Quote from: Void on May 15, 2013, 10:32:33 AM
Thanks Lawrence. I actually have two DSO scopes. A 50MHz Hantek USB peripheral plug in type scope, which is what I  used on my previous tests on my joule thief circuit here, and a 100MHz Siglent 1102CNL scope, which is what I am going to use to run tests on your boards, since the Siglent should be a better scope overall, and it can be set down to 2mV/div, whereas my Hantek can only be set down to 10mV/div.

I did some testing with my Siglent scope yesterday. I warmed up my scope for 20 minutes and then configured each probe/channel to DC, x1, and 2mV/div, and then grounded the probe tips to their ground clips. There was some DC offset showing on each channel, so I ran the self-calibration function on my scope. (My Hantek scope instructs connecting the scope probe tips to the ground lug on my scope when running the self-calibration, but my Siglent scope instructs to disconnect the probes from the scope when running the self-calibration). With the scope probes again connected to the scope, I then double checked that each probe/channel was still configured for DC, x1, and 2mV/div, and then grounded the probe tips to their ground clips. Channel 1 was showing no offset, but Channel 2 was still showing about + 0.6mV of offset on the 2mV/div setting with the scope tip grounded to its ground clip. I then left my scope turned on overnight and then re-ran the self-calibration function on my scope in the morning, and then rechecked the Channel 1 and Channel 2 DC offsets with the probe tips grounded. Both channels are now showing very close to zero offset (with settings: DC, x1, and 2mV/div). Just wanted to mention this in case it helps with your scopes. I am not sure if leaving the scope to warm up a lot longer helped, or if you just sometimes have to run the self-calibration a few times and keep checking for the least amount of DC offset.

By the way Lawrence, I read that Siglent is actually the manufacturer of Atten scopes, so our scopes should be very similar. The self-calibration method I describe above should be very similar if not exactly the same for your Atten scopes. What model of Atten scopes do you have?

I have Atten ADS1062CA and Atten ADS1062CAL.  Previously, I always thought that the warm up time is to get the Atten to normal room temperature of around 20 degrees C.  In cold countries, the warm up time may take longer.  But I can easily turn it on overnight.

Did you detect any spikes at all with your tests?  I can easily detect them.  Example - see reply 835.

Quote from: ltseung888 on May 15, 2013, 03:22:22 PM
I have Atten ADS1062CA and Atten ADS1062CAL.  Previously, I always thought that the warm up time is to get the Atten to normal room temperature of around 20 degrees C.  In cold countries, the warm up time may take longer.  But I can easily turn it on overnight.

Did you detect any spikes at all with your tests?  I can easily detect them.  Example - see reply 835.

Hi Lawrence. Warm up time is to allow time for all sensitive components in the circuitry to reach their steady state operating temperature. 30 mins. to 1 hour should be long enough. After sufficient warm up time, if you test the DC offset for each scope channel as I described in my previous post, and then try the self-calibration, and then retest the DC offset, I would be interested to hear what kind of DC offsets you are measuring on each channel.

I am not detecting current spikes like you show in those scope shots in my circuit.

I also tried another couple of informal tests where I changed the collector winding turns count to 18 turns and also to 39 turns, and I did not see any AC current spikes (or any zero crossing at all to speak of on the current waveform), and the efficiency of the circuit also did not change more than about 1% with these different collector winding turns count changes as well. Efficiency stayed within +/- 1% or so of about 70% with collector winding turns counts of 18, 28, and 39 turns. Changes to the collector winding turns count does noticeably change the frequency of oscillation however.
18 turns - 71.53 kHz,   efficiency = 70.93%
28 turns  - 57.14 kHz,  efficiency = 68.93%
39 turns - 43.48 kHz,   efficiency = 71.29%
I was surprised to see that the circuit efficiency seems to have remained about the same for these different collector winding counts.

Note: I was using the RMS measurement feature on my scope to make these measurements as it was just an informal test to see what effect changing the collector windings turn count might have on circuit performance. I will use data logging and instantaneous and Average power calculations when doing any tests on your boards. I made the above measurements using my Siglent scope, which may be somewhat more accurate than my Hantek scope. That may account for the difference of measuring around 70% efficiency this time and measuring around 75% efficiency previously with my Hantek scope. It might also be that my ferrite core which is in two halves and is just taped together, has separated a little bit more than before. I really should bolt the two halves together tight so they can't move, but these tests I am doing right now are just informal to get a general idea.

I turned on the Atten for over an hour before doing anything.  The first thing is to press the default setup button and do the calibration.  I then set the reading to the ones normally used.

The five boards were tested:
Board 89, 124, 125, 118 and 119.

The Input Power supply was adjusted so that the LED was just turned on.  Here are the results.  All five boards showed current crossing 0 ref line.....

Quote from: ltseung888 on May 16, 2013, 02:25:55 AM
I turned on the Atten for over an hour before doing anything.  The first thing is to press the default setup button and do the calibration.  I then set the reading to the ones normally used.

The five boards were tested:
Board 89, 124, 125, 118 and 119.

The Input Power supply was adjusted so that the LED was just turned on.  Here are the results.  All five boards showed current crossing 0 ref line.....

That is very interesting Lawrence. Thanks for checking the calibration on your scope. I don't really understand what is causing those AC current spikes in your scope shots. Your input current traces are very different from what I see in my circuit. I look forward to running tests with your boards to see if I see the same sort of results.

This is getting rather ridiculous, don't you think?

Are you really looking for, and trying to reproduce, some kind of OU evidence that only shows up with the cheapest possible DSOs used incorrectly? With absolutely NO concurrent validation (a technical term meaning evidence of OU from some OTHER experimental or measurement technique running alongside the Atten measurements)?

Note again, that after all this time, the definitive experiment is still not being done. Charge a known capacitor to a known voltage. Then you know precisely the energy available for whatever. Use this capacitor to run the JT circuit while monitoring its voltage and the time accurately. Monitor the output power in your favourite manner. When the capacitor has dropped by a known voltage increment, you will KNOW just how much energy you have put into your circuit, and you will KNOW for how long.... thus you will KNOW, not guess or interpret, just how much input ENERGY you are dealing with during that time. This figure can be directly compared to the output power, or more precisely to the integrated output power over the time interval concerned (the output ENERGY).

It will do no one any good if I do this measurement. It must be done on several boards that Lawrence claims do show OU behaviour, preferably by Lawrence himself, but anyone who has an "approved" board, an oscilloscope, a stopwatch, an accurate voltmeter, and a bunch of capacitors can do the work in a day or two with enough runs for statistical significance to result IF there is anything to see.

When you see that every capacitor you try results in efficiencies of under 100 percent, then you can start resorting to your special pleading that "the robust and confirmed OU effect only happens with batteries. No, not those batteries, or those, not just any batteries, but only rechargeable batteries of specific chemistry and manufacturer, and only when they are between 0.341 and 0.351 volts".... and only when they are pointed northeast, on Tuesday mornings, when the weather is clear......

Whatever, dudes.