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HP34C Repair
04-08-2021, 08:01 AM
Post: #14
RE: HP34C Repair
(04-05-2021 07:53 AM)AndiGer Wrote:  
(04-05-2021 03:37 AM)barry2718 Wrote:  1.The inside of the HP34C also has what appears to be a DC-DC converter (coil transformer, transistor, diodes, resistors capacitors so i am wondering if the 9 Vac input is actually regulated down to 3v to charge and run the microprocessor?

From the Owner's Handbook - page 270:
"Note: Do not attempt to operate the calculator from an ac
line with the battery pack removed."

I think this explains everything
Thank you for this advice, Barry

Barry Moore retired elec. engineer HP Prime, Hp 40, Hp 35S, Hp15c, HP12c, HP34c
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Messages In This Thread
HP34C Repair - javico - 10-29-2018, 07:00 PM
RE: HP34C Repair - burkhard - 10-30-2018, 06:46 AM
RE: HP34C Repair - Steve Simpkin - 10-30-2018, 07:51 AM
RE: HP34C Repair - aurelio - 10-30-2018, 10:55 AM
RE: HP34C Repair - javico - 11-08-2018, 05:38 PM
RE: HP34C Repair - Zaphod - 11-08-2018, 06:03 PM
RE: HP34C Repair - javico - 11-11-2018, 03:36 PM
RE: HP34C Repair - Dieter - 11-11-2018, 04:08 PM
RE: HP34C Repair - DANTONVB - 11-11-2018, 04:55 PM
RE: HP34C Repair - barry2718 - 04-05-2021, 03:37 AM
RE: HP34C Repair - rprosperi - 04-05-2021, 04:05 AM
RE: HP34C Repair - barry2718 - 04-08-2021, 07:59 AM
RE: HP34C Repair - AndiGer - 04-05-2021, 07:53 AM
RE: HP34C Repair - barry2718 - 04-08-2021 08:01 AM



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