"Gareth Magennis" wrote in message
...
"lardconcepts" wrote in message
...
On 18 May, 21:28, Franc Zabkar wrote:
On Mon, 18 May 2009 13:01:26 -0700 (PDT), lardconcepts
put finger to keyboard and composed:
Spear and Jackson Cordless Drill model SJ-CD18KUK
Worked fine for years, mechanically sound. Now after a short time of
use, there's a puff of smoke and it slows right down. Upon opening up,
I see this smoke is pouring from the centre of a 3-legged regulator
device on a heatsink.
I have looked herehttp://www.maplin.co.uk/Search.aspx?menuno=12489
but can't find anything with similar numbers. The markings are
NEC
K2 ??4
82M
The ?? are two numbers I can't see, as that's where the burnt hole is!
I suspect it is a 2SK2??4 MOSFET which is being switched in PWM mode
to control the speed of the motor.
One possible suspect is a 2SK2984 20A 30V "SWITCHING N-CHANNEL POWER
MOS FET INDUSTRIAL USE ... designed for high current switching
application":http://www.datasheetarchive.com/pdf-...ts-22/DSA-4325...
For other possibilities, check page 301 and onwards of this NEC
selection
guide:http://www.datasheetarchive.com/pdf-...ts-16/DSA-3172...
Wow, Franc, I am very impressed! OK, sadly it seems that I might have
my work cut out finding this chip. Certainly not Maplin that sells it,
or in fact any of those chips.
But you have given me a very good start. I wish I knew as much about
electronics.
If you want to learn about electronics, don't ever go to Maplin. You will
be told and sold a load of rubbish.
Here's somewhere else you can try if Farnell, RS, CPC etc are tricky with
one off small quantities:
http://www.cricklewoodelectronics.co...ewood/home.php
Gareth.
How do you get on with Cricklewood these days, Gareth ? I used to use them a
lot, but since they became part of that bigger group, I seem to have had
endless problems with items not being in stock - although you don't get to
know it until the delivery is missing that item - and then having to wait
sometimes a couple of weeks or more, until they can get it. A couple of
times, that caused me embarrassment with a customer, when I had told them
when their repair would be ready, based on having ordered a part from them,
only for it not to turn up, so recently, I have stopped ordering from them.
Arfa