a capacitor b4 supplying power to the pelt?

I'm planning to wire up a 2200uF E-cap to my 5V rail JUST b4 it goes into the peltier.... does it help my peltier in achieving better coolign results? Can it be done? I have bought the cap n dun wanna waste it

i dont see why it would be necessary or why it would help... never heard of anyone wanting to use a capacitor with their pelt wiring.

No, it won't be of any use. If the TEC drew spikes of current there might be some value, but TEC's draw DC current.

I don't think you'll notice a difference, although there is a spike when you power up the TEC, it still needs some time to cool the CPU/Coldplate.

You'll see many people racing with RC cars that use a CAP to give it a bit more 'punch' (Acceleration), but as I said a TEC doesn't get cold immediately, while a RC motor does use the power immediately.

@ Since87 It doesn't matter if it's DC or AC current, the application however does matter.

KILLorBE said:

@ Since87 It doesn't matter if it's DC or AC current, the application however does matter.

Click to expand...

KILLorBE,

I'm a 40 year old electrical engineer. I know very well when a cap does or does not matter.

The fact that for all practical purposes a TEC draws a DC current is precisely the reason the cap will have no value. An ideal capacitor has absolutely no significance in a truly DC circuit. It is effectively 'not there'. (Any non-idealities of an actual capacitor are irrelevant at best.)

The fact that the voltage to the TEC will come up a bit more slowly at power up with the cap in place is of no value, and is ultimately irrelevant to the cooling of the TEC.

The reason a cap gives an RC car more punch, is because that is not a DC situation. (The voltage and current of the motor are changing.)

Since87 said:

KILLorBE,

I'm a 40 year old electrical engineer. I know very well when a cap does or does not matter.

The fact that for all practical purposes a TEC draws a DC current is precisely the reason the cap will have no value. An ideal capacitor has absolutely no significance in a truly DC circuit. It is effectively 'not there'. (Any non-idealities of an actual capacitor are irrelevant at best.)

The fact that the voltage to the TEC will come up a bit more slowly at power up with the cap in place is of no value, and is ultimately irrelevant to the cooling of the TEC.

The reason a cap gives an RC car more punch, is because that is not a DC situation. (The voltage and current of the motor are changing.)

Click to expand...

I'm not gonna argue with you, but you should give some sort of explanation when you post (I'm not saying that you should, but OC.com could sure use some members like you). I'm sure you know what I meant.....I sure know what you meant.

cool guys...

i was thinking of using it to clear the spikes in my al cheapo PSU... i got a 2200uF 16V capacitor....

I doubt that filtering power supply noise is going to make any meaningful difference, but it won't hurt to install the cap as long as it has a high enough voltage rating.

It would be better to put the cap at the power supply end of the cabling so that any spikes the supply puts out travel a short distance and then pass through the cap back to the supply.

However, depending on what TEC you are using, the ESR (equivalent series resistance) of that big electrolytic cap may well be higher than the resistance of the TEC, in which case the majority of the spike may pass through the TEC anyway.

So, then you have to throw in the issue of lead inductance, and you can get into a big hairy analysis of the situation, when it really just doesn't matter in the end.

There may be some benefit to a capacitor near the supply in terms of EMI reduction, but something like a 0.1 uf ceramic or film capacitor would be of more benefit in that regard.