Imhotep's Lab Interactive FAQ

Wow that was an interesting experiment.

When I first started the test I got a rapid increase in volts, it then leveled off and started to drop slowly. After 1 hour I tweaked the pot for the sweet spot and the voltage began to rise slowly.

I am using my Bedini fan with an ignition coil in parallel; once it starts to resonate I remove the fan blades and magnets and leave it resonating.

My input current to the device is 0.54 amps the reading between the device and the charging battery is 0.09 amps so I thought I was a long way from a COP of 1 but this test shows that I am closer than I thought.

My fan will not rotate in this setup. I get a lot of heat in the fan coils and a slight increase in the ignition coil. There is some magnetic energy coming from both coils which I may be able to collect in some way and feed back to the circuit.

The primary use of my motor design will be to give me an alternative power supply for the house, getting off the grid would be better. Normal generators have some efficiency problems as you point out so Im looking at some alternative ideas for that.

Machine shops aren’t a problem, balancing is, but im sure ill be able to make something with a strobe when the time comes for that.

Again thanks for some great input

Mick

I have had very limited success in charging non rechargeable batteries.

The coils on my small fan are around 62 ohms but on my big one are around 10

I use a wire wound pot for the trigger resistor, 1k is the recommended resistance although 500 ohms and it works well.

Efficiency is a hard one because are you including the mechanical, magnetic and heat output. I usually just count volts x amps x time on both input and output plus what I can draw out of the charged battery to make my comparisons. I ignore the others but to increase the efficiency I will have to recover some of those losses.

The capacitor will charge very close to the peek of the spike voltage given time so you can say that the maximum voltage you can charge a cap to, is the peek voltage of your spikes

Mick

Good stuff. The test will depend alot on the condition of the batteries used. With two new batteries on my acrylic wheel monopole with dual coils I get a slow voltage drop (say 24.50 down to 24.40) until the wheel reaches its top speed/resonance. From here it jumps back to its starting voltage and slowly climbs. I have had it climb slowly but steadily for over 9 hours @ c25 rates, finishing up @ 0.45 higher than the starting voltage. With a bad battery on the backend I can make it shoot up instantly over 2 volts sometimes, so you can see that this isnt always an accurate test if batteries arent equal. By the way that is with a new 1.3 amp hour battery charging a 20amp hour (damaged). So you have to be careful/scientific regarding this particular test.

By the way, you want the least amount of amperage showing going to the charging battery. One of my better replications uses 1000ma on the front end and less than 120ma of that makes it to the charging battery, or so my analogue meters tell me. Like Ive mentioned before, you just cant be too certain in these circumstances, especially with pulsed DC.


You will find an easy way to measure peak voltage is with a very small uF cap (HV of course) these will charge up very quickly. You can get some great 3.3uF HV caps from inside the light bulbs Imhotep has shown us how to modify (CFL). Careful when measuring/shorting, they are tiny but can still give you a good zap!

I have now run the test with the batteries in reverse order; the voltage slowly fell after an initial rise.

Test 1) a 9 Ah charging a 7Ah
Test 2) a 7Ah charging a 9Ah

The results are very interesting. Although the battery drain was well above the C20 rate.

Total power used in test 1) 33.35 watt hours
Total power used in test 2) 34.16 watt hours
Total loss during the tests 0.81018 watt hours

Test1
9 Ah bat 7Ah bat
Start 12.77 12.4
End 12.33 13.04

Test 2 after resting the batteries
Start 12.52 12.64
End 12.99 11.86

Rest 12.77 12.14

The tests ran for 5 hours each

The source battery was being drained at a little over 0.5 amps
The input to the charging battery was 0.09 amps (this is what the meter showed)

Am I going nuts or is that an efficiency over 98%

Or have I missed something???

Mick

mbrown, have you tried the Radiant relay idea from Imhotep?

It could be exactly what you need.

byjoveoldchap yes i tried that several months ago, then i pulsed an ignition coil, then an arc welder and a good output was gained, but i damaged the relay with the welding machine (too many amps for the contacts)

When i have a good solenoid available i will continue with this one but i will also need a big battery bank to absorb the power otherwise i think the risk of battery explosion would be too great. another alternative would be a commutator powered by a small motor. When i pulsed the arc welder i fed the power into the low tension (output) windings the drain is huge on a battery. some people have used this to power Tesla coils to generate huge arcs

This is true Tesla style.

It is very easy to get massive outputs but be aware that this is lethal power.


Try to mach the drain on batteries and the input given to them to your charger, If you work your batteries too hard you will not gain the mysterious advantages to this type of charging and not only risk damaging them but risk explosion and damaging yourself.

Mick: fascinating results. Just not sure how you calculated the watt hours figures? I'd love to repeat your experiment but I don't know how to do that.

lan

I used a Bedini type fan. its output was low so i simply put an ignition coil in parallel with the power coil on the fan to get a bigger output.

I used four meters.
Volts input
Amps input
Volts output
Amps output

The tests ran for 5 hours each

I made a couple of typo errors in my spread sheet so my original posted figures are slightly different but the conclusions are the same

see attached

Ill try again