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Full Version: Corvus 500 calculator - can it operate on genuine power adaptor with no batteries?
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(09-26-2016 06:13 PM)emersone12 Wrote: [ -> ]Can the Corvus 500 scientific calculator run off the genuine AC power supply adaptor pack only, without batteries present in the battery compartment, just like the HP-45, without frying the internals like the HP-25 ? (ie does the Corvus 500 need batteries present in the battery compartment at all times as an integral part of the circuit when operated using the original genuine Corvus supplied AC power supply adaptor pack?)

I remember reading that you can, but why take a chance? They aren't making any more of those.
In case you haven't seen this
(10-15-2016 01:47 AM)emersone12 Wrote: [ -> ]How to add photos to posts?

When you're editing your post (new or old), click on the Inset Image toolbar icon.
(11-30-2016 01:00 PM)emersone12 Wrote: [ -> ]Very rare alternative version? For the asking price it presumably must be more rare than the HP-70......... http://www.ebay.com/itm/Calculator-Dumon...SwiONYOxoo

If you judge rarity on the asking price... ;)
(11-30-2016 02:39 PM)emersone12 Wrote: [ -> ]A search for any Dumont branded calculator produces zero results, Emerson did the E12...

Not true, here you can find a DuMont Corvus Model 615 (and a 500, maybe the one for sale)...

How's that they are all located here in Italy?!?
Very odd; they used the logo of the old Dumont Laboratories company, one of the pioneers in the early days of electronic television. Some more info about the company can be found here.
-Adam
Do not apply the original wall wart voltage to calculator without rechargeable batteries in place. Test the wall wart and you will see 9volts at the plug end. This is fed into the nicads and exits the nicads at 3.6 volts.

With the wall wart used and soldered direct to the board you will be placing a 9volt charge to the PCA. you may get away with it!

If you remove the batteries use a wall wart with a voltage around 4-5 volts.
Do not apply the original wall wart voltage to calculator without rechargeable batteries in place. Test the wall wart and you will see 9volts at the plug end. This is fed into the nicads and exits the nicads at 3.6 volts.

With the wall wart used and soldered direct to the board you will be placing a 9volt charge to the PCA. you may get away with it!

If you remove the batteries use a wall wart with a voltage around 4-5 volts.
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