Author Topic: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"  (Read 1438 times)

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 924
  • Karma: +11/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
I built my first experimental cheap power supply and it was a great success!

12 laptop chargers put together for 40V 51A.

http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline flyrod

  • High Voltage Enthusiast
  • *
  • Posts: 15
  • Karma: +0/-0
    • View Profile
I did blow up one Mosfet, but that was my own fault for paralleling one gate with too low of a resistance. 

So do these boards use the same pull up resisters for gate drive?
 

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 924
  • Karma: +11/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
5 minute stress test at full power. 1800 Watt peak input power.

http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline petespaco

  • High Voltage Experimenter
  • **
  • Posts: 52
  • Karma: +0/-0
    • View Profile
    • French Creek Valley Activities
Flyrod: "So do these boards use the same pull up resisters for gate drive?"
If you mean "do they use the same gate drive circuit as does the 1000 watt unit?"
Yes, for the 1800 watt unit that I have, at least.
The same 470 ohm 5 w wirewound resistor, 10K resistor, 12 volt zener  and FR307.

If you mean: "do all 4 gate drivers use the same pull up resistors for gate drive?"
The answer is still "yes".

Pete Stanaitis
---------------

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 924
  • Karma: +11/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
A new 2200 Watt power supply made from server power supplies, and with steady cameras :)

Test of it in a long induction heater run is being edited and will come online in a few days

http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 924
  • Karma: +11/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
/>
This test is being run at 36VDC and everything stays cool over a course of 10 minutes, I would say it can run stable at this power input. The 5 minute test at 40VDC showed resonant capacitors heating up.

Test is powered by the "2200 Watt server power supply for induction heating"
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline petespaco

  • High Voltage Experimenter
  • **
  • Posts: 52
  • Karma: +0/-0
    • View Profile
    • French Creek Valley Activities
That sure was a successful test.
    Is the "glowing" color that we see on the video that same as what you see in person?  Do you do anything special with the white balance of your video camera?

I am starting to work on establishing operational upper frequency limits on these devices.  I wonder how high they can go and still work okay.  Today, I certainly exceeded that number, so now I will have to "back up" to see where the real tripping point is.
So far, I hypothesize  that the data I gather from the 1000 watt unit will transfer directly to the 1800 and 2500 watt devices, since their gate circuits appear to be identical.  (Having said that, and seeing that two of three gate circuits are in parallel, I WILL have to verify that some day.)
By the way, I am using a cheap inductance meter for these measurements.  I think it is this one:
https://www.ebay.com/itm/LC100-A-High-Precision-Digital-Inductance-Capacitance-L-C-Meter-Tester-SMT-Clip/253959986062?hash=item3b2131db8e:m:mOpTSkV_q1oIM9pHKxVlPfw

Here's the record of this morning's test:
Objective:
  Determine the lower work coil inductance range for safe, useful operation of the popular 1000 Watt to 2500 Watt ZVS induction heaters.

Date: march 18, 2019

Subject for testing, March 18, 2019:
Testing a 10" U shaped work coil on the 1000 watt unit.

Method:
Make up a "one turn" coil to use as a worst case situation.  This coil is simply 25" of 1/4" OD copper tubing that is bent into a "U" shape, with about 3/4" between the arms.

Summary:
My initial conclusion is that the oscillation frequency observed during this test is somewhat beyond the safe or useful upper limit for this design.
  I hypothesize that the lower limit for work coil inductance is about 1.0 microhenry.
-----------------------------
Notes:

First I checked out the system using a "stock" 2" ID 6 Turn coil.  It ran, as it normally does,  at  about 6 amps of idle current.

Then I removed the 6 turn coil and replaced it with this "U" coil:
The measured inductance of this "U" coil is about 0.240 micro henry.
At present, the coil is actually several inches longer than 10.  I call it a "10 inch coil" because, once fully shaped, it would have a work area about 10 inches long for heat treating knife blades.
It has a spacing between the tubes of about 3/4".

For reference, these 1000 watt ZVS heaters come with coils that produce resonant frequencies between about 103 kHz and about 83 kHz.  These coils have measured inductances of about 1.05 to 1.38 micro henry.

Results:
The system  DID oscillate, but at about 154 kHz. 
And the gate waveform degraded significantly from the almost square shape it has with the "stock"  6 turn X 1 1/2" to 2" ID coils.  The signal almost looked like a sine wave with a slightly flattened top, both the leading AND the trailing edges.

  The idle current went to 16 amps.  I think this extra 10 amps is caused by the degraded gate signals causing the Mosfets to be running in linear mode for a good share of the time.  Also, the capacitors heated rapidly within a minute or so of "power on".



Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 924
  • Karma: +11/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
That sure was a successful test.
    Is the "glowing" color that we see on the video that same as what you see in person?  Do you do anything special with the white balance of your video camera?

It seems I have rather good UV filters on my phone and DSLR, as you actually see a red glowing work piece in the video and not a purple glow. It does however not filter it all, it does glow more bright on the video than in reality and I guess you have the same experience.

I am starting to work on establishing operational upper frequency limits on these devices.  I wonder how high they can go and still work okay.  Today, I certainly exceeded that number, so now I will have to "back up" to see where the real tripping point is.
So far, I hypothesize  that the data I gather from the 1000 watt unit will transfer directly to the 1800 and 2500 watt devices, since their gate circuits appear to be identical.  (Having said that, and seeing that two of three gate circuits are in parallel, I WILL have to verify that some day.)
By the way, I am using a cheap inductance meter for these measurements.  I think it is this one:
https://www.ebay.com/itm/LC100-A-High-Precision-Digital-Inductance-Capacitance-L-C-Meter-Tester-SMT-Clip/253959986062?hash=item3b2131db8e:m:mOpTSkV_q1oIM9pHKxVlPfw

Here's the record of this morning's test:
Objective:
  Determine the lower work coil inductance range for safe, useful operation of the popular 1000 Watt to 2500 Watt ZVS induction heaters.

Date: march 18, 2019

Subject for testing, March 18, 2019:
Testing a 10" U shaped work coil on the 1000 watt unit.

Method:
Make up a "one turn" coil to use as a worst case situation.  This coil is simply 25" of 1/4" OD copper tubing that is bent into a "U" shape, with about 3/4" between the arms.

Summary:
My initial conclusion is that the oscillation frequency observed during this test is somewhat beyond the safe or useful upper limit for this design.
  I hypothesize that the lower limit for work coil inductance is about 1.0 microhenry.
-----------------------------
Notes:

First I checked out the system using a "stock" 2" ID 6 Turn coil.  It ran, as it normally does,  at  about 6 amps of idle current.

Then I removed the 6 turn coil and replaced it with this "U" coil:
The measured inductance of this "U" coil is about 0.240 micro henry.
At present, the coil is actually several inches longer than 10.  I call it a "10 inch coil" because, once fully shaped, it would have a work area about 10 inches long for heat treating knife blades.
It has a spacing between the tubes of about 3/4".

For reference, these 1000 watt ZVS heaters come with coils that produce resonant frequencies between about 103 kHz and about 83 kHz.  These coils have measured inductances of about 1.05 to 1.38 micro henry.

Results:
The system  DID oscillate, but at about 154 kHz. 
And the gate waveform degraded significantly from the almost square shape it has with the "stock"  6 turn X 1 1/2" to 2" ID coils.  The signal almost looked like a sine wave with a slightly flattened top, both the leading AND the trailing edges.

  The idle current went to 16 amps.  I think this extra 10 amps is caused by the degraded gate signals causing the Mosfets to be running in linear mode for a good share of the time.  Also, the capacitors heated rapidly within a minute or so of "power on".

Thanks for doing these experiments with lower inductance work coils and the resulting frequencies and currents. As expected it heats up a lot from increased switching losses due to more time in the linear region, but also it did not explode! I had expected it to burn to ground from your U turn coil :)
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

High Voltage Forum


 


* Recent Topics and Posts

post Re: GDT Experiments
[Solid state Tesla coils]
Teravolt
March 20, 2019, 11:15:50 PM
post Re: GDT Experiments
[Solid state Tesla coils]
Thunderstruck
March 20, 2019, 09:07:04 PM
post Re: Keep or throw away ?
[Beginners]
Teravolt
March 20, 2019, 05:18:07 PM
post Re: New small SSTC
[Solid state Tesla coils]
Bambinz
March 20, 2019, 03:52:15 PM
post Re: New small SSTC
[Solid state Tesla coils]
Mads Barnkob
March 20, 2019, 01:23:52 PM
post Re: GDT Experiments
[Solid state Tesla coils]
T3sl4co1l
March 20, 2019, 01:18:29 PM
post Re: GDT Experiments
[Solid state Tesla coils]
Mads Barnkob
March 20, 2019, 01:06:24 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
March 20, 2019, 01:00:46 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Mads Barnkob
March 20, 2019, 12:41:22 PM
post Re: Keep or throw away ?
[Beginners]
Thunderstruck
March 19, 2019, 10:02:41 PM
post Re: Keep or throw away ?
[Beginners]
Hydron
March 19, 2019, 08:14:33 PM
post Re: Keep or throw away ?
[Beginners]
Teravolt
March 19, 2019, 05:12:03 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Experimentonomen
March 19, 2019, 01:32:32 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Mads Barnkob
March 19, 2019, 12:20:34 PM
post Re: Strange gdt waveforms
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
March 19, 2019, 12:15:22 PM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
Mads Barnkob
March 19, 2019, 10:46:50 AM
post Re: Keep or throw away ?
[Beginners]
Thunderstruck
March 19, 2019, 09:11:09 AM
post Re: Keep or throw away ?
[Beginners]
Mads Barnkob
March 19, 2019, 08:24:31 AM
post Re: Keep or throw away ?
[Beginners]
Teravolt
March 19, 2019, 01:51:51 AM
post Re: Keep or throw away ?
[Beginners]
Thunderstruck
March 18, 2019, 09:56:42 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
Weston
March 18, 2019, 07:55:52 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
March 18, 2019, 06:11:07 PM
post Re: Strange gdt waveforms
[Dual Resonant Solid State Tesla coils]
Hydron
March 18, 2019, 02:27:35 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
Uspring
March 18, 2019, 12:52:35 PM
post Re: Strange gdt waveforms
[Dual Resonant Solid State Tesla coils]
FilipŠebík
March 18, 2019, 12:22:58 PM
post New small SSTC
[Solid state Tesla coils]
Bambinz
March 18, 2019, 11:46:18 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Bambinz
March 18, 2019, 11:29:02 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
Mads Barnkob
March 18, 2019, 10:35:04 AM
post Re: Strange gdt waveforms
[Dual Resonant Solid State Tesla coils]
Marty
March 18, 2019, 05:32:43 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Experimentonomen
March 17, 2019, 09:13:47 PM
post Re: DRSSTC Driver Logic
[Dual Resonant Solid State Tesla coils]
Netzpfuscher
March 17, 2019, 04:08:33 PM
post Re: WTB: Large Heatsink with a Baseplate at least 10mm thick
[Sell / Buy / Trade]
Phoenix
March 17, 2019, 02:46:44 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
flyglas
March 17, 2019, 02:21:45 PM
post Re: DRSSTC Driver Logic
[Dual Resonant Solid State Tesla coils]
Laci
March 17, 2019, 01:54:47 PM
post Re: WTB: Large Heatsink with a Baseplate at least 10mm thick
[Sell / Buy / Trade]
Mads Barnkob
March 17, 2019, 10:15:16 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
FilipŠebík
March 17, 2019, 09:33:50 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
Teravolt
March 17, 2019, 05:32:48 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
Thunderstruck
March 17, 2019, 02:39:25 AM
post WTB: Large Heatsink with a Baseplate at least 10mm thick
[Sell / Buy / Trade]
Phoenix
March 16, 2019, 10:06:39 PM
post Re: Large Ferrite Core with IGBT-Brick Driver
[Transformer (ferrite core)]
rikkitikkitavi
March 16, 2019, 08:35:51 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
Weston
March 16, 2019, 08:04:52 PM
post Re: cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
flyglas
March 16, 2019, 06:44:14 PM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
FilipŠebík
March 16, 2019, 09:57:55 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
Thunderstruck
March 16, 2019, 09:40:55 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
FilipŠebík
March 16, 2019, 08:57:54 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
Thunderstruck
March 16, 2019, 08:46:24 AM
post Re: Which varnish to use to coat the Secondary?
[Solid state Tesla coils]
FilipŠebík
March 16, 2019, 08:27:24 AM
post Re: UD 2.7C Build
[Dual Resonant Solid State Tesla coils]
Thunderstruck
March 16, 2019, 07:35:58 AM
post GDT Experiments
[Solid state Tesla coils]
Thunderstruck
March 16, 2019, 06:32:36 AM
post cute-qcw Tesla Coil
[Dual Resonant Solid State Tesla coils]
Weston
March 16, 2019, 06:01:44 AM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30