Induction brass annealer redux

[ST42]

itchyTF, the power supply does have a rheostat to adjust voltage. Would increasing the voltage allow additional current?

Bob2650, My coil specs are as follows,
Inside diameter, 1.075” or 27.13mm
Height 1.49” or 38mm’s
The coil is 7.5 turns.

 

[ST42]

This link talks about the power and amp limit of the MGNZ board. My draw is 9.8A without a case in the coil.

48V power supply setup | Mgnz Makes

How to setup the 48V power supply for induction annealing

www.mgnz-makes.com

 

[itchyTF]

itchyTF, the power supply does have a rheostat to adjust voltage. Would increasing the voltage allow additional current?

Bob2650, My coil specs are as follows,
Inside diameter, 1.075” or 27.13mm
Height 1.49” or 38mm’s
The coil is 7.5 turns.

I believe so. If you ran 40v at 600W you should be able to draw 15A. This depends on the PS design. 9.8A seems like a lot for idling current. Try it.

 

[Bob2650]

8 1/2 turns is the magic number.
Or, at least it was a few years ago.
The inside diameter should be about 1 1/8 inches, your close enough. 3/4" Schedule 40 PVC pipe is the preferred form to wind the coil on.

 

[itchyTF]

Are you using 1/8” or 1/4” tubing?

 

[Ron Blain]

At a glance and looking at your symptoms would be that when you insert a cartridge the heating coil inductance changes which is to be expected. The change is enough to cause oscillation to stop. The ZVS board is driven usually by two MOSFETs driving your induction coil. When oscillation ceases only one MOSFET will be conducting. This may be causing an overcurrent condition causing a shutdown. Less seeing a complete system schematic and the Arduino code it's hard to call but I would focus on induction coil diameter, your copper pipe diameter and number of turns on the coil. This is purely a guess. You could try powering only the ZVS module less everything else and see if the module works. Less a scope to monitor the induction coil at failure it's hard to tell what's going on in the process.

Purely a guess on my part.

Ron

 

[rsbhunter]

Picture of how I cool my coil...hoses go to small pump in a water container...I can hold the coil as it anneals....rsbhunter (tape around unit holds plate to keep unit from rocking)

 

[ST42]

Gents,
Well I'm back at working the annealer. My coil is made from 1/8" copper tubing that I carefully wrapped around schedule 40 pipe. As you face the machine it looks like 8 coils, but is actually 7.5. Hopefully that makes sense.
Today I took the following readings from my equipment. These are with both PS's set at maximum.
1. Power Supply output 48.7 volts at idle. Annealing, no Case 48.4 volts
2. Power Supply ( 12 volt supply module) 12.3volts
3. ZVS power supply terminal reading with the Annealer running, No Case in the coil. 47.2 Volts
4. ZVS at idle, 0 volts.
5. ZVS with a case in the coil, Voltage was wildly fluctuating, almost impossible to see the readings. What I could make out was a range from 2.3 - 28.7 Volts. Again an instant Coil Fault Message.

As a reminder. I have changed out the ZVS twice along with the SSR twice.

Thank you all for your conitued help on this.

ST42

 

[itchyTF]

Gents,
Well I'm back at working the annealer. My coil is made from 1/8" copper tubing that I carefully wrapped around schedule 40 pipe. As you face the machine it looks like 8 coils, but is actually 7.5. Hopefully that makes sense.
Today I took the following readings from my equipment. These are with both PS's set at maximum.
1. Power Supply output 48.7 volts at idle. Annealing, no Case 48.4 volts
2. Power Supply ( 12 volt supply module) 12.3volts
3. ZVS power supply terminal reading with the Annealer running, No Case in the coil. 47.2 Volts
4. ZVS at idle, 0 volts.
5. ZVS with a case in the coil, Voltage was wildly fluctuating, almost impossible to see the readings. What I could make out was a range from 2.3 - 28.7 Volts. Again an instant Coil Fault Message.

As a reminder. I have changed out the ZVS twice along with the SSR twice.

Thank you all for your conitued help on this.

ST42

Did you try reducing the voltage?

 

[ST42]

Yes, I have tried that as well. I will check voltage on it now.

 

[ST42]

I dropped the PS voltage to minimum.
1. PS at idle, 45.4 V
2. ZVS, annealing, no case, 44.2 V
3. ZVS at idle, 0 V
4. ZVS annealing with case in the coil, 3.5 V and then failure. Again it was just a flash on the voltmeter.

 

[ST42]

Here are a few photos of my ZVS as installed.

 

[ST42]

Forgot the coil,

 

[ST42]

Here is an interesting development. I ran the annealer with a long screw driver just at the top entrance to the coil. It annealed it!!! The blade wasn't in the coil, but it was suspended just at the top opening of the coil.... I have no idea on that???

 

[itchyTF]

With the voltage lowered, what was the idle current?

 

[ST42]

I can only see amps when the unit is actually annealing. The voltage at the ZVS at idle is zero.

 

[itchyTF]

Here is an interesting development. I ran the annealer with a long screw driver just at the top entrance to the coil. It annealed it!!! The blade wasn't in the coil, but it was suspended just at the top opening of the coil.... I have no idea on that???

The magnetic field goes beyond the coil. Try that with a scrap brass case. You may need gloves or something but don’t use any ferrous metal tools to hold it. Note the current as you lower the case into the coil. Start above the coil.

 

[ST42]

I'm wondering if the coil insulation is not really insulating the coil wraps from one another?

 

[itchyTF]

What I meant by idle current was annealing without a case.

 

[itchyTF]

If you had a shorted turn it would show up with or without a case.