HP38C Battery Polarity



#5

I have an HP38C which I would like to test using a dc power supply connected directly to the battery pack terminals. Does anyone know which terminal is positive? I assume I'll use a double AA voltage of about 2.8 V to test it.

I'm soon to acquire a 38E. I assume it has the same battery pack situation. Is that true?

Thanks!
Larry


#6

This is from: http://www.hpmuseum.org/batts/battery.htm.

#7

When installing batteries in a Spice series machine, place a strip of ribbon or paper around the pack to make removing it easier. These machines have a tendency for the battery pack to damage the battery contacts when you remove them. One thing that likes to happen is the bottom (free) end of the battery clip snags between the top contact of the battery and the seam around it. When you try to pry the battery out, the clip snaps off. Not helped by the tendency of the batteries to corrode in these machines.

#8

Jim: Thanks for the picture and Web reference. I had looked around the HPMuseum for the polarity info, and somehow overlooked it.

David: Thanks for your tips on 30 series batteries.

The machine worked great when I powered it up.

Larry


Possibly Related Threads…
Thread Author Replies Views Last Post
  Classic battery polarity Kiyoshi Akima 2 1,635 11-08-2013, 01:31 AM
Last Post: Kiyoshi Akima
  Topcat Battery Polarity Les Wright 2 1,407 05-30-2012, 07:23 PM
Last Post: Les Wright
  aOT--Battery/battery contact care advice needed Matt Agajanian 0 1,195 04-24-2012, 07:35 PM
Last Post: Matt Agajanian
  HP-67 - polarity of wires to keyboard/display board? BobVA 6 2,127 05-14-2011, 08:45 AM
Last Post: Randy
  HP38C "6" key repair Peabody 6 1,814 10-28-2009, 06:01 PM
Last Post: Peabody
  TDS 500K dead battery, pictures of the inside of the card and the battery. Geoff Quickfall 4 2,086 04-02-2009, 11:23 PM
Last Post: Geoff Quickfall
  HP 33E Battery Contact Polarity? Danny Eskenazi 8 2,527 05-11-2007, 10:31 AM
Last Post: Danny Eskenazi
  How to halt green corrosion on HP45 copper battery contacts in battery bay? JaSon 1 1,108 07-01-2006, 07:27 AM
Last Post: David Smith
  HP 21 battery door, not battery pack (Sorry for confusion and thanks for advance guidance) raze 0 812 01-23-2004, 01:29 AM
Last Post: raze
  Battery Polarity steve 6 1,707 02-10-2001, 01:20 PM
Last Post: Marx Pio

Forum Jump: