Kapanadze Cousin - DALLY FREE ENERGY

[NickZ]

  Grum:
   I did try the two transistors, but I don't think that the turkey will be done by this Christmas time. Maybe by next year. As I could only get a 110v 7 watt bulb lit with them, but not any higher wattage bulbs. I also tried different caps, and chokes, but it looks like it works best when using no caps at all. I could only get 35 volts at the bulb, same as when using the fets, but they lit up two 50 watt bulbs previously.
  Anyways, I'll keep at it...

[SeaMonkey]

Most experimenters who attempt to get
the push-pull MosFet Oscillators working
will ultimately discover how delicate Silicon
Power MosFets are to being improperly driven.

If the drive signal exceeds 15 Volts then the
Gate Protective Circuitry will be destroyed
which leads to the MosFet itself being destroyed.

If the gate drive signal goes substantially negative
for an N-Channel MosFet then the Gate Protective
Circuitry will be destroyed as well.

It is very common in experimenter circuits for the
Gate Drive Signal to not turn the MosFet completely
OFF or not turn it OFF rapidly enough, in which case
the MosFet will become extremely hot and quickly
expire.

The solution to the Smoking MosFet syndrome in problem
circuits is to either

(a) re-work the MosFet Drive elements in the
circuit to assure that the MosFets receive adequate
drive to turn them ON quickly and, most importantly,
turn them Fully OFF very quickly,

(b) or use MosFet Driver Chips to provide the very
best drive signal to the MosFets.

It may also help to use the new Silicon Carbide
MosFets as they're much more durable, can
withstand incredible abuse and will tolerate
higher drive voltages of both polarities.

They're a bit more expensive than the mass
produced conventional MosFets but in the
final analysis may save some hard earned
legal tender.

[skywalker66]

@SeaMonkey

(c)  Isn't bad at all to use a current limitation supply bellow maximum current rated for FETs.

Sometime these royer or mazzily configuration stop oscillating especially when LC tank is low Q, or when  L is hardly loaded as the primary of a transformer. When such circuitry stop oscillating both fets remain in conduction, and then without a current limitation, bumm!

[NickZ]

  Although my last build of the transistor Royer circuit is not an award winner, only rather dimly lighting a 7 watt bulb. It did also charge a second 12v 7 aH battery, at the same time. This was due to a third 6 turn winding on the yoke core, which when a diode was placed on it, was able to charge a dead second battery. 
But, the idea is for the Royer to self run itself by keeping the run battery up, at least somewhat. Of course if the input power was like 24 volts, the output would also be brighter, and further possibly able to keep the run battery up.
However, this transistor version will light the small bulb even with 12v, and only 500 mA., also.
Anyways, it was all I could do for now, until I obtain more Fets.
Nothing lost, but nothing gained...

  Sea Monkey: Thanks for your comments.
  It is also true that if the fets won't oscillate, for whatever reason, they burn up in a blink of an eye.

  Itsu:  Lets just keep trying to get this to work...  I also tried to get this last circuit to go into second oscillations, but it seams to need more juice to kick it into that higher output frequency.

[Hoppy]

  It is also true that if the fets won't oscillate, for whatever reason, they burn up in a blink of an eye.

 

Only if you don't limit the supply current.