Current Regulator
Current Regulator
(OP)
I am trying to run a custom heater element at its max power capacity 400w. It runs on 110vac. I would like to run it at max power continuously.
What can I purchase or build that will keep the voltage at 110vac but regulate the current such that I am only supplying 400w?
What can I purchase or build that will keep the voltage at 110vac but regulate the current such that I am only supplying 400w?






RE: Current Regulator
Rafiq Bulsara
http://www.srengineersct.com
RE: Current Regulator
Rafiq Bulsara
http://www.srengineersct.com
RE: Current Regulator
Is it that you have a thermostat that switches off now and then and that you want the heater to run continuously, without the off periods?
If that is so, you may need to consider the risk that your heater will self-destruct or set the surroundings on fire.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Current Regulator
Im planning to just use an AC Variable Voltage Output Transformer, and an ammeter to ensure I dont provide more than the rated wattage (400w) other wise the thing sucks up a bunch of power and burns out(experienced that already). hehe.
RE: Current Regulator
RE: Current Regulator
RE: Current Regulator
RE: Current Regulator
RE: Current Regulator
so obviously the feedback is no good other wise it wouldnt have overheated/burnt out. To prevent this from happening i am going to use a volt/percentage controller to regulate the power provided to the element. ill have to do some calibration, but its better than going through elements.
(the thermocouple is not exactly where the hottest part of the element is therefore theres a delay in the controls.)
RE: Current Regulator
There are a few things you didn't tell us up front that may have been important.
Although you may think that it is obvious that the feedback control doesn't work, it may not be so obvious to the rest of us.
Hire someone who is familiar with the equipment to spot the trouble.
Some PTC heaters draw much more than rated current when starting in a cold ambient.
Many heaters are subject to burn out if the physical installation is not done correctly.
Hire an expert.
This may turn out to be an instance when the cost of an expert is less than the eventual cost of damages and repairs.
Bill
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"Why not the best?"
Jimmy Carter
RE: Current Regulator
Resistance, Voltage and current is governed by Ohm's law, you keep two of those three constant, the third will remain constant. I still fail to see what is special about what you are doing. Others have eluded to that too. If you are not using up or removing the 400W heat somewhere, you cannot keep that or any amount of heat source on indefinitely. All you need is a thermostat or equivalent.
Rafiq Bulsara
http://www.srengineersct.com
RE: Current Regulator
I appreciate the advice everyone has given me. Im in a company where engineering expertise & funding is scarce. I wouldnt be in this forum if it werent for this situation.
RE: Current Regulator
RE: Current Regulator
Thermal side:
I need to heat up just the air inside a small vessel up to 900F. The vessel will be pressurized to 350psi. (Flow is optional)
It sounds simple but it has been a challange for me.
My option is to deliver hot air from another source inside the vessel at high pressure low flow.
or
Put an element inside the vessel and heat up the air without radiating excessive heat to the vessel.
RE: Current Regulator
900F is above the capability of most resistance heaters. To supply the thermal losses may take a heater element temperature somewhat in excess of 900F. Have you considered using a mineral insulated resistance heater?
I type slow.. You owe me 12 cents. Grin
Is your vessel good for possibly 1100F with a safety factor?
Bill
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"Why not the best?"
Jimmy Carter