Plasma Speaker

Hi there!

I'm also planning to make this project (also from instructables).

**broken link removed**

There is a small problem in this design i.e the MOSFET is heating up pretty badly.

I wanted to confirm if i could put another MOSFET in parallel (gate at pin 9 and drain,source across the diode).

Also in the circuit the flyback transformer rated current is about 5amps.

Does the power supply of the TL494 alsso have to be this rating?

Thanks!

Do you have the MOSFET on a heatsink? If so, how large?

No i don't have one yet. The main reason i wanted to keep another MOSFET was to reduce the size of the heatsink....

This is a new information. Did you try it? If so how is the audio fidelity and quality?

Mithrandir2008 said:

No i don't have one yet. The main reason i wanted to keep another MOSFET was to reduce the size of the heatsink....

Click to expand...

Adding a MOSFET will not reduce the size of the heatsink appreciably since the total power being dissipated would be the same.

Theoretically it should.

Basically power dissipation depends on the amount of current flowing through. So if i add another MOSFET i should be shunting the current and hence reduce the dissipation across "each" MOSFET. The total power would be the though.

What i'm asking is will the MOSFET blow or something (i'm not very good at analysis...)

Well semiconductors blow at very high temperatures, but its good to keep it under 80 °C.

You will need a medium sized heat sink for this.Because the mosfet will heat quite some. Aperantly the way the mosfet is used in the schematic it is switching its inductive load in quite inefficient way(Its also the simplest way).For driving inductive loads at high powers its best to use a LC resonant cirucit.