Author Topic: UD2.7 dual Purpose Use  (Read 1480 times)

Offline FonziDaytona

  • High Voltage Experimenter
  • **
  • Posts: 62
  • Karma: +0/-0
    • View Profile
Re: UD2.7 dual Purpose Use
« Reply #20 on: September 26, 2022, 07:55:31 PM »
I wonder if I can disable UVLO, at startup, and then re-enable? Or, use a switch instead of a jumper on the Interruptor output to toggle?

-Matt

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1895
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: UD2.7 dual Purpose Use
« Reply #21 on: September 27, 2022, 03:12:49 AM »
Quote
I wonder if I can disable UVLO, at startup, and then re-enable?
Might help, but still leaves power-up state of OCD FF indeterminate.  Random chance FF will power up enabled.

Quote
Or, use a switch instead of a jumper on the Interruptor output to toggle?
Yes, that is what I was trying to suggest.  A normally-closed push-button switch would make starting easiest.  Just a push of the button rather than toggling a switch off and then back on.
David Knierim

Offline FonziDaytona

  • High Voltage Experimenter
  • **
  • Posts: 62
  • Karma: +0/-0
    • View Profile
Re: UD2.7 dual Purpose Use
« Reply #22 on: October 12, 2022, 05:11:46 PM »
Okay, so I’ve been running this for a little now and it seems to be doing the job, but I’ve found that my IGBT gate drive resistors (5.1ohm .5watt) are getting extremely hot, and I don’t understand why.

My math:

Cm300dy-12nf has 1200nC per the data sheet. Current needed should be:
1200nC*35khz = 42mA, right? I^2R heating should only be 9mW? I don’t see why my .5w resistors are getting so hot…

-Matt
« Last Edit: October 12, 2022, 05:15:33 PM by FonziDaytona »

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1895
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: UD2.7 dual Purpose Use
« Reply #23 on: October 13, 2022, 05:07:57 AM »
Quote
Okay, so I’ve been running this for a little now and it seems to be doing the job, but I’ve found that my IGBT gate drive resistors (5.1ohm .5watt) are getting extremely hot, and I don’t understand why.

My math:

Cm300dy-12nf has 1200nC per the data sheet. Current needed should be:
1200nC*35khz = 42mA, right? I^2R heating should only be 9mW? I don’t see why my .5w resistors are getting so hot…
First, induction heating etc. applications typically run much higher duty cycles than DRSSTC.  That is why DRSSTC's have less issue with gate resistor heating.

Analog simulation is one way to see details of gate resistor power dissipation.  For simple approximations, two changes from your math:

Gate charge of 1200nC is for 0-15Vge swing.  If UD2.7 is being fed 24V, then Vge is swing -24V to +24V (48Vpp rather than 15Vpp).  Gate charge will be roughly proportional to Vpp, so 1200nC * 48V / 15V =  3840nC.  3840nC * 35kHz = 134mA.  This presumes gate resistor is paralleled by a diode, so conducting current only during Vge rising edges.

134mA is average current.  RMS current is much higher.  Presume that UD2.7 output resistance and GDT wire resistance are negligible compared to gate resistor.  Presume no internal brick gate resistors.  (I don't see any listed in specification for Cm300dy-12nf.)  Also presume instant UD2.7 output switching.  With those assumptions, average voltage across gate resistor during current flow is 24V (48V down to 0V during each Vge rising edge).  So resistor power is 134mA * 24V = 3.2W (at 100% duty cycle).

The above assumptions end up being worst-case.  Some of that 3.2W per gate will be dissipated within UD2.7 output FETs.  (A higher percentage of the additional 3.2W/gate power from falling edges is dissipated within UD2.7 output FETs.)

I've concluded that bricks are overkill for most high-duty-cycle applications, since they require high gate drive power.  TO247 IGBTs are a better fit for such uses, or small bricks.  0-15Vge drive also works better for such, presuming layout is clean enough to make negative Vge unnecessary.  (And presuming no internal gate resistors, which then require negative Vge to turn off sufficiently fast.)

Good luck with modifications to fix gate resistor power issues!
David Knierim

Offline FonziDaytona

  • High Voltage Experimenter
  • **
  • Posts: 62
  • Karma: +0/-0
    • View Profile
Re: UD2.7 dual Purpose Use
« Reply #24 on: October 13, 2022, 04:47:02 PM »
Hi David,

I knew I was missing a few things :-)

That would explain the heating, then.

I ordered some 3W 5ohm resistors…I should be able to run at a little lower frequency (30khz) and be within their ratings. I may also incorporate my Interruptor to drop the on time down a bit. I had originally planned to do this for helping with current limit if my PSU winds up exceeding expectations.

Thanks!
Matt

High Voltage Forum

Re: UD2.7 dual Purpose Use
« Reply #24 on: October 13, 2022, 04:47:02 PM »

 


* Recent Topics and Posts

post Re: IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
RoamingD
Today at 06:56:51 AM
post Re: IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alexhanyuan
November 25, 2022, 11:28:15 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 25, 2022, 12:05:50 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 25, 2022, 07:53:52 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 24, 2022, 08:08:48 AM
post Re: EEFL backlight circuits
[Light, Lasers and Optics]
klugesmith
November 24, 2022, 07:26:49 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
davekni
November 24, 2022, 03:02:11 AM
post Re: Solid State “rheostat” that will withstand high electrostatic fields
[General Chat]
AkashaStar
November 24, 2022, 02:25:42 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 24, 2022, 01:45:33 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
John123
November 23, 2022, 11:27:18 PM
post Stepper motor drive without switching
[Electronic Circuits]
klugesmith
November 23, 2022, 10:23:07 PM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
Twospoons
November 23, 2022, 09:29:01 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 23, 2022, 08:45:37 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
davekni
November 23, 2022, 04:44:20 AM
post Air cored inductors proximity to conductive objects
[General Chat]
John123
November 23, 2022, 01:10:17 AM
post Re: Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
November 22, 2022, 08:40:19 PM
post Re: Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
Da_Stier
November 22, 2022, 08:22:09 PM
post Re: Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
Kirby4life
November 22, 2022, 08:45:06 AM
post Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
RickNitro
November 22, 2022, 08:36:11 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 22, 2022, 06:42:31 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 22, 2022, 06:40:32 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 22, 2022, 04:53:40 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 22, 2022, 02:17:08 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 21, 2022, 11:03:04 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 21, 2022, 09:55:02 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 21, 2022, 03:09:26 PM
post Re: Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
LoOdaK
November 21, 2022, 09:38:22 AM
post Re: Trichel pulses
[Electronic Circuits]
klugesmith
November 20, 2022, 10:05:15 PM
post Trichel pulses
[Electronic Circuits]
haversin
November 20, 2022, 09:48:37 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 20, 2022, 07:17:36 PM
post Re: Some questions about my first drsstc.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
mthome4
November 20, 2022, 02:28:22 PM
post Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
November 20, 2022, 02:03:49 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 20, 2022, 10:00:13 AM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 20, 2022, 05:13:12 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
davekni
November 20, 2022, 05:08:31 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
alan sailer
November 20, 2022, 01:27:00 AM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
davekni
November 19, 2022, 10:12:14 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 19, 2022, 09:57:35 PM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
prabhatkumar
November 19, 2022, 09:50:23 PM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
davekni
November 19, 2022, 08:26:45 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 19, 2022, 06:53:17 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 19, 2022, 06:05:47 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 19, 2022, 05:34:46 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 19, 2022, 02:30:04 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
AkashaStar
November 19, 2022, 01:56:10 PM
post Re: Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dru
November 19, 2022, 08:03:56 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 19, 2022, 06:38:00 AM
post Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
prabhatkumar
November 19, 2022, 05:37:09 AM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
davekni
November 19, 2022, 03:59:56 AM
post Re: Non-laser pointer
[Light, Lasers and Optics]
klugesmith
November 19, 2022, 03:56:32 AM
post Re: Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
November 19, 2022, 03:36:20 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 19, 2022, 03:26:48 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 19, 2022, 12:40:33 AM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
AstRii
November 18, 2022, 09:32:33 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 18, 2022, 05:48:00 PM
post Re: Audio Modulated CRT Flyback Transformer Loud Sparks
[Transformer (Ferrite Core)]
John123
November 18, 2022, 03:49:12 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 18, 2022, 02:56:49 PM
post IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
RoamingD
November 18, 2022, 01:44:38 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 18, 2022, 11:38:44 AM
post Non-laser pointer
[Light, Lasers and Optics]
klugesmith
November 18, 2022, 10:05:29 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 18, 2022, 06:54:55 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Twospoons
November 18, 2022, 06:29:23 AM
post Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dru
November 18, 2022, 06:10:52 AM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 18, 2022, 05:53:15 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 18, 2022, 05:21:52 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 18, 2022, 04:00:04 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
alan sailer
November 17, 2022, 10:24:35 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 17, 2022, 08:30:00 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
klugesmith
November 17, 2022, 07:28:16 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 17, 2022, 03:38:00 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 17, 2022, 04:03:51 AM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
davekni
November 17, 2022, 03:57:40 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 17, 2022, 03:26:32 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 16, 2022, 11:23:37 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
alan sailer
November 16, 2022, 08:00:54 PM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
John123
November 16, 2022, 05:09:00 PM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
MRMILSTAR
November 16, 2022, 04:57:27 PM
post TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 16, 2022, 03:27:06 PM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
John123
November 16, 2022, 03:16:13 PM
post Bluetooth to aux for plasma speaker circuits
[Electronic Circuits]
John123
November 16, 2022, 03:00:54 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 16, 2022, 11:43:49 AM
post Re: Electrical resistance cooking
[Laboratories, Equipment and Tools]
klugesmith
November 16, 2022, 09:00:46 AM
post Re: Electrical resistance cooking
[Laboratories, Equipment and Tools]
klugesmith
November 16, 2022, 08:53:42 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 16, 2022, 05:45:24 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
alan sailer
November 15, 2022, 08:17:46 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 15, 2022, 07:25:04 PM
post Re: Yet another UD2.x pulse skipper
[Dual Resonant Solid State Tesla coils (DRSSTC)]
hammertone
November 14, 2022, 12:26:19 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 14, 2022, 04:57:41 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 14, 2022, 12:32:54 AM
post Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 13, 2022, 11:06:55 PM
post Re: QO-100 / EShail 2 Uplink amplifier development adventures
[Radio Frequency]
Da_Stier
November 13, 2022, 06:32:11 PM
post Re: Yet another UD2.x pulse skipper
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
November 13, 2022, 04:41:20 PM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
November 13, 2022, 02:38:41 PM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
MRMILSTAR
November 13, 2022, 05:23:09 AM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
thedark
November 12, 2022, 10:39:21 PM
post Re: Yet another UD2.x pulse skipper
[Dual Resonant Solid State Tesla coils (DRSSTC)]
hammertone
November 12, 2022, 12:45:16 PM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
klugesmith
November 12, 2022, 05:44:35 AM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
thedark
November 12, 2022, 05:30:10 AM
post Re: Yet another UD2.x pulse skipper
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
November 12, 2022, 01:11:31 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Twospoons
November 12, 2022, 12:42:54 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 
SimplePortal 2.3.6 © 2008-2014, SimplePortal