J
John Gilmer
I had a old microwave over which I picked up at Monkey Wards (now out of
business) back in 1977/78. It just kept on running and running and
running. The "touch" keypad was difficult to operate and it was clear that
it wasn't quite as powerful as it was but it was there.
Last week, it stopped. We had already planned on replacing it with an over
the over model (more about that in another post) so I wasn't upset.
I decided to take it apart "just to see."
Some comments on what I found:
1) That thing was SOLID! It was really, really well put together.
2) It had two (2), two pole (plus pilot) contactors. One was for the
"browning" element. The other was for fail safe purposes. The final
switching to the transformer was by some kind of triac (there was a diagram
showing all the power and contactor wiring -- the "logic" just showed the
120 volt and "safety" and sensor interfaces).
3) When I had opened things up, I almost wished I had been a little more
careful (because of dirt, I ended up bending the outer sheet metal to get it
off). Turns out the Triac (or whatever) had broken off from it's heat
sink. Without the heatsink, it failed (the proof was that the wiring to
the triac showed some heat damage to the insulation. I was almost tempted
to get another triac and put the thing back together.
I "salvaged" a bunch of stuff like:
1) The control panel -- it's powered from 120 volts. I might be able to
find some use for it. My older girl said she might enjoy having it so I
might find some way of getting it powered and not be a shock hazard to her.
2) The contactors (both nameplated for 15 amps.
3) The MAIN transformer, high voltage diode, and voltage doubling
capacitor.
4) The magnitron tube (still has the heat sink but I want to see
how they focused the magnetic.
5) The permanent magnets (two flat "donuts". The magnetic
circuit was completed by some heavy gauge sheet steel. I might keep them
and play with the effects on conductors dropped between the poles.
6) Some power hardware including a combo fuse block and male "slip on"
terminal block.
7) The MANY microswitches (safety, door switch, temperature probe
sensor)
8) The overheat sensor on the microwave cooling fins (NC).
9) The thermal fuse that detected whether the contents of the over
were on fire!
10) The 50 rpm "stirrer motor"
11) The cooling fan.
For now, I will just move the stuff to a "junk box."
If anyone has any projects to suggest, let me know.
Anyway, I figured some of your would be amused by the whole thing.
business) back in 1977/78. It just kept on running and running and
running. The "touch" keypad was difficult to operate and it was clear that
it wasn't quite as powerful as it was but it was there.
Last week, it stopped. We had already planned on replacing it with an over
the over model (more about that in another post) so I wasn't upset.
I decided to take it apart "just to see."
Some comments on what I found:
1) That thing was SOLID! It was really, really well put together.
2) It had two (2), two pole (plus pilot) contactors. One was for the
"browning" element. The other was for fail safe purposes. The final
switching to the transformer was by some kind of triac (there was a diagram
showing all the power and contactor wiring -- the "logic" just showed the
120 volt and "safety" and sensor interfaces).
3) When I had opened things up, I almost wished I had been a little more
careful (because of dirt, I ended up bending the outer sheet metal to get it
off). Turns out the Triac (or whatever) had broken off from it's heat
sink. Without the heatsink, it failed (the proof was that the wiring to
the triac showed some heat damage to the insulation. I was almost tempted
to get another triac and put the thing back together.
I "salvaged" a bunch of stuff like:
1) The control panel -- it's powered from 120 volts. I might be able to
find some use for it. My older girl said she might enjoy having it so I
might find some way of getting it powered and not be a shock hazard to her.
2) The contactors (both nameplated for 15 amps.
3) The MAIN transformer, high voltage diode, and voltage doubling
capacitor.
4) The magnitron tube (still has the heat sink but I want to see
how they focused the magnetic.
5) The permanent magnets (two flat "donuts". The magnetic
circuit was completed by some heavy gauge sheet steel. I might keep them
and play with the effects on conductors dropped between the poles.
6) Some power hardware including a combo fuse block and male "slip on"
terminal block.
7) The MANY microswitches (safety, door switch, temperature probe
sensor)
8) The overheat sensor on the microwave cooling fins (NC).
9) The thermal fuse that detected whether the contents of the over
were on fire!
10) The 50 rpm "stirrer motor"
11) The cooling fan.
For now, I will just move the stuff to a "junk box."
If anyone has any projects to suggest, let me know.
Anyway, I figured some of your would be amused by the whole thing.
