[TriEmbed] Coffee roaster sanity check

[Brian]

Hi Craig,

I'll give your schematic another go-over after a sleep cycle (I'd be 
fast asleep now but one of my Christmas presents was the 2017 Twin Peaks 
miniseries on Blu-ray, so here it is 1:30 AM...)

For now, something you said caught my eye:
>> Did you ever (very carefully) measure the voltage across the motor while the popper was powered?
> 
> Yes. 0.134 Amp AC
> Hmm... as I type that, it seems it should be a DC reading...

That sounds like a current reading (Amp), not a voltage reading.  So, a 
few things:

a.  If you can connect your meter on the DC side of the popper's bridge 
rectifier (directly to the motor's terminals), connect it there and set 
it to DC Volts for the reading.

b.  If you can only connect it on the AC side of the rectifier, set it 
to AC Volts.

c.  Either one of these measurements should be made in parallel to the 
motor (as compared to in series for a current measurement).

d. A reading of current in the motor would definitely have a 
(misleading) AC component due to the ripple caused by the rectifier.

e. Give the popper a few seconds to heat up before you record your 
measurement; the resistance of the heating element will change as it 
heats up, changing the voltage seen by the motor.

f. Be careful!  Neither burns nor shocks are any fun.

Til later,
-Brian