[tech] Coke machine lights, empty detection, fans

[Nick Bannon]

On Sun, Feb 03, 2008 at 12:01:21AM +0900, Nick Bannon wrote:
[...]
> The resistors get _hot_. The 4N38A opto on slot 0 is burnt out and gets
> warm. Slot 6 empty detection sometimes works, possibly a dry joint.

I've replaced the opto.

A possible cause of slot 0 burning out could be that the voltage
dropping capacitor on that line has failed short circuit... I don't have
a replacement to hand, but a temporary (?) fix is that I've added a ~27K
resistor to the opto LED input. The opto LEDs only need 2-4mA to light up,
so dropping the 100V input voltage with resistors is not tooooo wasteful.
We'll see if it lasts.

Slot 6's still seems good after its resoldering, so all the empty
detection lines are currently working!

TODO:
> [MTL] and I inspected the fans recently - there were originally two
> mains ones; and one broke. The 12V replacement works fine, so we should
> probably go 12V-only and clean up some unnecessary mains wire.

Nick.

-- 
   Nick Bannon   | "I made this letter longer than usual because
nick-sig at rcpt.to | I lack the time to make it shorter." - Pascal