BY AL JASZEK
Into A Darkroom
What can you do with a dead
microwave oven, a surplus wooden
box, a power cord, and a socket?
My son is an avid amateur photographer. He had
even started developing black and white negatives
at home. You say, why bother with that? Well, he has
a number of antique cameras, one of which is a 1917
Vest Pocket Kodak which I gave him. He even made his
own roll of film for that camera. (If you want details, go
to his web site, squirrelsgolikethis.com). So, what does
this have to do with electronics? People who do their
own developing need darkroom timers. So, he asked
me to design and build one for him. I could have gone
out and bought one, but there is satisfaction in doing
something for yourself.
A few years ago, our Litton microwave oven died.
One of the door interlocks had failed and it would have
cost too much to replace. So, I took the unit apart and
saved the magnetron, the timer assembly, and the
power transformer. As you might have guessed by now,
I have a timer assembly that I can use for this project.
I was fortunate in that the schematic of the entire
unit had been pasted into the control section of the
microwave. The timer assembly was also easily removed
as a unit. So, what else did I need?
The entire Parts List for this project included:
1. Timer assembly
2. Power cord
The wooden case I used was purchased for
about $2 many years ago from a surplus store. It
housed a medical device which enabled the user to
transmit heart monitor information to his doctor. As
pure chance would have it, it was just large enough
to hold the entire timer assembly. Before I made
any modifications to the case, I made sure that I
would have sufficient clearance within it for all of
the components. I then placed the timer assembly
on the case top and traced the outline before
cutting the lid to accept the timer module.
Ihave quite an extensive junk box. I save bits and pieces
from expired appliances and electronic gadgets. I also
have a great source of electronics from our town's
recycling center. The electronics, the tires, the metal
bits, the wood, the paper, the garbage are all collected in
separate clean areas. Since our New England town does
not have garbage pickup, most residents take their
disposables to the town's recycling facility. People are
welcome to salvage what they can.