Use for the Tesla Switch

[Donald Haas]

Thanks Matt,
I greatly appreciate your taking some time to encourage and provide info.
bro d

[Matthew Jones]

Its no problem.

Anything you need post and keep working. It will pay off I promise you. I wish the whole thing was more predictable. Seems alot of people have hap hazardly put these things together and it worked out but the ones who really try hard sometimes have to really try hard.

So anyway I'll do my best to help.

Cheers
Matt

[Donald Haas]

Thanks Matt,
I'm using the radio shack transformer that you recommended in the manual.
#20 wire.
The primaries are .46ohm and the 2ndary is .56ohm.
Since I rewired it the tranny heat not an issue.

Not sure how to look at the "recovery rate".

Thanks,
bro d

[Matthew Jones]

Run the system for an hour. Watch the current going in the transformer and coming out. You can look at the voltage too with a scope.
You can use a bridge instead of the transformer and see if the loss is as high, by going only one way. Just see if what you take out of one side migrates to the other. Voltage is an indicator but it should hold from side to side.

Check the 2 top batteries make sure they aren't going much over 14.5 while running. That may be when you want switch your batts and not when the batts get low. You might be loosing power from over charging as well.

Just try checking as much you can to find out why your loosing.

Worst case your batteries are just not coming around. It does happen but rarely. Don't assume that the problem just keep running the system to see.

Matt

[Kepszlok]

To Matt:

I do built the small version of your switch (the optocoupled version from page 25) with using the pulse source from my previous circuit.
I'm using a different transformer (230V - 2*16V toroid) because it was just lying around and with it, i may be give enough voltage to run a normal lamp or something. Currently there are noting in it's primer side.

So what i get:

-Connecting 3 batterys:
There are around 3V square wave on the toroid secunder, primer voltage goes up to 50V. The frequency for maximum output was around 1300Hz.
If i test the other side, the values are the same.
-connecting 4 batterys:
Voltages drops down to 1V secunder voltage. Seems like swapping one of the secunder's wireing does not affect this.


So we started first to debug the 3 battery setup. We removed the toroid from the system, and replaced it with a 12 ohm power resistor for easyer measuring. Voltage in the resistor was the same as in the toroid's secunder.

At the PNP's collector (between the NPN's emitter) we measured ~1.3V square wave. But between the NPN's there was only 200mV square wave, seems like the transistor was not fully open. We was tested with bigger and smaller transstor pairs, tryd smaller resistor between them, but the BE voltage remaind ~200mV.
I attached the Tina simulation of this, but the underlined voltage are obiously wrong in the simulation.

Have you got any idea about what cen be wrong?

[Matthew Jones]

To Matt:

I do built the small version of your switch (the optocoupled version from page 25) with using the pulse source from my previous circuit.
I'm using a different transformer (230V - 2*16V toroid) because it was just lying around and with it, i may be give enough voltage to run a normal lamp or something. Currently there are noting in it's primer side.

So what i get:

-Connecting 3 batterys:
There are around 3V square wave on the toroid secunder, primer voltage goes up to 50V. The frequency for maximum output was around 1300Hz.
If i test the other side, the values are the same.
-connecting 4 batterys:
Voltages drops down to 1V secunder voltage. Seems like swapping one of the secunder's wireing does not affect this.


So we started first to debug the 3 battery setup. We removed the toroid from the system, and replaced it with a 12 ohm power resistor for easyer measuring. Voltage in the resistor was the same as in the toroid's secunder.

At the PNP's collector (between the NPN's emitter) we measured ~1.3V square wave. But between the NPN's there was only 200mV square wave, seems like the transistor was not fully open. We was tested with bigger and smaller transstor pairs, tryd smaller resistor between them, but the BE voltage remaind ~200mV.
I attached the Tina simulation of this, but the underlined voltage are obiously wrong in the simulation.

Have you got any idea about what cen be wrong?

Some toroid transformers are wound for 1 way use. They almost act like a diode. You can only power one side. Trying to power the lower side is like adding a load and draws down the potential.

Try an EI core or just a spool of wire.

Matt

[Kepszlok]

Some toroid transformers are wound for 1 way use. They almost act like a diode. You can only power one side. Trying to power the lower side is like adding a load and draws down the potential.

Try an EI core or just a spool of wire.

Matt

So you sad, a proper transformer will let the switches fully opening? We had no luck with resistor (but tested it only with 12 ohm).

I will be again holiday for a week, but aftert that i will try other transformers.

[Matthew Jones]

As far as the transistors opening if you followed the instructions for testing while assembling everything would work. With those instructions you should be able to isolate exactly whats wrong. If your switch's aren't opening you didn't use the recommended transistors.

You'll have include info on your transistors if you changed the recipe.

Matt

[Kepszlok]

Yes i do followed the instructions. I get positive results from the initial switching test with a multimeter then moved forward.

I used MJE 15032 and 15033 transistors (250V, 8A, 50W), then tryed MJE 13009 (400V, 12A, 110W) and also tryd much smaller ones MJE 340 and it's pnp pair (300V, 0.5A, 20W).

[Matthew Jones]

I still don't understand all your your explanation of the measurements but sounds to me that the problems mostly are in the toroid transformer. So work on that if you can.

But keep posting when you get a chance, I'll help the best I can.

Cheers
Matt

[Donald Haas]

Questions

Hi Matt
#4 batt shows .8A and #2 batt shows .5A at the neg terminals under load.
I've ruled out the following as the cause by testing.
Trannys
Diodes...test
Batts...switch position
Transformer...swap primary connections
Arduino...swap outputs
Speed...ratio remains at different pulse times

Another question:
The voltage on my upper batts does not change under load.
Are they supposed to increase in voltage?
Thanks,
Bro d

[Matthew Jones]

Ya Ideally you would have about 13.8 v on the top batteries and 12.2 on the bottoms. Ideally. I have seen the system run at 14.5 on top and 11 something on the bottoms. That tends to be when my deep cycles balance out, then they just jump around in the hundredth of volts up and down.

I used some car batteries for while and they would balance out upwards of 15v on top and 11.5 v on the bottom.

You are getting AC type current out of the transformer right?

Matt

Hi Matt
#4 batt shows .8A and #2 batt shows .5A at the neg terminals under load.
I've ruled out the following as the cause by testing.
Trannys
Diodes...test
Batts...switch position
Transformer...swap primary connections
Arduino...swap outputs
Speed...ratio remains at different pulse times

Another question:
The voltage on my upper batts does not change under load.
Are they supposed to increase in voltage?
Thanks,
Bro d

[Donald Haas]

Hi Matt,
getting AC out of the transformer.
decided to try and see if I could pulse a pair of batts in parallel with series connected batts. put the parallel pair between the four batts in your simple TS setup. then connected the output from the both alternately pulsed series pairs into the paralleled pair.

On the first attempt the paralleled pair went from 12.5v to 15.2v in about 2 minutes. It depends on the size of the load on the transformer. cut the load at the transformer by 2/3 and that pulls less amperage from the series pairs.

The top batts of the in series pairs are much lower voltage than the bottoms
At last check the tops were at 12.4v and the bottoms were at 12.74.
Don't understand that. I thought maybe the diodes? removed them and no change.
They started at fully charged for experiment (parallel pair was discharged to 11.3v).

It looks like I should get much more output from the outer 4 batts with the charging and the 16W load then could be expected at a C20 rate which is only a 4W draw.

can all most asume that you tried it this way.

It's a good experiement for me because of pulsing a pair in parallel with no additional switching.
Thanks again Matt for being here.
bro d

[Matthew Jones]

Well why you are experimenting you may try to reverse your batteries in the setup and see if it helps. So in other words the positives are hooked to the transformer. The batteries may stabilize better in that direction.

I have pulsed from side to side. In fact the Benitez circuits (Patents) do that very thing.

You gotta watch the heat when doing that, especially in the transformer. Open coils like you would use in a Monopole work real well and if driven at a rate in which the current per pulse is low you can produce some pretty neat results showing extra work done. But you have to watch out for the big transients they will burn switch's out real quick.

Matt

[Kepszlok]

I still don't understand all your your explanation of the measurements but sounds to me that the problems mostly are in the toroid transformer. So work on that if you can.

But keep posting when you get a chance, I'll help the best I can.

Cheers
Matt

I'm back with some result. My prior scope pictures was mostly bad because of faulty connections. Now the whole switching part of the circuit works how it shoud be, perfect square pulses flows to the coils.

After trying 5 different transformer in every possible way, now i see this circuit will only work well with CT / isolator transformer with low dc resistance (along with Xl parameter i think) on both coils.


For me the cheapest way to get a suitible CT with two secunder coils is to build it with my friend. But to do that I woud like to ask something about the modified transformer what you described in your guide.
The basis was the CT heavy duty transformer:
110V - 2*25.2V, 2A - this gives V2/V1 ratio to 0.23

After the modification, what are the new values? I found it hard (at least for me) to follow what you ar duing with the transformer after the removeing of the plateing. I coud realy use N1, N2, N3 values along with their resistance.