There was as ad on TV tonight for a service that allowed you to create a
will for $63 - perfectly legal. If buying a real controller is less than
this - buy one, if its more, make a will, then modify your blanket control
but please let your wife know how to list things on ebay.
: There are two controllers. The controller I where I snipped off the
: insulated power wires has a regular two prong plug (2 wires) for the
: wall 115 Vac outlet. Inside the controller is a heating "zig zag" wire
: assembly next to a 3/4 turn moveable knob contact for adjusting the
: blanket's set temperature. I would believe the "zig zag" wire heats
: up to cut off the power supply at set point.
What you are describing sounds more like a rheostat than a
temperature control. If you have a multimeter, it should be
easy enough to set it to the voltage sacle and measure the out
put from the controller.
There are several articles describing how to build one of
these things on the net. googleing "nichrome cutter" led to
more articles than I care to count. :-)
"I like bad!" Bruce Burden Austin, TX.
Having seen the results (*) from a broken electric blanket, I'd still
have to say be very careful, and I really do hope it works out for
* - A destroyed bedroom - $5,000.00
- Clean up and airing out the rest of the house - $1,000
- Having at least one wag claim thet someone forgot to put out the
I do not recommend this. Your intentions are good but you're a bit
Here is what I know about electric blankers (form my own
*YES*, there is 120V AC going applied to the heating coils of the
electric blanket. It does not use any type of a voltage step-down
device. The heating element is well insulated. I gather that
manufacturers think that it is safe for use.
Some newer blankets have a sensing circuit in the controller which
cuts power to the heater the instance there is a break in the
circuit. They also use a polarized plug so that the heating coil will
not be on the live side of the circuit once the safety cutoff
occurs. Older blankets did not have this feature.
The "controller" that you've mentioned is nothing more that a simple
thermostat circuit. It is actually more like a cycling timer and
thermostat Very simple design using an adjustable bi-metal switch.
All ti does is to cycle the full power off and on to the blanket. The
cycle time is controlled by the value dialed on the knob and also
affected by the ambient temperature.
The on/off ratio is the lowest at the lower settings and fully "on" at
the highest setting. The ambient temperature offsets this a bit (the
colder it is the more "on" time you get).
I do not see how that could be useful for hot wire cuttter. Best way
to control hot wire cutter would probably be a low voltage variable
transformer. Or some sort of Triac controlled circuit (similar to
standard dimmer switches). The "dimming " circuit could either be
used on the high or low voltage side of the transformer.
I thought that I explained it well enough but I guess not. Electric
blaket's controller is purely either fully on or off. The overall
blanket's temperature is the product of the average of the "off" and
"on" time of the controller. But the cycle time is relatively long
(off for about a minute and on for 10 seconds or so in the low
settings). Noting that can be used to control a hot wire cutter. Hot
wire has a very low mass and even if you wanted to control its
temperature by controling the duty cycle of the voltage, the cycle
would have to be much faster (few times a second). The electric
blanket controller is just not a proper device for this application.
A triac-based dimmer would be perfect for this application. Just note
how well it can control the brightness of a light bulb. A hot wire
cutter's thermal inertia is more like a light bulb than an electric
I normally build aircraft in 1/48 and 32nd scale. But every now and then
I'll build a piece of German or Soviet WWII armor in 1/35 scale. I'm also a
sucker for the realism for the Friulmodel metal tracks. Long evenings were
spent assembling these links one by one, I knew there had to be a better
way. Well there is: I found the Trakmaster 01 track linking tool on the
Mission Model website, I purchased one and finally got around to trying it
out on the tracks of a PZ IV last night.
The reason for this email is to announce to all you armor fans that
Trakmaster is a positive joy to work with and is everything Mission Models
declared it to be. All of a sudden the stack of unbuilt Panzers is looking
good. (Incidentally, instructions state that Sherman tracks can not
assembled using the Trakmaster). I even leave the assembled tracks in the
jig after inserting the wire in order to apply super glue.
I rarely praise a product and I've never praised a product on email before,
but the Trakmaster's ease of use really grabbed my attention.
I suspect electric blanket elements are high impedence low current,
high voltage devices.
Foam cutters are very low impedence, hence use high current, low
voltage. Most of the cutters I have seen use six volts or lower. On
mine I used an adjustable battery charger/eliminator, and it worked
fine, but it was a fifteen amp device and I was using about ten amps
I think you would be much better off using a low voltage device, and
you can easily use manual control rather than automatic. Much safer,
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