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Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

Hi. I require this diagram but the components cannot be displayed well. I was able to supply the source of the diagram to download in better resolution.

Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

Found the fault, it was a faulty 12v Zener diode that was stopping the MOSFET that switches the 220V power relay from turning on.

This relay gets turned on when the 24V DC that powers the control board is ON.

There are 2 paths the 220V AC can travel, one is through a number of thermistors in series which soft start the 310V DC power supply.

Once the 310VDC is up the 24VDC is also established which then switches the relay and the 220V directly to the 310V DC supply bypassing the thermistors.

If there is any problem with the relay circuit and it does not energise the thermistors will get hot from providing the power to the welder and their resistance increases and the welder powers down. If you just leave it and wait the welder cycles continuously from off to on as the thermistors heat up then cool down.

Attachment 1710525

Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

Originally Posted by Denis G

I've copied a page from this manual....

Thank you.

Yes the VRD is for the mining industry, the original market for this welder. it reduces the voltage to comply with mining regulations. When you are working in the actual earth and wet by water with mineral salts dissolved in it a shock from a welder can lead to a fall or worse.

But the VRD has a switch on the back of the welder which I always leave off, I have checked it in VRD mode and it still powers off but after a much longer period. I am pretty sure from looking at the circuit diagrams that it must be related to the thermistors which take the same time to soft start the welder when it is powered up.

I have worked out the operation from the circuit diagrams and will find the fault when I work on it today.

Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

I've copied a page from this manual:
https://www.manualslib.com/download/...Arcmaster.html

Looks like "VRD" stands for "Voltage Reduction Device" and it will go into sleep mode to save power.

Have you actually tried welding with it? You may be able to keep the power supply running by putting a resistor across the output terminals (between 148 -193 ohms), but I'm not sure what wattage resistor you'll need.Attachment 1710393

(Edit: You probably don't need to keep the power supply going all the time. It seems that it should wake up when it senses that it needs to by itself.)

Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

Oh yeah maybe someone could help me out on the original fault. It switches off after about 30 seconds but everything is normal. All voltages check OK. No warning LEDS, all voltages just drop as the main caps discharge. The power OK LED dims until it is dead. Switch off and wait a few minutes and switch back on and it powers back up again....rinse and repeat.

Re: Thermadyne D.C Inverter 160 circuit diagram or any other info

Well here's for the next person that searches on a Thermadyne D.C Inverter 160.

A search on the term "ARC 160" returns the best info on this model.


Attachment 1710387

Thermadyne D.C Inverter 160 circuit diagram or any other info

Has anyone got a circuit diagram for a Thermadyne D.C Inverter 160 see attached pics?

I have seen identical welders under other names.

It switches on with green power LED on and no red lights. Then switches off after 30 seconds and then needs to be left for main caps to discharge, then if powered back on it works before switching off again after 30 seconds.

I was planning to use it for a 3D welding printer I am hacking together.

I need to use an Arduino to hack into the current control circuit so I can use the Arduino to alter the current.

I also have some monster IGBTs that I plan to use to pulse the DC output.

I will have to draw-up a circuit diagram and research the individual components but I am sure this is a Chinese made mass produced under several brand names welder that someone already has a circuit diagram for.

Any help with info or a circuit diagram would be much appreciated.