My coin shrinker uses a simple mechanical spark gap switch for exactly the reasons that you mentioned about triggered spark gaps. They are tricky to adjust and can fire unpredictably. I typically use about 7200 Joules to shrink a coin and you don't want that switch to fire unpredictably! My mechanical spark gap switch is very precise. I can bring the contacts to within 0.5 mm of each other and can trigger down to about 2000 volts which is as low as I ever need.
@gristc4 жыл бұрын
Yeah, the coil shrinkers I've seen on here use mechanical switching too. Don't suppose you have a vid or write up about yours?
@stevewhite62524 жыл бұрын
@@gristc Have a look at "highvoltageforum.net". This is a forum concerned with high voltage. Look in the "Capacitor Bank" section and you will find extensive pictures of my pulsed power generator. My user name on there is "MRMILSTAR".
@dalenassar9152 Жыл бұрын
You could make the power supply SO much safer and simpliler by using one NST (neon sign transformer), rather than the ultra-leathal MOTs !
@gristc7 ай бұрын
Yeah, you use what you have. I now have NSTs and they are much nicer to deal with :)
@gbhxn444Ай бұрын
hi sir ,i want to ask, how much ohm and watt, a single resistor that you connect multiple in parallel and series that you used as negative wire on the transformer that connect with the diode? sir.
@sanghyeonpark72266 жыл бұрын
Awesome video! I like your setup
@Biokemist-o3k Жыл бұрын
I know this was 3 years ago but could I run this spark gap at 60 or 120 hertz?
@gristc Жыл бұрын
I guess you could, but if that's what you want to do you'd be better off with a rotary spark gap. The neat thing about this one is the ability to just trigger a single arc on demand
@homevalueglass38094 жыл бұрын
Very cool, I would have never thought of using a 3rd electrode to trigger the spark, very ingenious. I am ordering supplies to try and build a pulsed spark gap and am going to try 300v spark gas tube that's used for circuit protection then adjust how fast the capacitor fills with a motor speed controller, to control spark speed. If that doesnt work out, I bought electrodes like you have and a photo flash transformer that'll get up to 12kv. I do have one big question I've been trying to figure out. What happens to the voltage post-spark? Does the voltage remain the same as the circuit continues or does it change entirely? The reason I need to know this is because I am thinking about also building a low pass filter for post-spark, to keep the device from broadcasting on radio channels? Though if the end voltage is too great, will be hard to cheaply build the filter because they dont really make 500w potentiometers.
@Biokemist-o3k7 ай бұрын
I am still working on the same device and I wanted to ask you about your switching the 2000 volts and what problems you had with the gap width. I like your idea of the rotary spark gap however I was watching Les's Lab and he was using a triggered spark gap at 100 hertz and lower to run a laser. How would I set up a rotary gap to perform at 60 cycles per second or 120. It seems that would be really fast or am I missing something?
@gristc7 ай бұрын
The main problem was just getting the adjustment correct, so it would trigger when I wanted and not when I didn't. I'm having a play with a rotary gap at the moment. To get one that syncs with your mains you want to get an "induction" motor. They are wound so that the motor will always be in sync with the sine wave that's powering them. I am finding that mine (motor speed 50Hz so switching at 100Hz) seems too fast for this and am having a go at gearing it down to 20Hz. They're great for Tesla Coils though, as you want the higher frequencies then. Hoping to get some more time with my gap this weekend and make a vid about it.
@Biokemist-o3k7 ай бұрын
@@gristc Fantastic Thank you! I found Les's Lab's triggered spark gap that he made but I have to get my lathe up and running and then figure out how to make what he made. For someone who knows what they are doing it seems pretty easy but I do n ot..lol
@bobbowie53346 жыл бұрын
Have you tried to start a _HPS_ lamp with that setup?
@dalenassar91525 жыл бұрын
This reply is worth ten times the video!!! I can't understand why there are no replies. I would like to ask you: 1) when the pulse transformer is connected as you suggest, to eliminate the third electrode, do you also eliminate the voltage diver and pulse caps? 2) can one of those 5W laser diode lasers fire the gap by shining it between the electrodes? I would guess that the shorter wavelengths (near UV like 450nm) would be best?
@tomtechtod92006 жыл бұрын
good video, thanks. those caps look frightening for low voltage guys like me, LOL
@sadafijaz75028 жыл бұрын
i want to make trigger circuit for spark gap.how i should make.
@gristc8 жыл бұрын
Not sure what you're asking. I go through the components in the video.
@sadafijaz75028 жыл бұрын
Actually i want to produce x-ray by spark.SO i want to apply high voltage to spark gap.
@johnwald17147 ай бұрын
Okay don't lie. We all know you're experimenting with time travel with that flux capacitor :-)
@beforebefore8 жыл бұрын
It's not so much "because an arc has much less resistance than air"... it's because you ionize the air around the low power HV spark, which lowers the gap resistance for the high power spark... nice job anyway! I believe the electrodes should be more pointed... so that the low power spark ionization can be more useful... as it is, the possible arc initialization area for the high power spark gap has a lot of surface area... possibly making it unreliable. Are you using tungsten spark gap electrodes? Unless you are planning on MUCH larger capacitors, small TIG welding lanthanated tungsten electrodes are cheap, plentiful, and last a long time. (don't use thoriated tungsten... they will pre-ionize the air in the gap!) I'm rather confused why you don't have the low power (25kV) spark generator Ground ("low side left floating") connected with the high power (4kV) "-" connection? You are losing most of the effectiveness of that 25kV spark generator coil. Without that "return path", you run the risk of causing internal insulation breakdown inside the black HV pulse transformer. If that transformer ground were connected, you could move the "trigger electrode" MUCH further away from your lower voltage, but high power electrodes. BETTER YET... you could use a HV decoupling inductor (high permeability toroid core with a few turns of HV rated wire) in series with the 4KV "+" connection, then connect the HV (25kV) trigger pulse directly to the "+" spark gap electrode, eliminating the lower (3rd) "trigger" electrode. Best to add a 5kV "spark gap cap" across the 4kV capacitor bank to protect it (or other fixed/reliable spark gap device). Really, if the inductor is adequately designed, it will do a great job of isolating that 25kV pulse from the 4kV caps... but I still like to put a full 25kV rated capacitor across the LV (4kV for you) cap bank. HV "trigger" transformer "-" lead still must connect with the 4kV cap bank "-" at the "-" spark gap electrode. The inductor keeps the trigger pulse from going back into the 4kV cap bank, but allows it to jump the spark gap... ionizing the air gap, allowing the LV (4kV) to begin conducting with the BIG SPARK. This is how DC arc lamp ballasts ignite the arc lamp... low voltage high current DC supply to maintain the arc (plasma), high-voltage low power ignition spark to get things going. SCR = Silicon Controlled Rectifier... not Relay ;-) Ever considered making a LTSG? :-) (Laser Triggered Spark Gap... not an easy DIY trick though)
@dalenassar91525 жыл бұрын
This reply is worth ten times the video!!! I can't understand why there are no replies. I would like to ask you: 1) when the pulse transformer is connected as you suggest, to eliminate the third electrode, do you also eliminate the voltage diver and pulse caps? 2) can one of those 5W laser diode lasers fire the gap by shining it between the electrodes? I would guess that the shorter wavelengths (near UV like 450nm) would be best?
@Alexelectricalengineering8 жыл бұрын
It's not silicon controlled relay, it's silicon controlled rectifier, thumbs up :)
@gristc8 жыл бұрын
Oops, right you are. My stupid brain always mixes that one up.
@Alexelectricalengineering8 жыл бұрын
gristc I forgot to ask are the electrodes from the spark gap made from tungsten ?
@gristc8 жыл бұрын
I believe so. Will find out and confirm once the owner is back from his current adventures.
@Alexelectricalengineering8 жыл бұрын
gristc Ok :)
@gristc8 жыл бұрын
Confirmed, they are tungsten. I'm not surprised. I've managed to weld pieces of copper together with it several times. :)