HP charger 82002c for handheld calculators



#4

I was gifted with a box of small transformers and among them was a 82002C charger which can be used with the HP-35, 45, etc. This has a 3 pin output and meters a nominal 5 VDC between center and right pin and nominal -17 VDC from center to left pin. The 5 volt side makes sense but is the other voltage an indication of a bad circuit? The label says that the output is 50 MA at 4.2 VDC and 150 MA at 4 VDC. Obviously I'm in over my head here, so any thoughts would be appreciated. I'm only pursuing this because these things seem to have some value. Thanks, Dave


#5

Quote:
This has a 3 pin output and meters a nominal 5 VDC between center and right pin and nominal -17 VDC from center to left pin. The 5 volt side makes sense but is the other voltage an indication of a bad circuit?

Please take a look at HP Battery Information, in this museum.

Quoting from the linked page:

"The battery charger circuit is current limited and will typically read much higher than 4.2 V without a load."

HTH

Gerson

P.S.:
Classic Charger Schematic


Edited: 19 May 2013, 2:14 a.m.


#6

Thank you Gerson, I didn't expect such an on-spot answer. It looked like those paragraphs were written just for me. Much appreciated!

(BTW, I fathered only girls, but had considered that if I had a son I might have named him either Gerson or Thurston. I thought Gerson Burson would have a memorable ring.)

Best regards,
Dave


Possibly Related Threads…
Thread Author Replies Views Last Post
  HP-67 charger Marcel Samek 3 1,818 11-22-2013, 10:45 PM
Last Post: Marcel Samek
  Classic (HP-67) charger issues revisited Matt Agajanian 6 2,440 05-20-2012, 10:50 PM
Last Post: Matt Agajanian
  HP-35 Charger/Adapter Repair (82002C) LHH 0 1,010 05-19-2012, 01:21 AM
Last Post: LHH
  HP-67 wall charger Wytnucls 2 1,404 04-19-2012, 10:13 PM
Last Post: Dan W
  HP 97 charger Harald 2 1,317 03-30-2012, 02:01 PM
Last Post: Harald
  Which charger for a35 Matt Agajanian 3 1,564 03-23-2012, 02:58 AM
Last Post: Marcus von Cube, Germany
  Aristo M85 -- What charger? Gene Wright 9 2,957 11-03-2011, 04:56 PM
Last Post: Mike (Austria)
  HP97 charger Olivier De Smet 5 1,910 09-20-2011, 06:53 AM
Last Post: Paul Berger (Canada)
  Your opinion about this custom USB charger for vintage Calculators Namir 3 1,464 08-10-2011, 09:56 PM
Last Post: BobVA
  HP-67 AC Charger Ángel Martin 6 2,288 06-25-2011, 07:31 PM
Last Post: Trent Moseley

Forum Jump: