The Tesla Project

[Groundloop]

@armagdn03,

>>What is being argued could be filed under "improvements upon switching systems" or something similar.
>>Dont worry about improving upon switching mechanisms when the machine around which they have been built have not been shown.

If this is just a theoretical discussion thread about Tesla? Am I wasting time trying to find a switching solution to Wattsup circuit?

Groundloop.

[armagdn03]

Nonot at all, sorry if it came off that way, im just sayig dont get boged down in the details, big picture thinking, Actually being able to switch ac is very useful, and the optocoupled scr is something that can be bought in a package form or made with mosfets without freewheel diodes

[Kator01]

Hi Folks,

never ever place a MOSFET in a switching circuit in this configuration.

Please see attached pic I had sent to another user for the cap-switch-experiment

I have to add : .... increasing voltage at the inductor.

I will not argue on this. This is electronic-basics.

The gate-source-level must no be reduced by rising up the ground-level which will happen because of the reluctance of the coil.

Best Regards

Kator01

[wattsup]

@Groundloop

I understand fully what @armagdn03 is saying and I am glad he explained it because I was at a loss to know what to say. For me I was sure he did not mean to stop this or that but to keep in mind the ultimate goal.

Also, for me, the idea of building a device then hoping that the required switching system can just materialize is not a sound method.

Thanks for the last diagram. I am trying to get my head into the circuit but am having some trouble.
In your description you mention an optocoupler, a hexfet and two scrs but I only see one scr which is the IRL540N.

Also, I think @kator01 was referring to the 4N32 saying it should be on the ground side. I have used the IRF840 on the positive line with good results, maybe this is also good for the circuit.

[Groundloop]

@wattsup,

The IRL540N is a hexfet. The two SCRs is the BT151.

It is possible to use an hexfet at the positive line in this case because the
powering of the gate is relative to the transistor inside the opto coupler.
The back emf generated voltage from the coil is a problem, yes, but
is is my hope that this will not be a problem in this circuit because the SCR
will be closed when the back emf voltage goes negative. So when we shut off
the hexfet then the current through the coil will stop. Both SCRs will go
open circuit and no back emf voltage can or will be coupled back to the input.
The biggest problem as I see it is how to get both SCRs to start conducting
current. Even if we trigger the gates on the SCRs with a positive voltage,
then there is no positive voltage potential in the coil so the lowest (in the drawing)
SCR will not close to carry current because the top (in the drawing) SCR is not
closed yet. It is a catch 22 situation.  So, how can be give a small positive bias
to the coil without "destroying" the intention of the circuit? That is the question.
I will look into this and see if there is a solution.

Regards,
Groundloop.