Parallel circuits and lowing voltage.

[highny]

Hey there everyone!

I'm planning on modifying my stupid G18c AEP so it could take an external battery(woohoo). Just to keep myself busy and from spending more money on new shiny guns!..

Here is what I want to do.

I want to mod the G18C so it could take an external battery.

Also with the same battery, I want to be able to hook up a flashlight to it as well but the flashlight only takes 2 3volt(so 6v total) battery. So I came up with this.

I want to use a 8.4v battery and connect it to the AEP(I only use semi anyways, so no big worries). With a parallel circuits I somehow lower the voltage to 6volt.

My question is, how can I lower the voltage in a parallel circuits? Do I use resisters? Or is there a different approach?

If this is possible, would it be alright to lower another parallel down to 1.5v(for the red dot).

Thanks!

[zone 69]

Have you seen this.? http://shop.ehobbyasia.com/tokyo-mar...pro-light.html

[teck]

Modding a AEP for an external battery is easy enough, but where are you putting the battery? You will have to use resistors in parallel and make sure the voltage drop is is high enough for the light not to get overloaded. Doing this will increase the amperage, thus draining the battery faster. Yes adding a red dot is also possible. That would be a sick clock =)

[Kos-Mos]

You could also use a small LiPo in the place of the original battery.

You can easily fit a 900mAh 7.4v LiPo in there with a Dean's micro 2 connector. If won't damage your gun, gives you higer ROF and capacity.

In all seriousness, it is possible to wire your single 8.4v battery to drive everything. If you use resistors, you will be generating a LOT of heat for nothing, and in the end you would have to use a large battery (more than 2000mAh) to see a difference. Plus all the wires running everywhere.

If you use an electronic switching circuit, you will have to find a place to fit a little board about 1" square, that is considering you use surface-mounted components.

At that point, with the flashlight and RDS, it would be easier to sell your AEP and buy a MP5K instead... Weight will be quite the same but at least it shoots good.

[teck]

I would love a project like that!...or an independently powered RDS and light
He would need a custom PCB board too

[highny]

Originally Posted by zone 69

Have you seen this.? http://shop.ehobbyasia.com/tokyo-mar...pro-light.html

The main point is "do it yourself", second I want to keep the cost as low as possible. Wires, connectors, soldering is easy, so is working with simple circuits. So Why spend the $100 on something nice and shiny when I could practice the old and learn the new?

Originally Posted by teck

Modding a AEP for an external battery is easy enough, but where are you putting the battery?

I'm planning on putting it on top of a rail system, from the looks of it, I should still have about 2 inch left on the end of the rail for the red dot.

Originally Posted by teck

Doing this will increase the amperage, thus draining the battery faster.

I have three 8.4 battery powering mini fans around my work station.... So I don't think battery is something I worry about in game.

Originally Posted by Kos-Mos

it would be easier to sell your AEP and buy a MP5K instead... Weight will be quite the same but at least it shoots good.

I would love to get an MP5k... But considering the price of those VS my AEP... I'll still have to toss in $100-200 just to top it all off.



Thanks for all your reply! Any idea on what type of resister I should use? I don't use resisters in any of my project, but I do know what they do and how to use them.

[mcguyver]

Originally Posted by highny

Any idea on what type of resister I should use? I don't use resisters in any of my project, but I do know what they do and how to use them.

The resistor you need depends on your load. You need to know what resistance your bulb is, then back-calculate your resistor size based on your required voltage drop.

Or you could also use a voltage regulator, but you need the load of the bulb for that as well.

[highny]

Originally Posted by mcguyver

The resistor you need depends on your load. You need to know what resistance your bulb is, then back-calculate your resistor size based on your required voltage drop.

Or you could also use a voltage regulator, but you need the load of the bulb for that as well.

How do find out the resistance of my bulb?

PS: I do have an old multimeter, but I don't remember which setting is for resistors.

[teck]

you said that the light was 6 volts right? and the battery is 8.4 volts, you know the voltage drop, 2.4 volts. what sizes of resistors do you have? do you know how to read a resistor?

[ThunderCactus]

+1 on the lipo idea actually, you just have to be careful not to over-discharge the battery. But even if you do, it only causes problems when you charge it back up

[highny]

I on a resistor, each color means something, just got to find that darn chart.

I also was told that adding a 2.4v FLED in the circuits with the flashlight will work. Can't remember for sure those. Does the FLED let what's left of the voltage through or does it let what it holds through?

Also, where is the safest way to put a resistor since it will get pretty warm if I leave the flashlight on(which most likely not more than 30sec)? Should I isolate it or can I electical tape it to the battery?

[ThunderCactus]

Try not using any electrical tape at all on this project

[teck]

you might have to use a 4 or 5 watt resistor.
I got the code HERE