Pyle Power Capacitor, Pyle of what?

[brucegseidner]

How is it possible to produce a 5 Farad capacitor for $50, let alone one that weighs in at 5lbs and has a blue led display for the "power" available to the amplifier at any given time. What is this?

Amazon.com: PYLE PLCAPE50 5.0 Farad Digital Power Capacitor: Electronics

[SGregory]

$10 of it is the cost of the Blue LED. $1 for the case and $39 is sucker cash.

[brucegseidner]

You have articulated my gut reaction. But my question remains. What is this thing?

[tubelab.com]

What is this thing?

It is a "stiffening capacitor". It is used in auto sound applications where the pulses of current drawn by a 1.21 jiggowatt subwoofer cause problems with the cars electrical system. The capacitor goes across the 12 volt supply right at the amplifier and provides energy storage to supply the amplifier when the bass note goes THUMP! Based on the size I think the 5 Farad rating may be a bit optimistic.

Due to the large number of thumpa thumpa cars in the south Florida area, even Walmart sells these things. The one I got at Walmart is 2 Farads, just the cap, no case, no LEDs. It looks just like a big fat electrolytic cap except the usual blue shrink wrap is silver. Why did I buy one? It fixes the havoc that a 100watt ham radio in SSB mode caused on the electronics in a Toyota pickup truck.

[metalsculptor]

Digital in the name worries me, it could be something strange like a 5000uF 450V capacitor and some form of up / down converter, not much use if that is the case as the ESR would be high. The stupid thing is that best place for capacitance in on the amplifier supply rails not the feed to the amplifier PSU.

FWIW it is an Amazon special price with the normal price nearer $75 and capacitors have shrunk quite drastically in the past 10 years.

[thebulbguy]

The electronic goldmine has a bunch of ultracaps on sale now if you feel like messing around with them - 30 bucks will get you a 3000F (yeah, 3 thousand farads) 2.7V cap that is very good at vaporizing wire and such. They sell smaller (2600F I think) ones as well for even cheaper. I bought a few of the bigger ones figuring someday I'll come up with a cool use for them.

[brucegseidner]

Ok, so these are essentially being used as batteries for an automobile amplifier, but can these be used as filter capacitors in a conventional home audio power supply?

[Zero Cool]

there are reasons why you wouldn't want to use caps like this in a home supply. 1- the voltage rating is low. these are designed for 12-15v. 2- the start up current is MASSIVE! you have to charge these things up with a light bulb before connecting them or the arc like a mother! 3- massive strain on a bridge rectifier 5- slow discharge when compared to a bank of smaller caps = the the same uf etc etc etc.

Like tubelab said. these stiffening caps help with those kids and there jiggawatt stereos. its amazing just how much current those boom box amps really draw. I am adding a small but high quality amp set up to my car with a 375w amp for the subs and at full power it draws almost 50 amps! (it will never see full power in my car but...) add to that a 4x75w amp for the 4 corners that draws about the same current and that is a max of 100amps! and thats SMALL stuff. these days kids have amps that are in the KW range!

so you could potentially have 75-100amp peaks hanging off the end of 15-20' of 8ga maybe 4ga wire if you can afford it. the voltage sag is huge. these big fat caps help hold up that end of the line for those short duration peaks.

I have been curious if they really are what they say they are. I picked up a pair of 1F caps at a swap meet for $10 and they do run a .5amp light bulb for a considerable amount of time. I need to figure out the RC time constant and see if i can calc what the real capacitance is.

[alexberg]

Cornell Dubilier makes somewhat similar.
In regard to the application - just read the datasheet.
Do not use flash type caps - they are not designed to withstand
voltage applied for prolonged period of time.
Well, what flash operates from 12 VDC?! LED... based...
Price seems to be too low: decent 3"x6" power lytic costs
at least 50% more.
Please pay attention to the manufaturing date - they may dry out.

[tubelab.com]

Ok, so these are essentially being used as batteries for an automobile amplifier, but can these be used as filter capacitors in a conventional home audio power supply?

The big cap I got from Walmart says 2F 16V right on it. So you might be able to use it in a 12 volt power supply if the surge and start currents are dealt with.

Do not use flash type caps - they are not designed to withstand
voltage applied for prolonged period of time......Well, what flash operates from 12 VDC?! LED... based...

I don't know where that quote came from but I did use a pair of 375 volt photoflash caps in series in a tube amp about 10 years ago. They worked fine for about 6 years and then one of them just decided to spew its guts all over the inside of the amp. Each cap saw only 200 volts and there were equalizing resistors across the caps.

Most camera phones use a multi chip LED for the flash. Peak current is in the 1/2 amp range. That is usually provided by the phones battery and a ceramic or tantalum cap in the 50uF range.