Joule Thief

[jeanna]

fascinating indeed.

and it can become really complicated to some because the energy is, sometime, not linear in time.
meaning that the energy level at one time is not always the same as at an other time.
ex: 1uA per cycle at 1 Hz = .5uA per cycle at 2Hz

and AC curve, the max energy level is only at the peeks.

I assume these are 2 different separate things, related but 2 different sentences.

Your formula helped me make some examples

at 220r   I got 193uA/Hz. at 95V   that = 18uW /1Hz
...
...
I just deleted the rest because I want to double check the decimals.

My assumption is that this provides me a basis for comparison between these coils. It is on a 1Hz basis that I am comparing them

So, if I have 18uw/Hz at 52KHz and 82uw at 35 KHz I can just calculate the watts per Hz and see what I have?

thank you ,

jeanna

[xee2]

I did some tests on NE2 neon bulbs. They seem to light and stay lit at 60 volts with 10 kHz pulses. I also did some tests on the 4 watt fluorescent tube and it seems to need at least 367 volts to light with 10 kHz pulses.

EDIT: Neon voltage may not be correct.

[xee2]

@ hazens1

It could have been better if I took more time on it. If you look close you can see a couple of spots where I had to skip an overlap on the pickup on the way back because the alignment was getting off.

Nice looking coils. I do not think your errors in winding will have any effect in performance. I am looking forward to your test results.

[xee2]

@ jeanna

Watts = amps x volts

Frequency does not effect how many Watts there are. Amps is the number of electrons flowing through wire per second. Thus watts is actually electrons x volts for each second. This number does not change with frequency unless there is something in the circuit that is frequency sensitive. If you divide watts by the number of cycles per second, then you have the number of watts per cycle. For a given number of watts, there will be less watts per cycle as the frequency is increased since the number of cycles per second increases with frequency.

Perhaps this will help. Perhaps it will confuse you. But I hope it will help.


Now to really confuse you. Since it is possible to measure amps and volts over very short periods of time, then they can be measured over small parts of each cycle. When this is done, since the voltage is highest at the peaks of the AC cycle, and since watts is amps times volts, then therefore when the watts are computed over very short periods of time during each cycle there will be more watts at the peaks of the AC cycle than at the zero volt points. But all of these small periods of time are just part of the total amps and volts flowing through wire per second. For AC the effective "average" voltage is the RMS voltage. So for AC the volts in the equation for watts is the RMS voltage.

watts = amps x Vrms

[jeanna]

Watts = amps x volts

Frequency does not effect how many Watts there are.

I realized when I read your reply that I had forgotten to finish my formula sentence. What I meant to write was:
193uA / 1Hz x 95V = 18uw /1Hz
The next step would be to multiply this per Hz amount by the number of Hz so, I would then multiply 18uA x 52,600 times per second that this peak occurs. In this example it would give 0.946mA/sec.

It may not be the same as what a rectifier would see or what a dc would show in this same sort of exercise, but it would be a similar basis for comparison. One might even find that the mA draw from the battery has a relationship to this number.

and it IS necessary to add the "/Hz" label. So watts per Hz could should be able to be compared to other watts per Hz. I could do this privately, but even if it is not kosher, it might give someone else a good or better idea.

Thank you for supplying this additional information (and the experimental information as well).

jeanna

edit

I did some tests on NE2 neon bulbs. They seem to light and stay lit at 60 volts with 10 kHz pulses. I also did some tests on the 4 watt fluorescent tube and it seems to need at least 367 volts to light with 10 kHz pulses.

And did you happen to note the amps draw at that time?