hello

[abe]

  I am very interested in this stuff. I,m reading as much about this as I can. I kinda new to this although I have made several cells now started out with wet and now make dry only. This is a fun hobby that has a big payback. My question now is can I make a PMW from a 12 v drill. I took one apart the wires seem small don't know if they can handle the load. Anyone have any thought?
                                                Abe     

[Bob]

Welcome Abe ! glad to have ya aboard !
...
I also have a veriable speed drill that the berrings are Kapoot as well as the armiture in the motor... but looks as if the trigger package is USEABLE for something !
... the problem is the amp handling capability... at the most the drills are 1/3HP
and that would transulate to very low amperage .
However along the same lines there is a DC to DC motor speed controler I believe thats what it is called at harbor Freight tools that is capable of 30 amps if I  remember correctly that may well do the job your after.
 I have hurd tell that Motor speed controlers for things like Router motors and electric drills won't work because they work on AC power not DC...so that would include the electric veriable speed drill goodies !
 I don't know this for a fact so it would be wize to check it out more to be sure, Manta here could probly tell you weather or not they could be used and what amps they would be capable of .
...
Personally I think the best PWM I saw was one that was ran from a simple 555 IC timer that drove a raft of Mossfets and the design would allow you to expand the design to almost any amperage load desired.... I believe I saved the design somewhere on my computer but who knows where it wound up at ! HAHAHAHAH
...
there are Many PWM's on the market some at very reasonable prices , some not most handle 30 amps max... and for serious cell work thats not nearly enough,  a few guys reported that they got 100amp Pulse wave Modulators, but I think most of them made their own....
and sense I can't see fer crud anymore, I am reluctant to try and solder up my own !
so I have had my eyes open for an alternative for a long time and havn't seen any!
....
hopefully the guys here will help steer you in the right direction, if nothing else with where to get a good one for your needs.
...
again, Welcome ... good to have you with us !
Bob..........

[abe]

Bob thank, you for your reply. I'll check with harbor freight and see what they got.
                                                         Abe

[scratch1676]

dont buy a pwm off ebay I have and they wont handle what they say they do.  I bought a 100 amp pwm off ebay and put about 45 amps thru it and it melted the solder off the terminals.  you can look thru the pics on this forum and see what I did if it helps or I have other pics if you need them.

[abe]

scratch I saw your pic very impressive. I like the way you used steel for the outside plates. I tried that but drilling and tapping was to hard. Good Work... Now where did you get your pmw,I'm not sure of buying off the Internet,so many people want to rip you off...