Author Topic: Troubleshooting my first SSTC  (Read 316 times)

Offline Seb555

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Troubleshooting my first SSTC
« on: April 19, 2019, 08:14:08 AM »
Hello everyone!
This is my first post. Just so you know, I am a junior in high school, and I have a passion for electronics! Ok, so for the last few months I've been working on a SSTC. I've learned a lot from this website: https://www.loneoceans.com/labs/sstc2/ and I've based the bridge of my tesla coil off of this schematic: Since I want to eventually upgrade to a drsstc though, for the driver and logic circuitry, I've based it off of Steve's DRSSTC-1 and OneTesla's schematic (which can be found for free via google search): I've simplified my design slightly by omitting the OCD, and my setup for the flip-flop is slightly different (in my design the PRE is just connected to 5V). For feedback, I was initially just going to use an antenna, but after that failed to work, I decided to use a CT. Unlike Steve's design, my current transformer takes the signal off of the secondary (1 turn of the secondary ground wire to ~60 turns 24GA magnet wire). Also, my feedback circuit looks more like Guangyan's schematic (the first one) with the 0.1nF cap omitted and a 100k resistor and 470pF cap added to filter the signal right before the hex inverters. I've tested the GDT (which I have revised three times now) along with the logic circuitry; the output waveform on my scope (measured straight off of the IGBTs) looks like this: . For an interrupter, I'm using an Arduino. The program outputs a 100Hz square wave with adjustable duty cycle via a potentiometer (in the future, I'm hoping to upgrade to something that can play music!). I'm also using fiber optic isolation. Here is a few more pictures of my setup:
Overall:

The logic board/GDT: (outside assembly)

The current transformer:

The half bridge: (seen inside assembly with logic board and GDT)

The power supply: (outside assembly)

All connections have been made via soldering on perf board. My overall schematic on easyEDA looks like this: (hopefully the pdf comes out ok)
* Schematic_Tesla-Coil_AnalogInterputorWithLevelMeter_20190419011744.pdf
So for the last few days, I've been troubleshooting my coil - things like this never work on the first try! Because I don't have a variable/isolation transformer I can't use my scope while running it. So far, I've only lost one IGDT though - when I tried using a 555 oscillator to drive the feedback signal. Currently, all I'm trying to do is get the tesla coil to do anything! In one of the attached photos of my setup, a florescent bulb is visible - I've been using this to monitor if the coil is working or not. At first, all I got was a short blink every time I flicked the power on (nothing with the interrupter). Then, I tried increasing the coupling with more primary turns. After I did this, I tried powering the bridge with a 20V laptop power supply and nothing happened. Then, I decided to just go for full power and soldered on the connections to mains. Again, nothing happened. Then I though I should try switching the polarity/phasing of the primary. When I did this, the bulb flashed on (dimly) and remained on (with interrupter signal) after I had power up the coil! During this test, I had used an aligator clip wire (connected to the ground prong on the power cord receptacle) as a target for the arks. When I turned up the interrupter to around 10% duty there was a ZAPP and the tesla coil discharged to the aligator clip. Afterwards, I couldn't even get the bulb to flash on again for a while. During this time, I tried testing for shorts across the IGBTs but they seemed intact. Also, the fuse hadn't blown either. I tried testing the coil again a few times (after each failure I checked the IGBTs and the fuse with my meter) to no success. However, on the third attempt - after pushing in the power cord to make sure there was a good connection - I got arks! It was amazing; at the push of a button I could hear and SEE 100Hz at the end of the breakout point! However, after simply turning down the interrupter duty and then trying to turn it back up again, the coil simply stopped working.  :'( Again, the fuse was fine, and there were no shorts across the IGBTs. After trying to test the TC again, I couldn't even get the bulb to flash. I'm not sure if that lucky third test even had anything to do with pushing in the power cord - I think it might have something to do with the feedback or potentially something is overheating and shutting off (like the voltage regulators).
At this point, I just though: "oh there was that High Voltage Forum I saw the other day," and I made an account so that I could post my dilemma. I understand that the troubleshooting process might take awhile (in my experience it's often longer than the initial building process!), but I was just hoping you guys might have some tips or feedback that could help me go in the right direction.  ;)

Offline Fumeaux

  • High Voltage Experimenter
  • **
  • Posts: 59
  • Karma: +7/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #1 on: April 19, 2019, 10:03:59 AM »
Hi and Welcome to this forum!

One can tell that you much time into this already. Im sure you know some basics of troubleshooting. Not too long ago there was a similar question so I'm just gonna recycle my answer:

Driver:
Use a multimeter to verify that GND and 12V isn't shorted (large cap might look like a short), or use a short-proof powersupply (like a computer psu), or . Disconnect the GDT and hook the 12V up. Then use a multimeter to test the voltages (5V, 12V). Then apply a squarewave (at your wanted frequency) to the feedback and use an oscilloscope to see if the signal gets processed correctly (hex inverter, ucc input and then the ucc output). Then attach the GDT and make sure that the mosfets/igbts get the drive signal.

Further testing:
Make sure that the mosfets don't turn on at the same time/phasing. Test if you have the mosfets connected the right way. Then apply a low voltage (12V - 30V) to the bridge for a short time and check if the mosfets are warm. If not everything works fine. Then you can hook the bridge to the primary and make sure that it doesn't draw too much current. Then add the secondary and it should give you the first arks. (At this point you probably can increase the voltage, but always be careful and check if anything gets warm (heatsink, caps, chips,...) and never let it run too long without checking if anything gets hot)

Feedback:
Then you can add your feedback (antenna/secondary base transformer) and try it out. You might need to change the phasing if it doesn't work the first time.

Honestly I think your board look great, but you will most likely need a bigger heatsink. Those Mosfets will heat up quite a bit with this small heatsink. Just adding a fan will probably be not enough.

Some questions:
  • Did you test the frequency of your secondary coil with a function generator?
  • Did you calculate the Impedance of your Primary coil?
  • Do you have a variac?

I just want to add that in the beginning its usually a better idea to just follow one design, but creating your "own" curcuit gives better reward. That's for sure.

The second point I want you to know concernes your physicas coil (primary and secondary). Did you use JavaTC or just use some measurements that seemed fine? If you didn't calculate lets say your primary inductance and the impedance of it you could have really bad output performance, or you IGBTs could die all the time. And of course here is Mads design guide: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/ not everything you can find there is also relevant for SSTC's, but most of it is. For example a low inducatance bus isn't that important. On the other hand the secondary design part is. You just have to decide what you need/want and what not.
Also it is quite interesting to know about all that other stuff too.
« Last Edit: April 19, 2019, 10:11:15 AM by Fumeaux »

Offline Seb555

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #2 on: April 19, 2019, 07:46:08 PM »
Thank you so much for your feedback!  :D
I have looked at a few of the pages on the link you provided (http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/), and I have used javaTC for my coil, but I'm not sure what sort of values I should be looking for. My resonant frequency is ~125.1kHz, secondary Q is 111, and reactance at resonance is 73057 (the page on secondary design recommends 50kOhms). Also, it seems strongly advised to prevent any overlaps whatsoever in the secondary windings. I unfortunately have a few overlaps in my secondary. For the primary, I have 12 turns of 14AWG ~1.5cm away from the secondary. My coupling coefficient is 0.316k.
Here is my javaTC txt file:
* Seb555JavaTCFile.txt

Here are a few more photos of the physical setup:




In regards to testing the driver etc, I had done so before I assembled everything together. The output signal across the IGBTs from my GDT looked good, but I will test it again as I guess it might have been damaged. My multimeter has a temperature probe, so I will try testing the temperature of the voltage regulators and IGBTs.
Also, do you think it would be worthwhile to try adjusting the height of the toroid. Currently, it's about 4cm above the last secondary winding.
In addition, I may also try adding an antenna again in the case that my CT is not functioning properly.

EDIT:
I did not find that either the 12V rail or the 5V rail was shorted to ground.

Also, I just tested the coil again. The purpose of my test was to see if the 12V regulator was heating up at all (an indication of shorts or possibly something else). While I turned on the interrupter, I got a consistent glow in a fluorescent bulb. When I cranked up the duty just slightly (Hooray!) I got arks. However this only lasted for about 10 seconds at which the whole coil just shut off (no arks, no glowing bulb). I tried turning the interrupter on and off etc to no success. Has anyone else experienced something like this before? Also, the regulator temperature was fine.

Next test:
Considering a problem with feedback, I just added a second turn to my current transformer. Upon powering on the coil and interrupter, the bulb glowed and flickered (I think brighter than it had before) and I was able to get a few arks until the coil once again shut off abruptly after about 4-5 seconds.
« Last Edit: April 19, 2019, 08:32:35 PM by Seb555 »

Offline Fumeaux

  • High Voltage Experimenter
  • **
  • Posts: 59
  • Karma: +7/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #3 on: April 19, 2019, 08:50:36 PM »
I have looked at a few of the pages on the link you provided (http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/), and I have used javaTC for my coil, but I'm not sure what sort of values I should be looking for.

My resonant frequency is ~125.1kHz, secondary Q is 111, and reactance at resonance is 73057 (the page on secondary design recommends 50kOhms).
The frequency is not that typical for a sstc but fine. I'm not to sure myselfe what the Q means, but as far as I understood it, it should be fine. The Reactance should be fine too, but you could make a new toroid with a bigger major diameter to get the Reactance down. But 70k should also work, you just won't get the biggest sparks.

Also, it seems strongly advised to prevent any overlaps whatsoever in the secondary windings. I unfortunately have a few overlaps in my secondary.
Overlaps can kill a secondary coil, try to fix them now, or you might have to do it later. Small overlaps (two winding are switched) can be okey, aslong as there isn't too big of a voltage present. At higher power it will become more of a problem.

For the primary, I have 12 turns of 14AWG ~1.5cm away from the secondary.
Should be fine. More important is the Inductance and Reactance of the Primary. Also I strongly advise you to lose the primary cap. You want a SSTC and not a DRSSTC.

Just remember: You can add a Cap there (and it would still be a sstc), but you can't just choose any value for the cap. Its Reactance and the one of the primary coil should cancel out. This Cap is probably the reason for many of your dead igbts. So just remove it (for now). The output will be smaller, but you can compensate it with your primary (lower the reactance).

My coupling coefficient is 0.316k.
I think 0.3 to 0.45 are normal values. Higher is better for a SSTC.

In regards to testing the driver etc, I had done so before I assembled everything together. The output signal across the IGBTs from my GDT looked good, but I will test it again as I guess it might have been damaged. My multimeter has a temperature probe, so I will try testing the temperature of the voltage regulators and IGBTs.
Also, do you think it would be worthwhile to try adjusting the height of the toroid. Currently, it's about 4cm above the last secondary winding.
In addition, I may also try adding an antenna again in the case that my CT is not functioning properly.

EDIT:
I did not find that either the 12V rail or the 5V rail was shorted to ground.

Also, I just tested the coil again. The purpose of my test was to see if the 12V regulator was heating up at all (an indication of shorts or possibly something else). While I turned on the interrupter, I got a consistent glow in a fluorescent bulb. When I cranked up the duty just slightly (Hooray!) I got arks. However this only lasted for about 10 seconds at which the whole coil just shut off (no arks, no glowing bulb). I tried turning the interrupter on and off etc to no success. Has anyone else experienced something like this before? Also, the regulator temperature was fine.
You don't need to probe the temperature. Just feel whether it is warm or not.

A higher toroid doesn't help with anything. In general you should lower it, to have a better electrical field. But it is fine where it is. You can play with such thing once the coil is running.

For now get rid of both antenna and ct and use something like a 555 to generate a 130kHz signal. Older SSTC had a fixed frequency as well. When the coil runs you can try different feedback types.

Yeah you just killed your IGBTs. Bad tuning and/or bad switching make IGBTs die even when switching rather low power. But it is still a good sign that the rest kinda works.

In short:
  • No primary cap
  • Fixed PWM signal as feedback
  • Maybe put some kind of big load in series to your wall power. So if anything dies it will die with a smaller bang.

Offline Seb555

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #4 on: April 19, 2019, 09:16:51 PM »
I though the primary cap in a SSTC was for DC blocking purposes? I'm using a 1.5uF film cap which brings down the resonant frequency of the primary to around 25kHz (according to JavaTC). I may try removing it though.

In my very first tests, I tried using a 555 oscillator circuit to drive the feedback signal, but that's what caused my IGBT to fail shorted out across the collector-emitter (this was the only time I have lost an IGBT thus far), so I'm reluctant to try that again. However, I do think that the feedback is the source of the problem. When I added a second turn to the current transformer, I was able to get a few consistent runs. It's only when I turn the interrupter up to anything above a really low duty cycle that the coil shuts off. For whatever reason, I can "reset" the coil, simply by turning the power off and on again, at which point the interrupter (at a low duty cycle) starts to work again. I was able to get a few photos too!



According to this link: https://www.loneoceans.com/labs/sstc2/
The ground wire used with the CT can sometimes pick up interference from the primary etc. Possibly what's going on is that once I turn the power up sufficiently, the interference becomes so great that the feedback mechanism fails and the coil shuts off as a result.

Offline Fumeaux

  • High Voltage Experimenter
  • **
  • Posts: 59
  • Karma: +7/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #5 on: April 19, 2019, 09:51:07 PM »
I though the primary cap in a SSTC was for DC blocking purposes? I'm using a 1.5uF film cap which brings down the resonant frequency of the primary to around 25kHz (according to JavaTC). I may try removing it though.
I might have been wrong there. I just read some of loneoceans articel and it does make sence. Keep it.

In my very first tests, I tried using a 555 oscillator circuit to drive the feedback signal, but that's what caused my IGBT to fail shorted out across the collector-emitter (this was the only time I have lost an IGBT thus far), so I'm reluctant to try that again. However, I do think that the feedback is the source of the problem. When I added a second turn to the current transformer, I was able to get a few consistent runs. It's only when I turn the interrupter up to anything above a really low duty cycle that the coil shuts off. For whatever reason, I can "reset" the coil, simply by turning the power off and on again, at which point the interrupter (at a low duty cycle) starts to work again. I was able to get a few photos too!
In your schematic you have added a 470pF cap and a 100k resistor to the feedback part of your circuit. Loneocean's doesn't have this and steve's does neither. Those components put some sort of delay onto the feedback signal. Maybe they mess thing up. Can you test if removing them help?

According to this link: https://www.loneoceans.com/labs/sstc2/
The ground wire used with the CT can sometimes pick up interference from the primary etc. Possibly what's going on is that once I turn the power up sufficiently, the interference becomes so great that the feedback mechanism fails and the coil shuts off as a result.
That is quite possible.

An idea: Could it also be that as your feedback CT is physically quite large (high in inductance), that your feedback loop doesn't make that good of a "contact" with the other winding and therefore the signal you get out of it is distorted?

Online Laci

  • High Voltage Technician
  • ***
  • Posts: 199
  • Karma: +6/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #6 on: April 21, 2019, 12:09:13 PM »
If you want to make it double resonant in the future,it's recommended to use the Universal Driver version 1.3B or above.I used it with my SSTC and works fine with antenna feedback too!
https://www.stevehv.4hv.org/new_driver.html

Offline Seb555

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #7 on: April 23, 2019, 01:58:37 PM »
Wow! Thanks for the resource. I will definitely look into this.
I have a few questions about the schematic you provided though.
- I saw this same flip-flop configuration in a previous design by Steve:

 Why, like on this schematic as well, is the interruptor connected to the PRE? I thought that the whole point of the flip-flop was to allow for soft switching - ie a clock pulse from the feedback will turn off the flip-flop not the interruptor. How is this done when the interruptor is on the PRE?

- Also, why (in the schematic you provided) are there two sets of MOSFETs to drive the GDT? I understand that this allows for higher power to drive the gates of the IGBTs, but how exactly does that configuration work? I see only the low side MOSFET is connected to the driver ic output, while the high side MOSFETs are connected through a 0.1uF capacitor. How does this drive the GDT?

Thanks.

Online Laci

  • High Voltage Technician
  • ***
  • Posts: 199
  • Karma: +6/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #8 on: April 23, 2019, 03:12:19 PM »
Let's talk about the new driver.
When the interrupter turns OFF,so PRE goes HIGH,CLR will be HIGH too for the set time constant by R2 and C3.In this case the output isn't changed,but when a rising edge occours on CLK,Q will be LOW.This way soft switching is achieved,as you know.
I'm not that good at logic functions so anybody can correct me if I said wrong.

The mosfet driver IC outputs a square wave,one output in phase and the other phase shifted.As you know a N MOSFET turns ON with a HIGH signal and a P MOSFET turns ON with a LOW signal and the square wave simply passes the capacitors on the P MOSFETs gates.Now you can see that at one time turns on Q1 and Q4 and the other time turns on Q2 and Q3 creating the required alternating current for the GDT.
The MOSFETs can provide way more power than the driver ICs and also not many driver IC works at 24V which is required if 1:1 ratio GDTs are used and want 24V signal for the IGBTs.

Offline Seb555

  • High Voltage Enthusiast
  • *
  • Posts: 5
  • Karma: +0/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #9 on: April 23, 2019, 09:45:19 PM »
Ok! Thanks Laci for the quick response and explanation!
I hadn't considered the role of the resistor and capacitor to make a time delay, but now I think I understand. Here is it in my own words: (just to make sure I have this right)
- First, the interrupter signal triggers the flip-flop through the PRE and turns off the CLR through the diode D7. During this time, the Tesla coil is in operation.
- Next, when the interruptor turns off (IC1A output is HIGH) the PRE no longer is turned on but the flip-flop remains in its on state for soft switching to occur.
- Then, if the IGBTs are sinking high currents and thus the current transformer feedback circuit sends a clock pulse to the flip-flop, the output Q will be brought LOW since D is tied to ground. This occurs at a zero crossing point/signal edge.
- However, if there is no feedback signal, the flip-flop will wait for the time duration R2*C3 at which point (for safety's sake of turning off the Tesla coil on interruptor command) the interruptor will override and pull the output Q low through the CLR.

Correct me if I'm wrong, but wouldn't the fiber optic receiver also need to invert the signal, as when the output of the receiver is low, the hex inverters used in the circuit would cause the PRE to be activated and the tesla coil would be in its on state?
I guess one could just invert the signal fed through the fiber optic connection before it gets to the control board if this is not the case.

In terms of the GDT, I had completely missed the fact that there were both N and P type MOSFETs used! Thanks again for clarifying that up. However, I still have one question: what could be the purpose of the diodes D15 and 14? If anything, they seem to be facing in the wrong direction! ??? If the driver output were to be low, the diode would not conduct (right?) and even if the driver signal was high - it's powered by +9V (less than 24) - I don't think the diode would conduct then either. The only explanation I can think of (in terms of the use of diodes on the gate of a FET) is for the gates to discharge, but the diode is directed towards the 24 volt supply!

Online Laci

  • High Voltage Technician
  • ***
  • Posts: 199
  • Karma: +6/-0
    • View Profile
Re: Troubleshooting my first SSTC
« Reply #10 on: April 23, 2019, 10:43:09 PM »
When both PRE and CLR are HIGH,a rising edge on CLK will turn Q LOW.The feedback circuit doesn't care about the current on the IGBTs.It only waits for a rising edge of the feedback signal when the current is zero through the IGBTs.The role of the R2 and C3 time constant is important when overcurrent occours.In this case the driving is shut down for the set time constant,so the primary current can ring down to safe levels.

Have you seen the signal indicator D18 LED?When your interrupter is ON,then turns this LED ON indicating interrupter signal,which has it's cathode connected to the fiber optic receiver!Basically the receiver inverts your interrupter's logic.

The voltages at the P MOSFETs gate can get higher than 24V because of the stray inductances and high frequencies,which are clamped to the supply voltage by diodes D14 and D15.Greatscott recently uploaded a video in which he talks about this too: https://www.youtube.com/watch?v=2v8zBj7_sxg
« Last Edit: April 23, 2019, 10:45:20 PM by Laci »

High Voltage Forum

Re: Troubleshooting my first SSTC
« Reply #10 on: April 23, 2019, 10:43:09 PM »

 


* Recent Topics and Posts

post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
Today at 08:31:55 PM
post Re: Easy access to optimal resonance frequency but the benefit is quite small
[Dual Resonant Solid State Tesla coils]
dexter
Today at 08:31:51 PM
post Easy access to optimal resonance frequency but the benefit is quite small
[Dual Resonant Solid State Tesla coils]
VNTC
May 21, 2019, 11:35:57 PM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
Mads Barnkob
May 21, 2019, 09:59:54 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Mads Barnkob
May 21, 2019, 09:51:27 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
T3sl4co1l
May 21, 2019, 09:49:03 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 21, 2019, 09:02:10 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 08:59:57 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 21, 2019, 08:28:43 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 21, 2019, 08:22:28 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 06:21:37 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 21, 2019, 06:12:55 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
profdc9
May 21, 2019, 04:06:38 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 03:56:56 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 21, 2019, 03:46:56 PM
post Re: DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
profdc9
May 21, 2019, 02:32:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 21, 2019, 06:12:18 AM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
profdc9
May 20, 2019, 11:30:34 PM
post DRSSTC design questions + project progress
[Dual Resonant Solid State Tesla coils]
Vaclav
May 20, 2019, 06:38:54 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Teravolt
May 20, 2019, 06:33:49 PM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 20, 2019, 02:27:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
hightemp1
May 20, 2019, 02:57:46 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
T3sl4co1l
May 20, 2019, 01:06:27 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 19, 2019, 09:14:59 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 19, 2019, 06:40:41 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
flyrod
May 19, 2019, 04:04:12 PM
post Re: Offgrid 48V solar to 24V battery setup
[Electronic circuits]
Mads Barnkob
May 19, 2019, 11:24:46 AM
post Re: ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
flyrod
May 19, 2019, 03:22:54 AM
post Re: Are bleeder resistors necessary if I can easily discharge my capacitor?
[Spark gap Tesla coils]
profdc9
May 19, 2019, 03:18:52 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 18, 2019, 10:48:59 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 18, 2019, 04:19:11 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
petespaco
May 17, 2019, 10:57:17 PM
post Are bleeder resistors necessary if I can easily discharge my capacitor?
[Spark gap Tesla coils]
jpb133
May 17, 2019, 09:41:56 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Uspring
May 17, 2019, 12:41:17 PM
post ZVS Mazzilli circ with active gate driver - what causes ringing?
[Electronic circuits]
82026
May 16, 2019, 04:15:58 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Fumeaux
May 16, 2019, 02:19:39 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 16, 2019, 01:50:44 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Uspring
May 16, 2019, 12:17:01 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Fumeaux
May 16, 2019, 08:45:15 AM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 15, 2019, 11:49:59 PM
post Re: Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Hydron
May 15, 2019, 10:51:33 PM
post Identification of unknown embedded computer, help needed.
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Mads Barnkob
May 15, 2019, 09:35:41 PM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Golddustpeak
May 15, 2019, 05:07:20 PM
post Re: Mounting LCD CFL's around DRSSTC?
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 15, 2019, 12:46:33 PM
post Re: General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
Mads Barnkob
May 15, 2019, 10:08:11 AM
post Re: Is one of these good?
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
May 15, 2019, 10:04:59 AM
post General Oscilloscope Probing Techniques for (DR)SSTC h-bridge
[Beginners]
L_Mangold
May 15, 2019, 12:42:46 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
hightemp1
May 14, 2019, 11:28:43 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
badpeter
May 14, 2019, 09:58:28 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic circuits]
hightemp1
May 14, 2019, 08:35:28 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