Tesla Switch need help

[plengo]

So this morning my 3 battery switch stoped running and all the batteries were at about 5 to 8v. I only stopped because the SSG will keep spinning but not really creating anything usefull now.

I outputed in all this 2 and 3 batteries systems 53.8watts of power. I usually charge each battery using a wall mart set at 12v and 100ma via the SSG. I run it for about 12 hours and sometimes for 24 hours. So right now I have no clue really how much power I put in those batteries before these runs.

This was just the preliminaries and now I will have to do the same I did for the SSG which is: measure how much I put in the batteries and how much comes out. I am impressed that I took out 53watts. If I had all 4 batteries fully charged they would, based on previous charges, have about 115watts of power in all 4 together. I took 53watts out measured so in worse case scenarios we have here a horrible less than 50% efficiency. But the reason for this first test was to really see if it would run at all.

So I think it was a success so far that I ran it for so long. Many things are strange. Connecting the output of the SSG into different batteries of the 3 swtich would produce extreme amout of power for 1/2 hour than go down. Switching again, it would happen again, and again and again. This system is very difficult to work with. But surprising too.

Now I am charging the batteries and keeping track of how long and how much they are taking IN. So I will run again the whole process and have a baseline this time. Cross fingers.

Fausto.

[Thaelin]

All:
  Well here is a simple way to get a 180 degree out of phase trigger for both sides from just a sine wave.
The diodes will inject a small pause between for the break before make. Nothing better than simple.

thaelin

Cant upload bitmaps so here is a text version of it.


                       |------------>|--------   Positive going signal
-----------------------|
                       |------------|<--------   Negative going signal

[Groundloop]

[EDIT] Deleted.

[Groundloop]

[EDIT] Deleted.

[gyulasun]

Does anybody know if there exist power FET transistors without internal diodes?

Hi,

Unfortunately there isn't...    it is the manufacturing process for power MOSFETs that creates the internal diode.

However you can place a similar high speed/ultra fast diode in series with the drain, the diode's cathode is to be connected to the drain of the power FET and the diode's anode will be the 'new drain', I assume here an N channel FET.  This way this extra diode prevents any (reverse) current flow whenever the internal diode would conduct.  The price to be paid is the power loss on this diode (forward voltage drop times the switch-on current)

Or you could use bipolar power switching transistors instead of MOSFETs if you wish,  there are no internal diode between collector and emitter.

rgds,  Gyula