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how to charge kapacitator Answered

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I don't know how (actually I don't know what to use) to charge capacitator .Someone help me? I know i need at least 5kV power supply but where to find it?

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Emeyo (author)2012-03-20

Can any one tell me how to make a boost converter 18v to 400v with transistors, without an IC . maximum 2 transistors !!

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Big Bwana (author)2008-06-22

When you are charging them make sure you put a discharge resistor across them for your own safety BEFORE you charge them... Other wise you can charge them like any other small cap, just apply dc to them, and the inrush into a large cap like those ones in the picture will present a problem to most off line chargers or power supplies so you might want to limit the inrush by using a resistor or a variable inrush protector like those found in a computer power supply, only larger..... Or if your charging them straight off the mains you will need a time delay breaker or fuse, and don't be surprised if you trip most household breakers while charging them...

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lemonie (author)2007-07-14

Nice use of the letter 'K' (unless you don't know how to spell).

HamO has alreay pointed out thet you don't need 5KV, but where did you get that idea from?
I think I can also make out 400VDC on that one, so anything up to 400V Dc would do (including the 9V battery shown)
What do you plan to do with these anyway?

L

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Dantex (author)lemonie2007-07-14

-i am not from USA or England, i am from Croatia and i learn English 3 years -i thought that you need at least 400V DC to charge it to full capacity (i think to charge 330V capacitator you need 330V-to full charge capacitator you need 330V power source) -to blow stuff up

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lemonie (author)Dantex2007-07-14

Right, so you want to blow stuff up - cool! Perhaps you could fing a big diode an charge these off the mains supply? L

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static (author)lemonie2007-10-08

A bridge rectifier works best for charging a capacitor from the mains. Just don't forget your components will see voltages higher than the nominal 120/240 V., select your components accordingly. Google rms and rms calculators to learn more. Over voltage thos capacitors dantex you will see explosions or missiles that can punch perfectly round holes in thermoset plastic cabinets. Perhaps I should be telling datex that ? ;)

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Big Bwana (author)static2008-06-22

Or you could hook them upto direct AC, I've never seen the know it all electrician at work run so fast, it was louder then a 12 gauge when he flipped that breaker, and you said they go threw the box, I couldn't find the box (( I did find the heat sink )) I guess they don't like 575 VAC hooked upto the 800 VDC output...

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HamO (author)2007-07-14

Also I think it should be mentioned that these capacitors, when fully charged, will present an extreme hazard if not handled properly. 3900uF at 400V '''''WILL''' shock the snot right out of you. Please be careful!

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Big Bwana (author)HamO2008-06-22

39,000 uF at 400 VDC ,those are from a motor speed controller and I'm guessing about a 5 HP motor speed controller, they will not shock the snot out of you, they WILL KILL YOU.....

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Goodhart (author)2007-10-08

Paraphrased from a discussion on Magnetic Diodes: There are two significant aspects in the measurement of capacitors. The first is the voltage it can be charged with before the dielectric breaks down (and all the bad stuff that can emulate from that condition), and the other is the total charge it can amass. The voltage is a function of the insulating assets of the substance(s) between the plates, and the distance between the plates. The farther away the plates are, the higher the voltage can obtain to be before the insulator is contravened. The charge is a function of the area of the plates, and the distance between them. The bigger the plates, and the nearer the plates are, the more charge you can store. A third factor is the internal resistance of the capacitor. The lower the resistance, the faster the charge can be delivered to the load, and thus the higher the current. The energy delivered to the load is the product of the voltage and the current. If the voltage is as high as the insulator can withstand, and the charge is delivered to the load with the least resistance possible, then the amount of energy delivered to the load will be maximized. If you have two plates close together, and charged with opposite charges, they will attract one another. If you do work against this attraction by pulling the plates apart, you are adding energy to the capacitor. You can get this energy back when you dump it into the load. One way to measure the energy stored in a capacitor is to dump the energy into a load, and measure the output. The load can be a heating coil in a water bath, and you can use a thermometer to measure the change in temperature of the water.

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HamO (author)2007-07-14

Why would you need a 5KV power supply to charge, from what I can tell are, 400V capacitors?

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