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It's a 9.6V drill (bought in the UK - KC9682C, type 2). Pulled the drill apart and the separate MOSFET (I assume!?) in this is blown - sortov obvious as it has a big chunk missing! Then pulled the controller apart (this reads, if I
remember, 9.6V, 20A) - one of those things that spits their contents at you when you disassemble them!! Was gobsmacked that this has a tiny surface mounted insertable white (ceramic?) PCB with ONLY the following: 8 pin IC, surface
bonded pot plus an R each side, one other R, 2 unidentified SMCs (one is a diode I believe). And that's it!!
OK - so what are the goodies?
The 8pin SMC is marked 'CPX94' then separate line '0605' - what IS this??? Can't find it in any of the chip directories.
The separate T220 is a MOSFET because, well, what else would it be (maybe an IGT?). The terminals were all nicely G|D|S as well. And a T220 is NOT something I expect to see a 20A transistor in!
So, replaced the fractured T220 with a grunty MOSFET - and guess what??? It now cycles between off and full with about a 10sec period (my memory?) regardless of trigger position (except that 'full' is really full and 'off' is really off, plus shorts the motor - thanks to a set of mechanical switches).
I'm confused and amazed - can anyone *please* elicidate? Especially - I want to know what IC can do this (it's not a 555 I am sure!??).
Regards, [email protected]
remember, 9.6V, 20A) - one of those things that spits their contents at you when you disassemble them!! Was gobsmacked that this has a tiny surface mounted insertable white (ceramic?) PCB with ONLY the following: 8 pin IC, surface
bonded pot plus an R each side, one other R, 2 unidentified SMCs (one is a diode I believe). And that's it!!
OK - so what are the goodies?
The 8pin SMC is marked 'CPX94' then separate line '0605' - what IS this??? Can't find it in any of the chip directories.
The separate T220 is a MOSFET because, well, what else would it be (maybe an IGT?). The terminals were all nicely G|D|S as well. And a T220 is NOT something I expect to see a 20A transistor in!
So, replaced the fractured T220 with a grunty MOSFET - and guess what??? It now cycles between off and full with about a 10sec period (my memory?) regardless of trigger position (except that 'full' is really full and 'off' is really off, plus shorts the motor - thanks to a set of mechanical switches).
I'm confused and amazed - can anyone *please* elicidate? Especially - I want to know what IC can do this (it's not a 555 I am sure!??).
Regards, [email protected]