On Sat, 6 Nov 1999, Robin Watts wrote:

> Urm, there are 2 ICs on my board (+ at least 2 transistory thingies
> big enough to have heatsinks on). I can't seem to match either of the
> sets of hieroglyphics on the ICs to anything in the Maplin catalogue.

It may have been Farnell. My memory is vague, given that it was over a
year ago. Maplin do carry the MOSFET part (IRF840).

> The 2x3 pin one has 4N35 and 710ATK19 on it. The 2x4 pin one has
> ?74D0E6T and UC3842P on it. Does this mean anything to anyone?

Oops, I forgot about the opto-isolator (the 2x3 pin device). That's
unlikely to be at fault. The UC3842P is the switching regulator.

The two 'transistory' like things will be the MOSFET and a rectifier. The
device nearest the 'mains' section is the MOSFET, the device nearest the
5vdc section is the rectifier.

As it happens, I have a spare UC3842AN. The only difference between the
'P' and 'AN' part is the isolation voltage. The 'AN' part is a bit lower,
but still sufficient for the purpose.

Email me your address off-list and I'll post it to you if you're
interested.

Cheers, Steve