Hobart Nifty 206

[simon718]

the one that was fitted was N/O, but as the connections to it were crossed who knows whats went on! thinking about it now, there was thermal paste between the thermostat and the plate its attached to, and the bolts didnt look like they'd been touched

 

[simon718]

have tested the switch, seems to work

 

[madkayaker]

time to get it working then

 

[simon718]

jake ss reckons it may need a dedicated power source, and is dc only input. he's never seen one before, im amazed nobody has, what have i bought

 

[madkayaker]

a yellow box might be time to part with the £15 for the manual

 

[R Kraft]

It looks like a large version of a capacitive discharge ignition system.
It looks like it could run off of the welding current.
The welder output voltage would be regulated by a large zener diode,chopped and stepped up by the transistors driving the pot transformer to charge a capacitor.
When the capacitor has charged to a certain level, a thyristor would fire the higher voltage through a HV coil.
Usually it then goes through a spark gap, which changes it to HF HV.
The HV pulse would be superimposed on the welders output voltage,by some loose coupled wires or loops of wire.
Just general theorizing.
Robert

 

[Jake SS]

Most HF boxes will have provision for AC and or DC inputs, they are usually connected to a power source that has a seperate ac supply for the auxillary circuits/ control circuits. Mostly 115v ac. They are attached by the remote socket on the power source for the supply, but apparently this one does not have this facility.

It is strange that it has + and - symbols on the output, as if it is a HF box you would want AC output to run TIG with constant HF for ally !

The power cables appear to run straight through, with one to an inductor/ reactor, which if thats the case the output would be live all the time, unless it has a contactor that I cant see.

If it is DC only what would be the point of having an elaborate box for HF start only.

Also with no auxillary input for control circuits it would have to work off the actual weld voltage for supply.

The pcb with the 3055 transistors looks like a driver board.

HMMMMMMMMMM......???????
Very interested to find out about this box

Cheers
Jake

 

[R Kraft]

The hf is used to maintain the arc channel at low voltages (below 15v or so) even with argon shield gas the arc will sometimes die.
It also allows the arc to start through paint and rust and to start without actual contact, between the work and electrode,

The output AC is low current and rides on the welder output voltage.
When the arc channel is large and well established the HF/AC component of the voltage drops to near zero.

If Simon718 wants, I could sketch a CD inverter schematic from memory.
It wouldn't be a perfect match for his, but might help him trouble shoot.
The thing might even run off of a 12v battery charger, enough to test.
Robert

 

[Omniata]

If it is DC only what would be the point of having an elaborate box for HF start only.

Also with no auxillary input for control circuits it would have to work off the actual weld voltage for supply.

The pcb with the 3055 transistors looks like a driver board.

HMMMMMMMMMM......???????
Very interested to find out about this box

Cheers
Jake

I think the orginal idea for these was a way of doing TIG with HF on industrial sites where Arc welders were present but TIG was only used from time to time.
They just wanted to be able to do it as and when by grabbing a bottle of Ar and an HF addon.....
Or to save on spending a load on a dedicated TIG set when it wasn't being used all the time...

Just my two penneth worth...

 

[simon718]

It is strange that it has + and - symbols on the output, as if it is a HF box you would want AC output to run TIG with constant HF for ally !

The power cables appear to run straight through, with one to an inductor/ reactor, which if thats the case the output would be live all the time, unless it has a contactor that I cant see.

the inputs on the back are polarity dependant also

there is a contacter hidden at the back, which switches the output to the tig side on/off

the large yellow cables you see, run straight from the input to the +/- for the stick side. its quite confusing me also jake

The hf is used to maintain the arc channel at low voltages (below 15v or so) even with argon shield gas the arc will sometimes die.
It also allows the arc to start through paint and rust and to start without actual contact, between the work and electrode,

The output AC is low current and rides on the welder output voltage.
When the arc channel is large and well established the HF/AC component of the voltage drops to near zero.

If Simon718 wants, I could sketch a CD inverter schematic from memory.
It wouldn't be a perfect match for his, but might help him trouble shoot.
The thing might even run off of a 12v battery charger, enough to test.
Robert

robert, thanks very much for the offer, but hold off for the time being, i am going to get some leads made up to test it with a welder. will need to get some sort of adapter for the torch switch socket however, almost looks like a headphone jack?

 

[R Kraft]

To bad it won't run off of an AC welder, it makes them a lot nicer to use , on low amps.
Robert

 

[simon718]

had a quick play about earlier, connected it up to a 12v battery charger, the little light on the front didn't come on but the gas solenoid clicks when you press the red button on the front

 

[madkayaker]

that's a good start then not tempted then to connect to inverter?

 

[simon718]

no leads yet to try it with the inverter. quite afraid of damaging it too if there's a fault in the nifty

 

[madkayaker]

good point

 

[simon718]

i think the most sensible thing to do, is to keep my eyes open for a diesel powered DC stick welder to try it on, iv put some thought into it and there's no chance its getting plugged into the inverter, im not frying it its my favourite toy at the moment

 

[Jake SS]

i think the most sensible thing to do, is to keep my eyes open for a diesel powered DC stick welder to try it on, iv put some thought into it and there's no chance its getting plugged into the inverter, im not frying it its my favourite toy at the moment

I totally agree, It was not made to attach to an inverter, I would not risk it

Cheers
Jake

 

[zardoz]

Heh, That is not 5.5mm but 7/32".

And yes, we use Fahrenheit here.

Is there any brand name or logo on the sensor?

That's one of the things i love about America, it uses AF spanners and sockets and it uses Fahernheit for temparature. In the UK we use both metric and imperial. Also we use both C and F for temparature but most people dont even realize it. When its freezing we say "its below zero" when its hot we say "today it was in the eighties" (hot for us)

 

[R Kraft]

Where I live I just don't like it when the C and the F say the same thing.
Robert