Electrical Saftey/Transformer project

[Reloadron]

Yes, especially under no load conditions.

Ron

[Zambini]

ok.

I didnt have any more 9v batteries so I had to use 8 x AA to make 12v which is generating a TON of heat (12v->5v makes the voltage regulator go to 110°C from room temp, lol)


But it works just as well. Only costs about 2x as much cuz 8 AA costs more.

=P thanks

[Reloadron]

Originally Posted by Zambini

ok.

I didnt have any more 9v batteries so I had to use 8 x AA to make 12v which is generating a TON of heat (12v->5v makes the voltage regulator go to 110°C from room temp, lol)


But it works just as well. Only costs about 2x as much cuz 8 AA costs more.

=P thanks

You lost me here somewhere? We went from this:

This is for another phys project, but when a 9v battery reads 7.14 volts, it's considered a dead battery, right?

To a post with a voltage regulator and heat? The VR should not be generating that much heat. Unless it is under a pretty good load condition. Now if you are feeding a 5 volt regulator like for example a LM 7805 family and it is producing that much heat your batteries may be short lived.

Tell me what you are doing and I will be more than happy to provide a drawing or any help I can.

Ron

[Zambini]

Yea I'm using a 7805, but I didnt have any more 9v batteries so I put an 8 x AA battery clip into it instead. I should have used 4x AA battery but for some reason I didnt.
Anyway, 12v being "regulated" into 5v generated quite a bit of heat as you can see. :)

My project is basically this:
how-to: 'usb battery' v2 - Hack a Day
less the case for it. I just have it wired to a project board and some cardstock.

[Reloadron]

Originally Posted by Zambini

Yea I'm using a 7805, but I didnt have any more 9v batteries so I put an 8 x AA battery clip into it instead. I should have used 4x AA battery but for some reason I didnt.
Anyway, 12v being "regulated" into 5v generated quite a bit of heat as you can see. :)

My project is basically this:
how-to: 'usb battery' v2 - Hack a Day
less the case for it. I just have it wired to a project board and some cardstock.

Nice little project as well as practicle. Yeah, the thing to remember, and they mention it, is the excess voltage is dissapated as heat. Therefore using 4 batteries (6 Volts) would have produces much less heat. Hey, long as it works. If you have anything around that would work you could make a small heat sink for the 7805.

Ron

[Lead Head]

Originally Posted by Zambini

Yea I'm using a 7805, but I didnt have any more 9v batteries so I put an 8 x AA battery clip into it instead. I should have used 4x AA battery but for some reason I didnt.
Anyway, 12v being "regulated" into 5v generated quite a bit of heat as you can see. :)

My project is basically this:
how-to: 'usb battery' v2 - Hack a Day
less the case for it. I just have it wired to a project board and some cardstock.

How small does it have to be? You can use 4x AAs, or even one of those bigger lantern batteries.

[Zambini]

Yea I know, I have a 4x AA adapter. for some reason I didn't use it tho =/