|Re: HP67 doesn't turn on without battery pack?|
Message #12 Posted by Michael de Estrada on 7 Nov 2009, 5:28 p.m.,
in response to message #9 by Vieira, Luiz C. (Brazil)
I have copied the following information from the MoHPC:
Classics (HP-35, 45, 55, 65, 67, 80)
Battery HP 82001B, Chargers HP 00035-60008, HP 03502A, HP 82001A/B, HP 82002A/B/C, HP 82010A (120/240 VAC), HP 82022A(240 VAC), HP 82011A (240 VAC)
Topcat (HP-91, 92, 95C, 97, 97S)
Battery HP 82033A, Chargers HP 82040A, HP 82059A/B/C/D, (HP 82032, 82066B, 82068B 240 VAC only)
As you can see the HP-67 and HP-55 use the same type of external power unit, as I have described. Since the HP-55 does not have card reader circuitry, it is safe to operate it off the external adapter without there being a battery inside. However, as stated by Randy, damaged is possible to the card reader circuitry, even if it is not operating.
The HP-97 uses a totally different power unit, which outputs ~12 Vac no load on a single circuit (it is rated 8 Vac, 3W). This is a similar situation to Spices and Woodstocks, where power signal rectification and regulation occurs inside the calculator and which require that a good battery be present when operating the calculator. Basically, this type of power unit should be used as a battery charger only, and should not be considered an external adapter for operating the calculator in lieu of batteries. In fact the Owner's Handbook for the HP-97 states that "Even though you are using the adapter/charger, the batteries must remain in the calculator whenever the calculator is used - Note: Attempting to operate the HP-97 from the ac line with the battery pack removed may result in wrong or improper displays."