# 3 mosfets in parallel on Induction heater.

#### JonSea

##### Well-Known Member
Better, go to Arrow.com and search on the part number to select the package you want. The link I posted above goes to the SOIC package e en though I was looking at the DIP.

#### gary350

##### Well-Known Member
Looks like the IRS2453 circuit above does not operate at resonance frequency, it operates at a preset frequency but no information what KHz that is or how to set it?

Circuit above shows no RC circuit, no capacitors in parallel with the load coil. Everything I read says the capacitors are important it gives the work coil power to do its job. I was reading where someone built this circuit it says to add capacitors or circuit does not work.

These circuits are frustrating. I don't like building circuits that don't work. If I build this with parts laying all over the work bench its not hard to make changes, but if I build a nice circuit it is not easy to make changes.

#### shortbus=

##### Well-Known Member
These circuits are frustrating. I don't like building circuits that don't work. If I build this with parts laying all over the work bench its not hard to make changes, but if I build a nice circuit it is not easy to make changes.
But yet you continue to resist doing what people tell you. Maxheadroom has given you many, many times a link to a induction circuit that does work and you have never even tried to make it.

#### gary350

##### Well-Known Member
But yet you continue to resist doing what people tell you. Maxheadroom has given you many, many times a link to a induction circuit that does work and you have never even tried to make it.
I can not build it if I don't have all the parts. At the moment water cooled heat sinks are the biggest problem. Know knowing how many BTUs of heat is needed how much cooling will it need. I am looking at cooling radiators 2" thick, 6" wide, 8" long, 3/8" copper tubing. I need a closed circuit water pump, Little Giant pumps are small but not small enough for this the pump needs 3/8" tubing fittings. I don't have, pump, radiator, heat sinks yet. I'm not finding any water cooled heat sinks for FOUR 1GBTs. This will all need to be built into a case with the power supply. It seems stupid to build this to run on anything less that 240vac from a workshop welding plug for 60 amps.

#### ChrisP58

##### Well-Known Member
Looks like the IRS2453 circuit above does not operate at resonance frequency, it operates at a preset frequency but no information what KHz that is or how to set it?

Circuit above shows no RC circuit, no capacitors in parallel with the load coil. Everything I read says the capacitors are important it gives the work coil power to do its job. I was reading where someone built this circuit it says to add capacitors or circuit does not work.

These circuits are frustrating. I don't like building circuits that don't work. If I build this with parts laying all over the work bench its not hard to make changes, but if I build a nice circuit it is not easy to make changes.
The datasheet for the IRS2453 shows it as a self oscillating driver. There is a graph giving the fixed frequency based on the chosen Rt and Ct .

#### gary350

##### Well-Known Member
The datasheet for the IRS2453 shows it as a self oscillating driver. There is a graph giving the fixed frequency based on the chosen Rt and Ct .
OK I see that now. Rt = 1K and Ct = 470pf = about 70KHz Online industrial heat treating information says, 65KHz is very good for deep heating, 200KHz is better for skin effect heating. I ordered two IRS2453 today. Now I need 14 pin sockets if I smoke 1 it will be easy to replace.

What is good way to keep RF out of DC power supply?

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#### fukitol

they always charge ($20.00 +1 left ball) for each damn item! they're killin me on that shippin! JFS #### gary350 ##### Well-Known Member they always charge ($20.00 +1 left ball) for each damn item! they're killin me on that shippin! JFS
Buy on Ebay find a seller in the USA that has reasonable prices you receive the parts is 3 days. I order from Colorado & Texas seller.

If you can wait 2 to 3 weeks order from China , Hong Kong. etc. The parts that come from China are made for American companies they are good parts often 10 to 40 parts for $1 or$2 free postage.