electrical question

[ICP]

Ok, I'm trying to figure out how many watts a certain battery puts out. I think I found the conversion, but I want to be sure I've got the right thing.


I know watts=amps X volts

So If I have a 9v 150maH battery.


150ma = .15 watts/volt ???

so then this battery would put out 1.35 watts ???????

Is this correct, or does someone know the right way (if it's not correct)

Thanx

[txaggie08]

oih hell i think thats right.....illd get you a better answer but my friend whos a EE is asleep

[ICP]

I hope so, cause if it's right, I believe I found a battery that will supply enough power for the electromagnetic valved gun, I'm working on.

[Maggot6]

Are you in highschool? Any science teacher would know..

[deadeye9]

Correct.
It will put out up to 1.35W.

[ICP]

Nope not in high school (25 and workin like a dog). But I did some research and found the answer this morning. The boss has a old fundamentals of electronics book from college.

thanx for the answer the though, now to find what I need locally.

[SlartyBartFast]

Uhm...

The maH rating is the capacity. Not the maximum current. It means if you pull 150ma from the battery, it'll last 1hr.

What you need is the voltage drop versus current draw caracteristics of the battery.

Think of the maH or AH rating as the size of the tank and the maxium current rating as the size of the pipe out of the tank (or the capacity of the fuel pump).

So, a 9v 150maH COULD power a 1.35W component (or actually, one that draws 150ma at 9V) for one hour. But what is the current draw and voltage required by your circuit?

[ICP]

I'll try to explain what I want.

I've got an electromagnet that runs off 9V. The strength of the magnet depends on the wattage input (that's the only specs listed for it). I found a batter that is 9v 1200maH. Wich comes out to about 10.8 watts (so this means that it will only have that power for an hour of continous use??? ). I want to try to push ( for now as an estimate) 3 watts into the EM. I'm not even going to try to make the board myself, but want an idea of what is needed. If I can just "choke" the wattage down with something for now (without a board) I would like to do that to make sure everything works like I think it does.

Here is the link to the electromagnet, in case I'm missing some important information.

http://www.solenoidcity.com/electromagnet/e-66-75p1.htm

and then at the bottom left you can also click the more information box, to see more.

This is where my problem lies. I have very little to no knowledge of electronics and I am kind of learning as I go. (i know, not the best way to do it).

Thanx for any help.

[SlartyBartFast]

I want to try to push ( for now as an estimate) 3 watts into the EM.

You can't "push watts". Circuits draw power based on the voltage and the circuit's resistance.

The resistence of the solenoid coil has to be given or, if the solenoid spec gives voltage and wattage, you can calculate the resistance.

If the solenoid is a 9V solenoid, the rated wattage will simply be the wattage (and current draw) on a 9V source.

I don't know what "approximate ampere turns" means on that spec sheet. But it seems to me that the solenoid in question is provided in a form that you decide which wire to wrap the core with and how many turns. That would be what the table is for indicating the variable resistance and required voltage.

But now I'm guessing.

[ICP]

Now i'm confused. lol

There are two configuration I can go with.

1. 4.7 ohms and 6.9v

2 8.4 ohms and 9.2v

both with the 650 ampere turns. (1/10 duty cycle, max on time 30sec)


But ya, it seems your right, I can choose witch one I want. What is the relation of ohms, volts and watts. How is the resistance going to affect the power that I want? Oh damn, guess I go read some more. Thanks for the help. Very appreciated.