On Tue, 19 Sep 2017 20:40:33 +0100, Geo
wrote:

On Mon, 18 Sep 2017 23:47:47 +0100, T i m wrote:


Just for you Chris, I took the bottom off my PU-1D and took a couple
of pictures of what I found inside. ;-)

https://www.dropbox.com/s/x4g0txwl81...d%201.jpg?dl=0
https://www.dropbox.com/s/x8lvblyq4q...d%202.jpg?dl=0

I think (because it's wrapped up in tape) there is a big electrolytic
cap in there as well.

Can't see all the components, or be sure of the colours on those brown
bodied resistors but my reverse eng sketch is he-
http://tinypic.com/r/24v3zm0/9

Woah, that's amazing Geo, just from those two pictures. ;-)

Would you like me to confirm what the missing values are (the vertical
component and the cap)?

Looks like a similar version to :-
http://spritesmods.com/?art=wtcpled&page=2
detecting the transformer volts drop when the switch closes.


Yeah, I think I remember that being the only way we worked out we
could do it back then (well, not without a current shunt of some sort
etc).

It's funny, after making and fitting it I'd sorta forgotten I had ...
because it was out of sight and 'just worked'. ;-)

The PCB was just stuffed into a little zip top component bag and it
all bundled in there and the base put back on. I probably intended
doing it properly sometime but ... ;-)

Cheers, T i m