Coleman 5.4V Flashcell Cordless Screwdriver,
Interesting information obtained from my last link, you get two 360F capacitors with this screwdriver, from $35 including shipping (maybe cheaper elsewhere)
http://www.amazon.com/Coleman-5-4V-Flashcell-Cordless-Screwdriver/dp/B001U8FF5Q
Compare the information PDF link to the picture, it looks the same to me.
http://fullpowerinc.com/PDF%20Documents/Ness360.pdf
cat

Maybe there's something serious wrong with my JT because the AAA battery is fading fast now at 0.911 volts, and the UC is only 1.316 volts. The UC started at 1.130 volts.

Paul

powercat:

Great info!  Those look to be wired in series...I suppose they need the higher voltage to run the driver motor.

Bill

Quote from: PaulLowrance on December 10, 2009, 07:54:54 PM
Maybe there's something serious wrong with my JT because the AAA battery is fading fast now at 0.911 volts, and the UC is only 1.316 volts. The UC started at 1.130 volts.

Paul

eitehr that or you gat a battery that is half life . Need you input current this tells most all . Also are you running a secondary . One of the side effects of my secondary is the current consumption goes down . the oppisite of what you would expect and i also run leds on the secondary . Something is wrong because mine has been running for weeks and still 1.3 volts on the run battery . bcap is now 1.905 .Also i made three of them and they are all the same so i know its replica table . I suspect a bum battery or the current was set to high or the capacitor was not right . when i put my capacitor i=on it brightens up a bit so it changes the frequency slightly . The is a stupid question and i did know it . how are you measuring the frequency without a frequency meter  ?

Truthfinder:

QuoteIm afraid i disagree with you about the batteries in parallel, ive done that many a time and there's no issue providing that voltages are the same and the 'ah' are the same. If the 'ah' is too radical in difference then they will normally 'equalize' to the lowest 'ah' rating in the pack and your overall current will be that of the lowest rated 'ah' x 2.

Your comments about the ampere-hours don't make sense.  It doesn't work like that for ampere-hours.  However, you acknowledge the issue of one battery discharging into the other battery, as does Paul.  This is not a healthy situation.  It can also happen towards the end of the life of the two batteries.  The one that starts to die first and becomes the load for the healthier battery.  So at the beginning and at the end, you loose energy and potentially damage the batteries.

Chances are noting is going to happen in most cases with small batteries.  However you never know, a small alkaline battery can source quite a bit of current.  It is simply bad practice and should not be done.

I had a glance at a Magnacoaster instruction manual once.  That fool Richard shows a diagram with big car lead-acid batteries wired in parallel.  That is insane and very dangerous.  If you submitted a product like that to UL for approval they would refuse you and behind your back laugh in your face.

For higher-voltage batteries you can give them a common ground and then use diodes to bridge all of the positive outputs together.  Then you can get your big current and avoid thermonuclear meltdown at the relatively small price of a diode voltage drop.

Albert:

QuoteDIITO . . total nonsense . you can put any battery in parallel to get more current if there the same volts

I hope that you studied my mini treatise on battery voltages for you.

Paul:

QuoteAnd if someone's afraid of too much current, then discharge the batteries and parallel them.

Love your swagger.  I find it very ironic that you say "discharge the batteries."

QuoteMy UC is ~ 550 farads at low voltages (less than 0.4V), and lets just assume it's 650F at 2.7V,

Are you acknowledging that the UC capacitance is a function of voltage, which is what I have been saying the whole time?

QuoteAs far as I'm concerned, one can prove a JT is cop>1 without doubt by ... by using one 2000mAh to 2500mAh NiMH battery to charge a BCAP0650 4 times.

This is where you loose it.  Forgetting about the JT, all you can say when you run a test like that is you were able to make a measurement of how much energy could be extracted out of the battery under these conditions with a certain error margin.  You can't make any sort of statement about COP.  Plus a certain type of battery will have a certain average energy content with some sort of standard deviation, and if you want to get picky the mean and standard deviation would be set on a batch by batch basis.

Albert:

QuoteIt is here where the magic really begins and the REAL magic is that an ultracap can convert that into real energy .

Let me briefly describe what's going on when a JT generates a spike.  The transistor switches on and current flows through the coil in the JT "transformer."  When the transistor switches off the energy in the coil (1/2 L i-squared) will become a voltage+current spike that goes through the diode and then into the cap.  It can be a cap or an ultracap, either one will absorb the energy in the spike.  That's it, there is no magic.

I can suggest a little experiment.  Take a standard JT circuit and connect your scope to the LED to see the pulses on your scope when the LED fires.  Then replace the LED with a 50-ohm resistor, and look at the scope.  Do the same for 500 and 5K ohm resistors.  You will see that the larger the resistor value, the higher the voltage in the spike, and the shorter the time of the spike.  This is showing you how a discharging inductor reacts to different loads.

Then change the 5K resistor for a regular 25-volt 20,000 uF electrolytic cap and look at the scope.  The voltage spikes are now gone - completely gone.  However, each time the JT fires the voltage on the cap increases, like a step.  You will also notice that the rate of the voltage increase starts to slow down the higher the voltage on the capacitor.  Do you know why this is happening?

MileHigh