Someone told me...

**dmurray14** · 01-22-2005, 08:36 PM

I need to get 7vdc to power my TV tuner. I was going to buy a 12v to 7v adapter but someone told me that if I used 12v+ and used 5v+ as the ground, I would end up with 7 volts. Is this true? I don't want to fry anything, but if this would work, it would be great.

Thanks
Dan

**linuxguy** · 01-22-2005, 08:38 PM

Yea you can do that with an AT power supply.
if you dont believe me check it with a volt meter.

**strohmrs** · 01-22-2005, 08:50 PM

It works great for slowing and quieting fans. I'd be very cautious with a TV tuner. With a different ground reference anything grounded on the tuner cannot touch a ground on the PC or vehicle. Without a proper ground there may be an issue with interference as well.

**strohmrs** · 01-22-2005, 09:12 PM

On second thought, I highly recommend you do not even try to do this. Get a proper power supply. I'll expand on what my concerns were above.

If you use 5V as the ground then any ground point on the TV tuner will be at a 5V potention. Just mounting the case will short out your 5V power supply. The RF shield for the tuner module will also be at a 5V level. Connect an antenna that isn't completely isolated and you also short out your 5V power supply. Not worth the risk in my opinion.

**silencery** · 01-22-2005, 09:14 PM

How to change voltage coming out of your molex: http://www.silentpcreview.com/Sectio...e-artid-6.html

Gotta pay attention to strohmrs advice though, might not work for your situation. You can try that method w/o having to spend money on an adapter though.