Solar powered pre-amp??

[nopainkiller]

I was looking at my little calculator today and saw that the solar panel is rated at 1.5 v.

Has anyone ever tried to make an onboard jfet preamp or something to fit inside your guitar? This would be easier than making one with a 9v and having to change the battery all the time. The small booster uses small amounts of energy, right? So would this work??

[52 Bill]

I was looking at my little calculator today and saw that the solar panel is rated at 1.5 v.

Has anyone ever tried to make an onboard jfet preamp or something to fit inside your guitar? This would be easier than making one with a 9v and having to change the battery all the time. The small booster uses small amounts of energy, right? So would this work??

Anything is possible, but I would think that there wouldn't be enough juice to handle the drive current requirements od high output pickups.

[nopainkiller]

High output? Do you mean active pick-ups? I remember reading a while back, about a JFET pre-amp thing inside a guitar. The article said power it with calculator batteries. I figured if that's enough to power it, why not a few solar panels. They're so small you could find somewhere or some way to put them on your guitar and it really wouldn't mess with the look. Unless you need like a foot long peice.

It sounds like a great idea, but I don't think it's been done, so it might not be possuble?

[R.G.]

Possible? Could it work? Sure.
Practical? That's questionable.

1. Voltage: Guitar pickup voltage is in the range of 100mV (low output single coils) to 2V (high output humbuckers). You're going to need more than the biggest pickup voltage, and possibly two or three times that. I would not like to design an onboard preamp on less than 6V. So you would need four of those solar cells to power it, best case. Better to count on six.
2. Current: Your calculator probably uses less current than a one-JFET preamp circuit, maybe hundreds of times less. The CMOS logic in calculators is very, very low current drain. Very. Again, more solar cell area needed.
3. Stage lighting: unless you play only in your bedroom, you'll be on some moderately dark stages a lot of the time. Maybe not enough light coming in to keep your solar cells producing enough voltage times current to run the preamp. I would not like to go hunting a spotlight just to keep my guitar making signal.A cure might be ... yes, even more solar cell area to catch more photons. Or only playing daylight gigs.

Solar cells are modestly expensive. Frankly, using rechargeable onboard batteries which are kept topped up with a charger makes more practical sense than trying to do solar cell powered preamps. IMHO anyway.

Good inspiration. It may be difficult to make work reliably, though. And when you step on stage, "reliable" means a lot to you. Or it should.

The devil is always in the details.

[nopainkiller]

hmmm, yea yer right I guess. It would still be kinda cool in a gimmicky way. I just don't wanna freakin open up my guitar to change batteries all the time. So I haven't built one. I's still like to look into it a little. Maybe just do it on a crappy cheap guitar. It'll be a cool toy.

[Enzo]

I guess all the time is a relative term...

I've been working on a solar powered flashlight, but have a few details left to work out.

[nopainkiller]

Bah! I'll still do it. It's gunna be great!