Is this actually an ultracapacitor?

(Aswer to: nntp://sci.electronics.components )

Is this actually an ultracapacitor? - it must be an accumulator?:

American Institute of Physics (AIP) (2012, July 19). New ultracapacitor delivers a jolt of energy at a constant voltage. ScienceDaily:

formatting link
Quote: "... The novel constant-voltage design, which may one day help ultracapacitors find new uses in low-voltage electric vehicle circuits and handheld electronics, is described in the American Institute of Physics' Journal of Renewable and Sustainable Energy. ... So Bakhoum has designed an ultracapacitor that maintains a near-constant voltage without a DC-DC converter. ..."

Because:

C=dQ/dV

Or?

br,

Glenn

Reply to
Glenn
Loading thread data ...

Energy stored is E = 0.5 C*V^2 so 2E/C = V^2

As the energy is 'used up' then C is reduced mechanically to maintain V constant. I guess the system monitors V and moves the plates as necessary.

Cheers

--
Syd
Reply to
Syd Rumpo

Looks pretty good at first glance, but I didn't linger long as I have to go to work soon.

Reply to
MrTallyman

Might be interesting to charge at low voltage (available) and discharge at a higher voltage (usable)........

Claims to have compensated at a 35W / 6A dischage rate, mechanically.

RL

Reply to
legg

Reminds me a bit of a (fictional) invention in Smith's "Venus Equilateral" stories. A semi-mad scientist had a need for really high voltages. He developed an insulating liquid with a ferociously high dielectric constant. He used it to fill the spaces between the plates in a capacitor, charged up the cap to a thousand volts or so... and then drained the liquid. Zowie!

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
 Click to see the full signature
Reply to
Dave Platt

Might be interesting to charge at low voltage (available) and discharge at a higher voltage (usable)........

Claims to have compensated at a 35W / 6A dischage rate, mechanically.

RL

Reply to
legg

Which requires energy input to move the plates, else conservation of energy, and/or conservation of charge is violated.

Here we go again... ;-)

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
 Click to see the full signature
Reply to
Fred Abse

formatting link

So Bakhoum has designed an ultracapacitor that maintains a near- constant voltage without a DC-DC converter. The ultracapacitor is fitted with an electromechanical system that can slowly lift the core of the device out of the electrolyte solution as the stored charged is released. As the electrolyte drains away, the device can hold less charge, thus lowering, its capacitance. Since the voltage of the capacitor is related to the ratio of the stored charge to the capacitance, the system maintains a steady voltage as charge is siphoned off.

Bakhoum built and tested a prototype of the new ultracapacitor. After attaching a 35-watt load to the device, he found he could successfully program the voltage to stay within a 4.9 to 4.6 volt range. Testing also showed that the constant-voltage mechanism operates with a 99 percent efficiency or higher. The lifetime of the electromechanical motor is expected to be about the same as the lifetime of the ultracapacitor's core, Bakhoum writes.

Reply to
Greegor

formatting link

So Bakhoum has designed an ultracapacitor that maintains a near- constant voltage without a DC-DC converter. The ultracapacitor is fitted with an electromechanical system that can slowly lift the core of the device out of the electrolyte solution as the stored charged is released. As the electrolyte drains away, the device can hold less charge, thus lowering, its capacitance. Since the voltage of the capacitor is related to the ratio of the stored charge to the capacitance, the system maintains a steady voltage as charge is siphoned off.

Bakhoum built and tested a prototype of the new ultracapacitor. After attaching a 35-watt load to the device, he found he could successfully program the voltage to stay within a 4.9 to 4.6 volt range. Testing also showed that the constant-voltage mechanism operates with a 99 percent efficiency or higher. The lifetime of the electromechanical motor is expected to be about the same as the lifetime of the ultracapacitor's core, Bakhoum writes.

Reply to
Greegor

... Also, I'm reminded of playing with my Eico 377 signal generator (classic Wien bridge, dual air variable cap). On the lowest frequency band, it's kind of unstable (it's working with ~10M resistors!), and has a long time constant, so it's easy to make it 'bounce'. Set it for a low frequency and wait for it to stabilize, then yank the dial up to a high frequency.. the waveform overshoots, rebounds and stabilizes. Or dial it up slowly, and the amplitude tracks higher than normal until you stop.

If drive power is supplied by the stored electricity, then it's just a capacitive transformer -- nothing wrong with that, and saves the difficulty of a wide range electrical converter.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
 Click to see the full signature
Reply to
Tim Williams

The Venus Equilateral stories (well, most of them) were written between 1942 and 1945. I think the "ultra-high-dielectric-constant liquid" made its appearance in the story "Firing Line" (1944) but it might have occurred earlier than that... it's been a few years since I last read through the stories.

The stories are collected in "The Complete Venus Equilateral", and are well worth reading... they portray a bunch of RF/EE types, managing a "communications relay satellite station" full of high-power vacuum tube transmitters (this was pre-transistor stuff... "Now we're cooking with glass!"), orbiting the sun at Venus's L4 point. Fun stuff, with a good dash of humor.

I don't think it's in print at the moment, but used copies are available.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
 Click to see the full signature
Reply to
Dave Platt

When was this?

RL

Reply to
legg

Which begs the question: would the liquid drain. Think electrostatic attraction.

My guess is that it would need to be pumped. Inputting energy again.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
 Click to see the full signature
Reply to
Fred Abse

Ha ha I remember that from my childhood (reprint I guess - not the 1940's!).

One story they made a matter transmitter from a scaled-up tunnel diode IIRC.

--

John Devereux
Reply to
John Devereux

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.