Adding a cord to a cordless Dremel

[limpport]

So I have a cordless dremel. I don't mind, but the fact that I don't have an extra battery (yet) is frustrating when I run out of juice. So I was thinking about making an corded attachment that would plug into the battery slot.

The pack contains 2 sets of 3 NiCD cells (six total). The output of each set is 3.6v at 700mAh. So I think this will work:

Dremel wall power hookup.jpg (38.57 KiB) Viewed 3235 times

In parallel, voltage does not divide, but current does. That should work, right?

[hailrazer]

Why don't you just find a 3.7v 1.4A wall adapter and hook it to the positive and negative spots on the Dremel. Then it is wall powered ?

And if that is what you are trying to do , then yes that will work. Parallel batteries current adds. Series batteries voltage adds.

[limpport]

That's what I meant. But I want it to plug into the dremel the way the battery does (hence the weird picture, I'll get a photo up tomorrow so you can see what I mean). The dremel is a 2 speed. The 1st speed runs the battery "packs" in parallel (3.6v@1400mAh), and the second speed runs the "packs" in series (7.2v @ 700mAh).

[timmeh87]

mAh isnt mA so the above discussion is terribly confusing.

Have you actually measured the current at 3.6v or 7.2v? Or are you just quoting the battery capacity which does not equal the instantaneous current...?

You would need two voltage sources, one at 3.6 and one at 7.2 to simulate the battery pack if it is switched as you say. Or else pick your favorite speed and go with that voltage.

[OMGpedobear]

a 8.5 V 5 amp ps2 power supply could do nicely with a 1.5 amp 3.3 amp regualtor for the low speed

[timmeh87]

You definitely wouldn't need to go and order a DC-DC converter though

LM317!