Model Forum / General / Models / July 2008

Before proceeding, please be sure you will is up to date and your
significant other(s) know where you have hidden your important papers.

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.

                                                                           
                           Val Kraut

    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. :-)

                            Bruce

I do not recommend this.  Your intentions are good but you're a bit
misguided.

Here is what I know  about electric blankers (form my own
observations):

*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.

Peteski

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
of it.

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,
too.

2 D cell batteries power the foam cutter I have...........Hobby Lobby $4.00
on sale!