Proton BASIC Community

Definitely not PIC related!

Any ideas what capacitor type and value might be needed to charge to 500VDC and dump into a near short circuit with a minimum current of 180 amps?

Charge rate can be several seconds, time between discharge 30 seconds minimum.

I was thinking maybe starting with motor start capacitors

How about Photoflash capacitor?

Seems almost you are making a capacitive stud welder ?
I built one with a huge capacitor bank in a large box (large old electrolytics).
I discharge with a pic triggering a 1200V 1200A SCR (Because I had one).
I can also adjust to a specific voltage I want the capacitors charged to, depending on the stud size or stainless steel sheets I want to weld together.  Making your own studs is easy, simply lathe a 1mm long pi-.pi on any stainless screw.  The initial current disintegrate the pi-pi which is basically just a spacer, and then flash the stud to the object.
If charged the pic also discharge the capacitor bank so you don't get nasty surprises.
Sorry if this is not what you have in mind, but that's how it looks from here...

Photo flashlight capacitors are made to do this huge current dumping.
By paralleling a few of them you can increase the current dump rate to suit your purpose.

Hi See-mos you need to use a Pulse Grade Capacitor


https://hkfc-industrial.com/product/pulse-grade-capacitors_energy-discharge-capacitors_stp-02/

regards
Craig

Thanks for the information, very useful.

One source that I asked said I needed to store 90kW.  he had obviously done the maths 

@Fanie, no, not a stud welder but I will reveal all later.  BTW I did a lot with stud and spot welders when I was repairing welding equipment for a living.

Be a good Rat killer!

Quote from: JonW on Dec 08, 2024, 05:29 PMBe a good Rat killer!

That's a 10$ per zap.   

Quote from: See_Mos on Dec 05, 2024, 06:10 PMDefinitely not PIC related!

Any ideas what capacitor type and value might be needed to charge to 500VDC and dump into a near short circuit with a minimum current of 180 amps?

Charge rate can be several seconds, time between discharge 30 seconds minimum.

I was thinking maybe starting with motor start capacitors

I'm sorry I missed this post. It sounds like it could be a lot of fun. To some extent the number of joules per pulse, the device life expectancy and the desired pulse shape will determine the cost of the capacitors involved. I remember when one of my capacitor discharge driven coil experiments launched a copper ring vertically up to the roof of a warehouse narrowly missing a large mercury vapor lamp.The ring ricocheted off the roof and impacted a new analog meter sitting on another work bench. Quite a expensive exercise. Lots of energy can be released in a short period of time...a bit like an explosion really.
kk

Quote from: ken_k on Dec 12, 2024, 12:55 AMQuite a expensive exercise. Lots of energy can be released in a short period of time...a bit like an explosion really.

This is actually how a sub-type of electric blasting caps (detonators) work - large current is dropped on a resistance wire with pico-seconds rising time which wire is turned immediately into plasma. The heat from the plasma expands really fast which creates enough pressure to detonate a high explosive. Because you can time those detonators within pico-seconds, they are used in the high-explosive lenses in nuclear explosions. 

Little off topic   

Quote from: trastikata on Dec 12, 2024, 05:11 PMThis is actually how a sub-type of electric blasting caps (detonators) work

Not quite but very close.  could be good for killing moles though