problems with timeinglight,stroboskopeffect

[Yaro1776]

Impact of Strobe on Tuning

Well I took BobZ recommendations and applied them to my current TX 8 trans board, however with only 5 coil "bottom" wires attached to the board - same high performance wheel, but with the gap decreased by 0.25" to ~ 0.175" from the previous setting of ~0.200"'. Reason for coil wire removal is the high fixed base resistance of 470 ohms leaving very little play room.

This run started w/o the resistor and with a pot for resistance adjustment. The initial speed was 198 rpm with charge amps at 0.64 and primary amps at 1.07. The charge voltage was at 13.94. The strobe was showing two very distinct bands. Sorry no video capability here as yet - there is a very interesting progression from here.

The resistance was increased in progressive steps estimated at 10 ohms each. As the resistance was increased the wheel rpm went up to a 212 value and then began to decrease down to 193. The charge voltage dropped by increments down to 13.17, while the charge and primary amps decreased to 0.32 and 0.49. The strobe showed that the two bands produced by the coil firing were increasing in width with the last read starting to flutter a bit.

Sooo, the resistance was increased a bit more (measured at 43 ohms) and here the charge voltage began to climb to 13.24, while the amps increased to 0.37 (charge) and 0.53 (primary). The wheel rpm dropped to 177. The interesting part is that BobZ pointed this experimenter to find the transition points between the 1, 2 and 3 spikes. This last data set distinctly showed the flutter in the firing points - this area of pronounced flutter (multiple unstable spikes - 3 spikes perhaps?) produced an unexpected jump in output as noted above. Truly worth the effort and time to see this happen after going in circles for a while.

Please note that this config was run twice with similar data values and spike behavior. Here the experiment is concluded for the day. More tomorrow or soon.

Yaro

[Yaro1776]

I do have an identical older wheel that is not tuned for max rpm due to the bearings etc. The frictional component on the wheel is greater - I will pull it out of the barn and see how it reacts.

Thanks again,
Yaro

[BobZilla]

Another way would be to add mechanical resistance. A fan, a genny coil, some playing cards attached to the spokes, whatever you can come up with, resistance can be added to the wheel instead of through the trigger. Ideally you would do it with a pot on the trigger but you have those 470's on base so you don't have as much wiggle room there.

Anyway it is not crucial but just something to play with.

[Yaro1776]

That is an interesting method worth further investigation. I am hampered by the fixed base resistance (470 ohms) on the TX 8 trans board, however I can play with the method to a limited degree by removing an active coil wire input to the board. The progressive removal of coil (bottom) wires changes the overall rpm and amps, so there may be some room to play with this using a pot. I have noted in my testing that there is a very strong correlation between the charge voltage and amps values. So this volt value really helps to get a sense of change without having to put on the clamp on transducer for an amp measurement. The bike wheel speedo is great for seeing the immediate changes in rpm after modifying the config on the fly.

Thanks for another great tip!
Yaro

[BobZilla]

Good to hear it worked out for you.

Now that you have a light I will tell you something to tune too for a little insight.

tune your machine on two spikes and back it off until 3 spikes show up, then back to 2 just barley in. Notice your charging rate when you are just at the convergence point between spike counts. Now turn it up a little at a time untill you are about half way between 2 and one spike, notice your charging that way.

The same can be done within any spike count you like but the point I am trying to make is you want to find the spot just as it changes and looses a spike then go half way beyond that towards the next. In the middles of your spike count so to say, not the end, not the beginning but in the middle.

Try it out and see what you think.

[Yaro1776]

Hey BobZ,

Everything worked out fine with the LEDs. I picked up one clear and one blue bulb type - square one and red were unavailable. Attached a piece of reflective tape on the base of a spoke - that seemed to work the best since the wheel is shiny Al alloy. Observed the brightness change along with change from two spikes to one as tuning resistance changed.

Thanks again, this is very helpful to my tuning efforts,
Yaro

[BobZilla]

No problem.

You can also monitor your trigger wire in the same manor, one lead on "top" and one on "bottom" It will basically show you the same thing but some folks like to look at it that way. The difference would be you would be looking at when the transistor base receives,, the trigger signal,,, what I described is looking at the reaction of that which is the actual coil charging and discharging. you can use either way.

I prefer to monitor the actual power winding because that is where the spike lives, you can also get indications of certain things by noticing the brightness of the Led's at different tunings. Once you get a timing light on your system some things wil become more clear as you try to find your best tuning.

Don't leave it hooked up all the time though, it will steal from your charging. That's why i put gator clips on mine and hook up on that primary PoS post in the front. i do not want to chew up my power winding by putting it on and taking it off over and over. I leave the back one connected and just clip on the front one when needed.

[Yaro1776]

Excellent clarification with the pics. This will flesh out the timing light procedure for myself and others.

Nice execution on your dual coil effort - I will continue to watch your thread on this.

Thanks for your effort!

Yaro

[BobZilla]

Yes if you look at where your coil wires connect for the power windings you will find that all the tops trace back to the primary pos rail and you want one clip for your LEd there. The other clip for the led will go where the bottom of those wires are which is on your collector rail BEFORE the diode that goes to the charge pos.

On my board I have a terminal block with rings on my coil wires so you can see in the picture below I have one connected to the pri pos ( the lower one in the picture,, and the other is on the bottom side of a power winding.


I have the red and the blue so I can see both polarities and you can see the resistors on there.

To make this one i used some gator clip wires that had a broken clip so I cut that off and attached my Led's to those ends. Actually the white clip leads are connected to an extension I made with some small speaker wire but you get the idea.




*EDIT*

Adding a top view because I realize you cannot really see whats going on in the back on that last pic....

[Yaro1776]

Comprende

BobZ,

If I understand you correctly the the Primary (+) or "top" point at the coil juncture is one connection for the LED, with the second LED connection being the TeslaG board connection for the coil "bottom" or one of the single wire connections to the board.
Tomorrow I will visit my local Radio Shack for the LED and resistance suggested and give it a whirl. More later...

Thanks for the explanation and specs,
Yaro

[BobZilla]

I make my light with two LED's one red, one blue. Wire them in opposite polarity of each other so that one will catch the forward voltage and one the backward. i prefer the little square kind that are high power and use at least 300ohm resistance but this will depend on what led's you use.

Connect across the coil. What this means is at each end of the coil so your tops are connected where,, the primary POS,, the Bottoms are where,, to the transistor collector BEFORE the diode.

think of it this way, the coil has energy passing in two directions through it. The diode only lights up in one direction so you want to be connected "across" the coil to detect the voltage through the coil.

[Yaro1776]

Can someone clarify with more specific detail the connection "across the coil". Where are the LED wires placed?

Yaro

[forelle]

forelle,
"I have hooked up the Led with 300 ohm resistor on Anode to Collector and Cathode to Emitter."
The LED should be across the coil not across the transistor!
Martin B

Thanks that was my mistake,now its clear.

[Martin B]

forelle,
"I have hooked up the Led with 300 ohm resistor on Anode to Collector and Cathode to Emitter."
The LED should be across the coil not across the transistor!
Martin B

[John_Koorn]

forelle,

changing the base resistance will determine when the transistor switches off. You should be able to see the angle that the transistor switches off with your timing LED.

John K.