Ghazanfar Ali Generator - Utlilizing trapped energy

[Groundloop]

@Groundloop
No the 12 V Bty will not be charged if you connect it instead of C2. The minimum driving voltage for the device must not be less than 24 V as an initial charge in C2 whether 150 Ohms load is connected or not. I did not test this situation but my hypothesis says that i may not work in case of 12 V Bty. But u can try.

Ghazanfar_Ali,

Thanks for taking time to answer my question.

I have built the circuit now. Did test the circuit on a 12 volt battery and the battery did not charge.
I will try 24 volt also. But first I will build a 555 driver circuit for the mosfets.

GL.

[broli]

Ghazanfar_Ali,

Thanks for taking time to answer my question.

I have built the circuit now. Did test the circuit on a 12 volt battery and the battery did not charge.
I will try 24 volt also. But first I will build a 555 driver circuit for the mosfets.

GL.

Can you please share the specs of your circuit, capacitance, inductance, turns, wires used...

[Mannix]

I am thinking that if we increase the voltage, the wire resistance may be less significant in the real circuit ..as in the  simulation.

However i will try again as soon as I get 18 uf of hv caps

[gyulasun]

....

Also what he said:

seems to be very important, as this zener diode gives the LC circuit always a kick.

....

Regards, Stefan.

Hi Stefan and Ali,

There is no any Zener diode across the output side of a power MOSFET i.e. between its drain and source electrodes. 

However, there is a so-called body diode between the drain-source electrodes, always in reverse direction with respect to the drain-source needed polarities.  This body diode is unavoidably created in the manufacturing process, see Fig. 1 and Fig. 2 of this paper here:
http://www.ixysgreen.com/Documents/AppNotes/IXAN0061.pdf 

This means that if you have a 200V max drain-source voltage rated n-channel MOSFET, the body diode is reverse biased all the way up to 200V as long as the drain gets max 200V positive DC or peak AC with respect to the source electrode. The moment the drain voltage goes negative with respect to the source electrode, the body diode gets forward biased (if the voltage difference gets higher than 0.8-1V of course in the forward direction) so current can flow via the body diode, regardless of the control voltage between the source-gate electrodes.
Of course, if you exceed the max 200V drain-source voltage rating the manufacturer defined for a particular MOSFET type, then the device will gradually start conducting current between its drain-source path, either via the reverse biased body diode or via the drain-source electrodes, bringing the MOSFET gradually or suddenly into a destruction process.

Gyula

PS:  Quote from the link: "The body diode is convenient in circuits that require a path for the reverse drain current
(called “free wheeling current”) such as half-bridge and full-bridge converter circuits in motor control applications".

PS2:  You can "neutralize" the body diode by using an outside diode in series with the drain,  this diode's cathode is connected to the drain electrode and the diode's anode will be the "new" drain electrode,  (use a fast recovery diode with correct reverse voltage and forward current ratings).  Of course this extra diode (if needed at all) increases the MOSFET switch's power loss ( which is the forward bias voltage drop times the forward current).

[poynt99]

There is no any Zener diode across the output side of a power MOSFET i.e. between its drain and source electrodes. 

Hi gyula,

Wouldn't you agree that every diode is technically a "zener" diode?

IOW, all diodes have a reverse breakdown voltage, but the difference with zeners is that they are engineered to have a specific (usually a relatively lower) breakdown voltage. And we normally include a series resistance with them to ensure they don't burn up.

I've seen MOSFET symbols with a zener rather than standard diode pictured.

Some MOSFETs are "avalanche rated" meaning they can tolerate a certain degree of avalanching in the body diode (the IRFPG50 is an example).

Regards,
.99