Use for the Tesla Switch

[nilrehob]

I think You're right. I'll stop this nonsense now.
Reuse of current is not possible by slow switching, which is comforting, it's too simple.

[nilrehob]

I took a closer look at Bedini's version today and redraw it omitting the controller for the switching.
It's quite different from the one in PJK's guide.
Six extra diodes, of which two looks unnecessary, and the two capacitors are turned around.

Does anyone know why B has chosen to do it in this way?

[Matthew Jones]

I suspect its for even flow to the batteries. Also allows for a smaller diode as oppossed to one big one.
The diodes take a beaten when switch rapidly.

Matt

[nilrehob]

I made a really simple TS with a relay and 12V 1.3Ah batteries and connected a large coil to it, switching at ~8Hz.
The coil was a unused roll of ~400m Cu-wire #23 so it had an air core.

The BEMF spikes was marvelous and I could lit a neon by only connecting one end of it on to anything in the circuit and the other end in the air, especially if I hold the other end it would light up nice.
The relay got crazy once in a while.
I moved the coil to another room, 5m away, but nothing changed.
The voltage on the batteries was jumping, probably not only up, not sure, none of my meters was behaving properly.

Not a very productive circuit I guess, but quite fun actually.

[nilrehob]

I have made some changes to my simple variant of the TS (and will make a video soon, have just prepared an account at youtube).

This one captures the spikes from the coil, although I'm not quite sure its necessary as there was spikes all over the place even before I added the diod's.

Then I put neons in series with all the diod's, just for fun, made myself a neon-sign a'la Vegas

[ashtweth]

nilrehob, thanks for the update look forward to the vids mate,

Ash

[nilrehob]

Two vids out!
Nothing too special, but still...
YouTube - Tesla-switch part 1
YouTube - Tesla-switch part 2

[Xenomorph]

@nilrehob : Nice effort to advance towards a solid state solution!
As of now, you are connecting ALL 4 batteries AT ONCE to the relay once the 555 switches, if i perceive it correctly?
Did you make a long-term test and did the batteries actually store the charge?

[Matthew Jones]

Thats nice looking.
Two issue with spikes you gotta watch is. Are they just Voltage Increases from the coil.
You can tell by watching the in and out waveforms seperatly if you have 2 scope leads. Whats going in to the coil and whats going out.

If they are BEMF spike you need to wire in a way to send the negative spike to ground or too a capacitor to seperate the energy. 2 spike together don't do you any good once in the battery. It took me a while of playing around to figure out. But if you look at a Monopole you'll see what I mean, 1 spike. The true spike will show up first the second will trail after. It might be either spike.
I don't know to switch them off solid state just mechanically.

Nice stuff
Matt

[nilrehob]

@Xenomorph

its switching just like a TS, bat 1+2 in series and bats 3+4 in parallell, then switching to bat 1+2 in parallell and bats 3+4 in series and then back again.

Its no use testing for long term yet as the use of a relay is not optimal at all.
With a relay you go -12 to 0 to +12 to 0 and then -12 again with long time on -12 and +12 where it should be the other way around with long time on 0 and short pulses on -12 and +12 just to kick the coil.

@Matthew

I don't understand exactly about the two spikes. Doesn't the diodes in the 2nd video take care of that?

[nilrehob]

@Xenomorph

In the current setup, on the four-pole-relay, I use one pole as on-off, two as on-on and one as off-on.
I have to get my hands on an second relay and another 555 timer (or two), i think, connect the two timers in some way (i have to study the 555 some more) to puls each relay in turn using three switches as off-on in each relay.
Then I will run it for a long-term test.

[nilrehob]

@Matthew

I've done some additional thinking , and yes, I'm pretty sure my setup with the diodes handles both spikes, the positive and the negative.
If that is what you mean?

[nilrehob]

@Matthew & @Xenomorph

BTW, I forgot to say thanks for the positive feedback, I'm just really focusing on this switch thing, thats all
I'm always like this, you'll see...

[Sephiroth]

@Matthew

I've done some additional thinking , and yes, I'm pretty sure my setup with the diodes handles both spikes, the positive and the negative.
If that is what you mean?

I agree... I think your circuit very cleverly handles the spikes

I am not yet certain of how the tesla switch maintains the charge in the batteries... not sure if I agree with Mat's interpretation, but then again he is one of the few who have reported a successful replication.

Personally I think it has more to do with battery resonance than charge recycling. Lets say 1 coulomb of charge flows through the circuit per switch: that means one coulombs is discharging BOTH the batteries that are in series, and the batteries in parellel are only receiving half a coulomb each. So two coulombs in total is being sacrificed on the series batteries and one coulomb in total is being recovered by the parellel batteries. Conventionally this system can not work by recycling current/charge.

Your circuit will have much higher efficiency in charge recovery (eg, 2 coulombs leave, 1.5 coulombs recovered), but will it produce the same effect that allows the tesla switch to operate? I don't know.

[nilrehob]

I agree... I think your circuit very cleverly handles the spikes

Thanks Sephiroth!

I am not yet certain of how the tesla switch maintains the charge in the batteries...

I'm not sure either, but I'm testing it as I write this, switching only when volt & amp gets low, it will take some days to do, especially since I have to compare the slow TS with conventionally having the 4 batteries in parallel (so I have to do at least two runs).

Personally I think it has more to do with battery resonance than charge recycling.

I agree. Resonance and the spikes seems most interesting to me.
I'm starting with the spikes though.

So two coulombs in total is being sacrificed on the series batteries and one coulomb in total is being recovered by the parellel batteries.

Isn't one coulomb going from the bottom battery to the top battery of the batteries in series, and then one coulomb from the top of the two to the batteries in parallel where it gets split in half?