Why 18v in the Emag?

[mrhooie]

watching the emag video tonight, we were wondering why an 18V battery in the emag?

What is it regulated down to?

Just wondering why, to see if something else could be used at sometime as a battery (to make the front pack a different size)

thanks

[BlueMagRT]

it is 18v because as the great Tom Kaye put it: 9v's suck.

the e-mag has a large battery to power a larger solenoid. this reduces heating of the solenoid which gives better performace, more shots percharge, and easier pull. It is also a more reliable option. i believe tom said you could shoot the e-mag at full auto and not over heat the solenoid until the battery is almost dead.

[mrhooie]

Ok, my next question would then be, what does the Solenoid tun at? The 18v is obviously regulated down to a smaller voltage.

Now - was the original emag the same one that I can buy now (as far as internals?)

[Shaft]

In the same tradition of 42v systems in automotive applications (yet to be realized).
18v was chosen for lower current. Ohm's law fun.

[mrhooie]

Shaft - I kinda figured your post was in jest, but if it wasn't, I realize that the 18v isn't being used at 18v. WHy? because you'd never get 20,000 shots on one charge if the solenoid was 18v (or even 12v for that matter)

[Butterfingers]

Cause when battaries are used they drop in voltage.

The E-mag actually needs all that juice. I belive it ceases to function at about 14volts.

[AGD]

There were several reasons to go with 18v. First and foremost was reliablility. The more current you put through a solenoid the more it heats up. The more it heats the less it pulls. If it gets too hot it stops firing the marker. A marker that doesn't shoot because "you shot it too much" is completely unacceptable. We wanted a design that could shoot ALL the time without problems.

We might have been able to use 12v but then you couldn't step up the voltage to run your rev. We forsee the time when the whole marker is run off one battery. It really doesn't make sense to have different batteries all over the product. Do you see anything else with multiple sets of batteries? Wouldn't it be stupid to by a tape deck for your car that needed batteries?

18v gives the right flexibilty to run anything in the foreseable future. You can always regulate down, it is very expensive to boost voltage up.

Just thinking ahead for your benefit,

AGD

[Dubstar112]

AGD always plans ahead, kinda like them extra holes in the old rt..

[mrhooie]

Thanks Tom - we were just curious as to why?, but that helps...

So what does the solenoid run at? I was curious..why? For my own reasons (like getting the size of the battery pack down)

Just some thoughts...But I really like the idea of getting the whole marker and 'gadgets' to run off the battery.

(where are you going to fit the alternator )

[mrhooie]

Ah ----------the only thing I forgot

Were you wanting to put a larger capacity rechargable battery pack in it originally?

Originally posted by AGD -
The more current you put through a solenoid the more it heats up. The more it heats the less it pulls. If it gets too hot it stops firing the marker

[momags!]

Tom......I'd be more than happy to sell you my design for single battery utilization!
It comes with all the gadgets like a variable resistor and single power switch for the entire system! And it all fits in the warp battery compartment. Tried and true. Give your engineers a break....I need the money!

[momags!]

Actually, I would be thrilled with just an endorsement from AGD! Want a free unit to look over and try?!

[Shaft]

Originally posted by mrhooie
Shaft - I kinda figured your post was in jest, but if it wasn't, I realize that the 18v isn't being used at 18v. WHy? because you'd never get 20,000 shots on one charge if the solenoid was 18v (or even 12v for that matter)

Um... no, I was serious.
Out of curiosity, explain your theory.

[mrhooie]

Well, with Tom saying the 18v was chosen so that other items could be run off one battery - well that explains it with there.

You have an 18v battery that supplies x current.

If you regulate the current down to a device that uses less, the battery lasts longer (ie. 20,000shots off one charge)

easy as that.

[Shaft]

Oh. Regulators don't typically work in a way to conserve power. In fact, they use some. Switching regs and some LDO's can be quite efficient though.

Now supplying 18v straight to a load doesn't necessarily mean that the load will consume all the current in one zap (or two, three etc.). It will depend on what the load is and how much the battery can supply.

Now if you want to regulate current, you don't have to regulate the voltage. Just control the load.

Using higher voltage will allow lower current. Which was one of Tom's points about 18v and mine about 42v systems. The current causes heat requires bigger conductors - etc. Jack up the voltage, lower the current and you can maintain a large resistive load without creating a lot of heat.