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eloid
07-19-2009, 06:33 PM
need a simple but effective controller for my hotwire
looking for plans and info for diy unit
need a current /tempture controller
please post info pic etc

CJL5585
07-20-2009, 02:27 AM
See Attached .jpg

eloid
07-26-2009, 10:09 AM
See Attached .jpg

can you explain how the triac works, not sure if it will modulate the temp
or regulate it?... i think it may be like a light dimmer idea, with no feedback
to regulate the temp is just a simple current limiting circuit... looking for a pwm or modulating circuit to cool the wire when light cuts are made
and when temp is dropping increase current automaticly...

CJL5585
07-27-2009, 09:34 PM
can you explain how the triac works, not sure if it will modulate the temp
or regulate it?... i think it may be like a light dimmer idea, with no feedback
to regulate the temp is just a simple current limiting circuit... looking for a pwm or modulating circuit to cool the wire when light cuts are made
and when temp is dropping increase current automaticly...

What if the temperature was controlled by modulating the positive portion of the secondary transformer AC voltage 60 times per second?

Well, that is the way it works. The variable potentiometer setting (which is controlled by the operator, and who determines the cutting wire temp) completes the circuit.

The pot setting and cap create a variable charge time which determines how long the triac conducts current during the positive portion of the AC sine wave. During the negative portion of the AC sine wave, the triac is switched off. Since the sine wave is a 60 hertz signal, the control voltage, and also the current to the cutting wire is turned on and off 60 times per second. Changing the pot setting will increase or decrease the amount of time the triac conducts, thus increasing or decreasing the temp.

If you are looking for a temperature controlled, closed loop controller, then it would probably be best to purchase one. This circuit could probably be modified to use a thermistor for temperature control, but would require some additional design.

CJL5585
07-27-2009, 09:47 PM
https://www.abbeon.com/store/item.cfm?code=1950

These units are represenative of the circuit I submitted to you. They DO NOT have internal temperature control, but cost hundreds of dollars.

eloid
07-28-2009, 09:03 PM
https://www.abbeon.com/store/item.cfm?code=1950

These units are represenative of the circuit I submitted to you. They DO NOT have internal temperature control, but cost hundreds of dollars.

I have been looking for pwm module, that whould allow the user set the desired current, and freq as needed. As the out of the pwm would sence the current, it would change the frequence and duty cycle thus changing and maintaining the current output as load and cut is occuring. the duty cyle would be auto adjusting for the desired current / temperture.

CJL5585
07-28-2009, 09:16 PM
I do not have any knowledge of any manufacturer who makes such a unit.