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Woodstock power supply
01-06-2017, 09:23 AM
Post: #1
Woodstock power supply
Looking at the woodstock schematic:

[Image: HP25_powersupply.gif]

Would it be possible to discard the transformer that comes with these calculators and use the cable and plug to provide a rectified 3v or 3.1v supply instead? I'd like to use mains power for a 20-series device without risking burning it out completely. Is a voltage drop on the supply sufficient? Would I also need current limiting?

My, albeit limited, understanding of circuits indicates that it needs 2.5v at the battery and there is a single diode drop along the way (i.e. -0.6 to -0.7 v drop). So 3.1v roughly.

Am I on track here or way off the mark?


Pauli
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Messages In This Thread
Woodstock power supply - Paul Dale - 01-06-2017 09:23 AM
RE: Woodstock power supply - AndiGer - 01-06-2017, 01:53 PM
RE: Woodstock power supply - PANAMATIK - 01-06-2017, 03:31 PM
RE: Woodstock power supply - hibiki - 01-06-2017, 05:56 PM
RE: Woodstock power supply - Paul Dale - 01-07-2017, 10:00 AM
RE: Woodstock power supply - jebem - 01-07-2017, 05:39 PM
RE: Woodstock power supply - PANAMATIK - 01-07-2017, 10:34 PM
RE: Woodstock power supply - Hans-Peter - 01-07-2017, 11:09 PM
RE: Woodstock power supply - Paul Dale - 01-08-2017, 03:16 AM
RE: Woodstock power supply - Paul Dale - 01-08-2017, 04:51 AM
RE: Woodstock power supply - PANAMATIK - 01-08-2017, 08:45 AM
RE: Woodstock power supply - Paul Dale - 01-08-2017, 09:51 AM
RE: Woodstock power supply - PANAMATIK - 01-08-2017, 12:54 PM
RE: Woodstock power supply - Paul Dale - 01-08-2017, 08:49 PM
RE: Woodstock power supply - Harald - 01-09-2017, 12:24 PM
RE: Woodstock power supply - Paul Dale - 01-10-2017, 02:48 AM
RE: Woodstock power supply - Harald - 01-10-2017, 04:50 PM



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