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Woodstock Battery Contacts
06-27-2020, 11:49 AM
Post: #1
Woodstock Battery Contacts
I want to share an approach for renewing the battery contacs of Woodstock calculators like HP-25, HP-29C.

Often they are in very bad corroded condition. Therefore I tried to replace them. The old contacts must be removed by drilling with a 2.5 mm drill. They are made of nickel plated solid brass.

[Image: uc?export=view&id=1K9HkGW5JMP75ojbU2lLpm0DZTOlTF0sQ][Image: uc?export=view&id=1aDxNxGVecduLSXuz60wpxkoJ6niLVoLt]

I inserted two 2.5x6 mm "round head rivets" with 2.7x6 mm brass washers. After removing some solder resists from the board I could solder the washers to the copper traces leading to the battery.

[Image: uc?export=view&id=1_FKTi_drcrTmaHJgd71HffR_nbgMlH6m]

The final prototype

[Image: uc?export=view&id=1pPGNehEk-kvvqR3cr3Gi3R45o5zuKV43]

I made the washers a little bit smaller with a Dremel tool, you need to use AA flat top batteries. Ideally would have been 2.7x5mm washers, but I didn't find them. Even better if they would be gold plated. I bought some gold electrolyte and perhaps will make a try.

Bernhard

That's one small step for a man - one giant leap for mankind.
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06-27-2020, 10:41 PM
Post: #2
RE: Woodstock Battery Contacts
Thank you!
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