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It's alive, the franken41
03-20-2016, 09:36 PM
Post: #3
RE: It's alive, the franken41
The HP-41CV is still alive and well, passing all diagnostic tests. I will try to upload some pics soon.

My real hope was for the power pack. a LiPo battery using a charge/boost adapter (SparkFun Power Cell, PRT-11231) that fit well within a 3D printed housing. The power supply works well for 3-4 days with a 400mAh-500mAh battery but the no-load current on the boost circuit is just too high and quickly depletes the battery to the low voltage protection point. I have been comparing load with larger LiPO batteries, NiMH, and NiCad batteries and it is the boost circuit that is depleting too quickly.

Maybe I can use a solar cell mounted on the battery housing, I can then just flip over the calculator when not in use to keep the batteries charged.

So far the best power solutions I am finding for the 41C's are using the standard battery housing (OEM or 3D printed) with either NiNM N-cells (with a 3D printed AA:N adapter for recharging the cells) or standard N-cell alkali batteries, and rebuilt NiCad pack using 1/3AAA cells.
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Messages In This Thread
It's alive, the franken41 - Nate Martin - 03-05-2016, 02:05 AM
RE: It's alive, the franken41 - Jlouis - 03-05-2016, 11:27 AM
RE: It's alive, the franken41 - Nate Martin - 03-20-2016 09:36 PM
RE: It's alive, the franken41 - Hans-Peter - 03-21-2016, 11:33 PM

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