Hi folks,
I'm a noob when it comes to electronics but am trying to learn.
A while back I bought a cheap battery powered rotary tool / large engraver. It didn't run long on a chanrge and didn't have much power so I opened it up. It had three NiCad cells end-to-end as it's energy store, a simple switch and charged through a jack to which you'd connect the 5v DC power supply.
I decided to replace the NiCads with an 18650 Li-Ion cell and use the following module to charge the cell and prevent discharging;
I've used those modules before with cells taken from old laptop battery packs and LEDs and they work well. However after I modded the case, soldered everything together and tried it (yeah I should have tested it outside the case...) I found it wouldn't switch on. :( However if I momentarilly shorted the DC out to the battery connection the motor would run just fine except if put under very heavy loads, in which case it'd stop. (I killed a couple of the modules messing around trying to fit a momentary contact switch to short across to start the motor.)
Some guy in a forum on that site suggested it was because of the high current draw on start-up of the motor and that I put a capacitor in parallel (?) with the motor it might fix it. However I was unable to engage him any further to get him to tell me more, what size and type of cap etc.
I'm not rich and don't have the funds to buy electronic components and try whenever possible to use salvaged parts. I keep old PCBs and tend to use them as my supply of parts whenever possible...
Can anyone tell me if doing this is likely to work and if so what type and value of capacitor to use please? I seem to recall seeing something similar somewhere, what appeared to be a tantalum capacitor wired across a DC motor. I can see quite a few of those on the various PCBs that I have. If someone can confirm that it might work them I'll get to unsoldering and try to work out what values the caps are that I can find.
Cheers, and TIA.