cannot go any further about the calculator specs.

Hope this helps a bit.

Luiz C. Vieira - Brazil

Re: HP-97 Charger Spec
Message #4 Posted by Jon on 12 May 2003, 3:49 p.m.,
in response to message #3 by Vieira, Luiz C. (Brazil)

If you want to test it, just connect four rechargable batteries (AA is ok) to reach 4.8 to 5.2 volt aprox. Then connect it as you can to battery contacts.

Take care, the "-" is the battery contact closest to the edge of the battery holder.

The charger is 8 Volt because it has to charge 4 batteries 1.2V. Take into consideration that it is AC and the calculator has a diode and a resistor. It is ok. Never use this adapter it without a good battery pack connected. You could damage the calculator because the battery itself guarantees the correct volts. even when charging.

I hope I have helped you



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