Looking for IGBT with vgs < 2V

[braikar]

Hi,

Everything is in the title
I am looking for an IGBT with a vgs voltage of about 1V, but < 2V is also fine, but I wonder is this is even possible? The lowest I found is vgs +/- 12V.
Does anyone know if there are IGBTs with such low gate-source trigger voltages?

Cheers

 

[(*steve*)]

I would think what you're looking for is going to be like rocking-horse manure. I would doubt that any devices have even a Vgs(th) (if that's what it's called for an IGBT) this low.

Are you running from a low (2 or 3V) supply rail?

Perhaps you can describe a little more of the details and someone can come up with an alternative option for you.

As an example, 1 to 2V is enough to turn on a transistor and this could swing the gate by many volts.

 

[braikar]

Well, I'm not using a supply rail or anything at all, I'm trying to scavenge EMF radiation that is everywhere around starting from nothing.
I have a large (about 50m²) metallic roof which I'm using as an antenna for picking up the ambient EMF. I can't really tell what I am picking up, it seems I'm picking up some radio signals, some satellite signals, powerlines power etc.. If I look at the FFT of the signal I get from that roof, there are some definite peaks, one at 166 kHz, another at 183 kHz sometimes and other peaks that appear and disappear randomly. (can't go beyond 200kHz for the FFT on my oscilloscope )

Anyway, the signal I get is a mix of random stuff, oscillating quite quickly (I can't really measure any precise frequency) and it's varying between approx +/- 1V. So I'm trying to convert that into usable electricity and so far using a cockcroft walton voltage multiplier I was able to get voltages of 5-6V and I could go higher with more diodes. Also, since the oscillations are so low, using germanium (or schottky) diodes gives more voltage since the forward voltage is 0.2/0.3 V. Up to now it's providing me enough energy to light up one or two light emitting diodes continuously..

So I wanted to try using a boost converter to increase the voltage, but I don't want to use any external power, I want to trigger the IGBT using the random scavenged signal, and since it barely goes beyond 1V I need an IGBT with a very low Vgs value.

The circuit would be somewhat similar to that:

I'm not an expert so I don't really know which other transistor I could use which would act a a switch instead of the IGBT on that drawing. Because what I studied at university about transistors was always with dc supplies, without any supply I'm kind of lost on how to switch on/off a jfet, bjt,mosfet or anything else!

 

[(*steve*)]

Well, you're showing a power MOSFET in that circuit, not a IGBT.

Look for logic level mosfets, you might find something with a very low Vgs(th).

You're probably losing over half your power in the diode bridge. What sort of diodes are you using? D5 needs to be a schottky diode, and the other diodes probably should be as well.the 5uF capacitor should be placed in parallel with a 0.1uF capacitor, and the 5uF should be a low ESR device.

With all of this you're unlikely to get much power.

I'd consider using an RF transformer to increase the voltage as the losses are likely to be much less than in your existing circuit.

(You're not going to get much power out of this in any case -- you do know that, right?)

 

[GonzoEngineer]

I don't want to sound sarcastic.....but just how much current do you expect to get out of that roof?

You can't just boost voltage, you also need current.........

 

[jackorocko]

I don't want to sound sarcastic.....but just how much current do you expect to get out of that roof?

You can't just boost voltage, you also need current.........

actually even though I do agree with you, the one thing he has that neither solar nor wind can provide is a constant source. For what he is trying to do I totally applaud his effort. Use energy that is otherwise completely wasted. I would be very interested in seeing how this project ends up even if it is totally useless.