Author Topic: My mosfet driverless mosfet slayer exciter with adjustable power (not working)  (Read 1936 times)

Offline Jun

  • High Voltage Enthusiast
  • *
  • Posts: 27
  • Karma: +1/-0
    • View Profile
Hi. I'm fairly new to electronics but I decided to try and make a mosfet slayer exciter circuit. Most of the mosfet slayer exciter uses mosfet driver to turn on and off the gate of the mosfet, but since I don't have an access to it, I decided to use BJT(TIP41) to turn on the gate. I came up with the circuit my own and that's probably why it doesn't work :< Anyways, the potentiometer is tuned to 4.2V at mosfet gate and when I turn it on, the mosfet is always shorted and draws about 1A (always shorted). I probed the circuit and noticed that the feedback from the secondary ground is probably not enough to turn off the base of BJT and thats why it's constantly shorting the mosfet. My TIP41 works well with the BJT slayer exciter so secondary feedback should be able to turn off the BJT right?

I spent hours trying to troubleshoot and researching. Please help me out!

Offline ritaismyconscience

  • High Voltage Technician
  • ***
  • Posts: 163
  • Karma: +4/-0
    • View Profile
try it on falstad.com/circuit to see if circuit works as intended.

Offline Jun

  • High Voltage Enthusiast
  • *
  • Posts: 27
  • Karma: +1/-0
    • View Profile
Ok I'll give it ago!

Offline Jun

  • High Voltage Enthusiast
  • *
  • Posts: 27
  • Karma: +1/-0
    • View Profile
I've tried, but I still can't get it to resonate. I can't get the transformer to operate right. There's no option to change the secondary.

Offline SteveN87

  • High Voltage Enthusiast
  • *
  • Posts: 47
  • Karma: +4/-0
  • FPGA, Software Defined Radio, HV (mainly flyback)
    • View Profile
I've never used online simulators before - but it says "3 bad connections" at the bottom!

Re the secondary - you can set the primary inductance, the turns ratio and the coupling coefficient only.
If you know the secondary inductance but not the turns ratio, you can calculate it as follows:

turns ratio = SQRT(secondary inductance/primary inductance)

The coupling coefficient will probably be less than 0.5 for a slayer coil.

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 379
  • Karma: +12/-0
    • View Profile
In that online simulation, mind the polarity of the transformer windings.
I don't see any indicator dots, and am not aware of any convention in the absence of dots.
Not sure it matters in the case you showed, with no feedback from secondary to primary side.

I bet the "3 bad connections" are associated with red dots in the rendering.  One problem with electric circuit CAD in the real world, is connection problems that are invisible in the graphical schematic.  One needs to check the netlist, or in some cases get an acceptable result from simulation that is based on netlist.

Took a look at the falstad.com site, and must applaud the choice to move dots in the direction of conventional current (little positive charges).  Downward in the collector and emitter wires here, following the arrow.  Newbies will find it easier to follow the literature when they let go of urge to think in terms of electron drift, which is a pesky detail discovered long after electric circuit theory.


« Last Edit: May 10, 2020, 05:04:12 PM by klugesmith »

Offline ritaismyconscience

  • High Voltage Technician
  • ***
  • Posts: 163
  • Karma: +4/-0
    • View Profile
Draw a wire between one of the red dots and one of the other connections to fix it.

It doesn't automatically connect if you just place a component on top of a wire, you still need to connect it manually

Offline Jun

  • High Voltage Enthusiast
  • *
  • Posts: 27
  • Karma: +1/-0
    • View Profile
Hi guys. Sorry for the late reply. I've been busy with my assignments. And I realised what was wrong with my setup. The secondary was connected to feedback before when I was using regular slayer exciter, but somehow disconnected and that's why it was constantly shorting mosfet. I fixed the connection and changed few things and now it works fine. Thanks for the support on the simulation side. I now know somewhat on how to use circuit simulation.

High Voltage Forum


 


* Recent Topics and Posts

post Re: Capacitor testing
[Voltage Multipliers]
johnf
Today at 09:33:01 AM
post Re: UD2.7 GDT problem
[Dual Resonant Solid State Tesla coils (DRSSTC)]
endi007
Today at 08:46:23 AM
post Re: UD2.7 GDT problem
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
Today at 08:10:02 AM
post Re: CT current phase leading by 60°
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
Today at 08:03:04 AM
post Re: UD2.7 GDT problem
[Dual Resonant Solid State Tesla coils (DRSSTC)]
endi007
Today at 07:41:29 AM
post Re: Capacitor testing
[Voltage Multipliers]
MRMILSTAR
Today at 05:42:57 AM
post Capacitor testing
[Voltage Multipliers]
abstruse1
Today at 05:02:21 AM
post CT current phase leading by 60°
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Karl Fischer
August 04, 2021, 11:46:10 PM
post IGBT Desaturation Detector
[Electronic Circuits]
TMaxElectronics
August 04, 2021, 06:03:32 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
johnnyzoo
August 04, 2021, 11:03:33 AM
post UD2.7 GDT problem
[Dual Resonant Solid State Tesla coils (DRSSTC)]
endi007
August 04, 2021, 09:18:03 AM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
August 03, 2021, 08:59:22 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MrScrOggs
August 03, 2021, 06:41:57 PM
post Re: Flyback secondary burnout
[Voltage Multipliers]
johnnyzoo
August 03, 2021, 06:31:34 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
johnnyzoo
August 03, 2021, 06:16:50 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MrScrOggs
August 03, 2021, 04:29:02 PM
post Motorcycle Music
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Transgarp
August 03, 2021, 01:50:26 PM
post Re: Up to 9 half-bridges of FS35R12 IGBTs in parallel, per board...
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Da_Stier
August 03, 2021, 10:35:58 AM
post Re: Up to 9 half-bridges of FS35R12 IGBTs in parallel, per board...
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
August 03, 2021, 07:55:07 AM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
August 02, 2021, 10:40:00 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
Mads Barnkob
August 02, 2021, 09:06:52 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
SalinsLV
August 02, 2021, 08:34:06 PM
post Flyback secondary burnout
[Voltage Multipliers]
abstruse1
August 02, 2021, 05:47:02 PM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
Mads Barnkob
August 02, 2021, 08:07:25 AM
post Re: VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
August 02, 2021, 05:44:35 AM
post VTTC Arcs From Feedback Coil
[Vacuum Tube Tesla Coils (VTTC)]
MrScrOggs
August 01, 2021, 09:16:20 PM
post Re: UD2.7C and news coil 150khz 70cm
[Dual Resonant Solid State Tesla coils (DRSSTC)]
JCF
August 01, 2021, 03:57:42 PM
post Re: UD2.7C and news coil 150khz
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
August 01, 2021, 02:10:03 PM
post UD2.7C and news coil 150khz 70cm
[Dual Resonant Solid State Tesla coils (DRSSTC)]
JCF
August 01, 2021, 12:06:46 PM
post Re: Teardown of Kathrein 1800/900 MHz Antenna For Mobile Phone Base Station
[Radio Frequency]
Da_Stier
July 31, 2021, 09:23:10 PM
post Re: Teardown of Kathrein 1800/900 MHz Antenna For Mobile Phone Base Station
[Radio Frequency]
Mads Barnkob
July 31, 2021, 08:52:44 PM
post Re: Teardown of Kathrein 1800/900 MHz Antenna For Mobile Phone Base Station
[Radio Frequency]
Da_Stier
July 31, 2021, 01:23:07 PM
post Re: CW Help -- too much info to digest
[Voltage Multipliers]
abstruse1
July 31, 2021, 03:15:04 AM
post Re: What is BPS?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Felix B.
July 30, 2021, 11:53:25 PM
post Re: Teardown of Kathrein 1800/900 MHz Antenna For Mobile Phone Base Station
[Radio Frequency]
Da_Stier
July 30, 2021, 09:11:33 PM
post Re: What is BPS?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
July 30, 2021, 08:16:05 PM
post Re: My X-Ray Machine
[X-ray]
neukyhm
July 30, 2021, 06:42:54 PM
post Teardown of Kathrein 1800/900 MHz Antenna For Mobile Phone Base Station
[Radio Frequency]
Mads Barnkob
July 30, 2021, 02:42:24 PM
post Re: Toslink eagle library (FCR6842031R)
[Printed Circuit Board]
Da_Stier
July 30, 2021, 11:44:23 AM
post Re: What is BPS?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
PEDRO HENRIQUE
July 30, 2021, 06:16:06 AM
post Re: CW Help -- too much info to digest
[Voltage Multipliers]
davekni
July 30, 2021, 04:57:44 AM
post Re: Need second opinion on tesla coil capacitors
[Spark Gap Tesla Coils (SGTC)]
davekni
July 30, 2021, 04:45:12 AM
post Re: CW Help -- too much info to digest
[Voltage Multipliers]
abstruse1
July 30, 2021, 03:37:44 AM
post Re: Toslink eagle library (FCR6842031R)
[Printed Circuit Board]
Twospoons
July 30, 2021, 12:08:11 AM
post Toslink eagle library (FCR6842031R)
[Printed Circuit Board]
br0
July 29, 2021, 09:35:45 PM
post Re: CW Help -- too much info to digest
[Voltage Multipliers]
MRMILSTAR
July 29, 2021, 05:16:39 AM
post Re: CW Help -- too much info to digest
[Voltage Multipliers]
abstruse1
July 29, 2021, 03:38:23 AM
post Re: Grounding VTTC
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
July 28, 2021, 08:31:50 PM
post Re: Grounding VTTC
[Vacuum Tube Tesla Coils (VTTC)]
SalinsLV
July 28, 2021, 08:07:10 PM
post Re: Tesla Coil Music
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Max
July 28, 2021, 05:17:06 PM

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