What should I build with six ultracapacitors?

I bought six 2600F 2.5V ultracapacitors from Electronic Goldmine. They were on sale a couple weeks ago, and this was one of my rare impulse purchases. I am thinking of building a portable capacitive discharge welder, or perhaps conventional spot welder. What are your ideas?

Category:

Science & Technology

Tags:

• ultracapacitor
• spot welder
• capacitive discharge welder

[peshozmiata]

Can you propel an electric bike with these? They seem to have crazy-high energy density for capacitors.

[bkraz333]

@peshozmiata They have a very high power density, meaning that you can pull lots of amps for their mass, but the energy density is actually very low compared to almost any battery technology. Electric vehicles can make use of both capacitors and batteries so that high amperage is available for acceleration, and high energy capacity is available for vehicle range. The capacitors can be charged from regenerative braking or batteries.

[SuperDisco91]

That's some pretty low voltage for a coil gun. I think if you powered a coil gun with those, it would just melt your coil.

[bkraz333]

@SuperDisco91 Yup. The problem is the coil's inductance will not allow much current to flow with such a low voltage. A relatively high voltage is needed to overcome the coil's inductance and force lots of current through the coil. Check out my videos regarding transcranial magnetic stimulation to see a high voltage discharge setup with 15uH coil.

[4lifeNerdfighter]

doesn't it decrease the overall capacitance to put them in series? shouldn't they be parallel?

[bkraz333]

@4lifeNerdfighter You are right; adding capacitors in series does decrease the total amount of capacitance, but it allows higher voltages to be stored in the group of capacitors. Higher voltages compensate for the loss of capacitance. In fact, the total amount of energy stored is the same for a parallel or series arrangement of the same group of caps. So why series? It allows me to store a higher voltage, and higher voltages will cause higher currents to flow for a given load resistance.

[Terrormink]

@morto360 Flux capacitors already exist and are used in many electronics. However, they do not permit time travel, nor are they actually called "flux capacitors". They are called inductors.

[thedudeman9000]

Sorry if this is has been suggested before, but I would love to see if that bank would start a car with no battery. I would more than love to see that, actually. I know, I can work it out mathematically but seeing it work seems better right now. : ) Guessing by the spot weld you did, it should work for sure. (I've welded with a bank of golfcart batteries, and even done a practical spot weld with two car batteries.)

[thedudeman9000]

@Dracanse No, even in the current 15V configuration it wouldn't. In my experience with car audio I've seen capacitors up to 18V used. Up to like 4 Farad. I've also overvolted some car audio amps to about 21V before due to adding massive amounts of capacitors to a homemade power supply and not even checking the peak charge voltage. (hehe i was like 12) These would be absolutely wonderful in a car audio install.

[TheElectricnoob]

You forgot one other important aspect with the big SCR, it also needs a clamp to provide about 500 kilos of pressure on the terminals, this due to the way these are made internally.

[paoki001]

Why can use it as nitro (N2O) in electric bikes .. Instant accelaration

[bombersander]

put a car claxon on your bicycle

[SirDeanosity]

IGBTs (Insulated Gate Bipolar Transistors) come in this size and would work well for a spot weld with the possible exception of a higher voltage drop than an SCR.

[Dracanse]

i have been looking at these and i want to use them for car audio.. but would it fry my system?

[yo6ial]

Portable railgun. :D

[Aerospacesmith]

Quarter Shrinker!!!

Checkout Tesla Mania

[TheLophius]

EMP (electromagnetic pulse) gun