Fuses for different voltages

H.O.T.A.S.

Hey guys, just looking for a bit of advise for this one. What fuse do you reckomend for a 9.6v batt? TM use a 15A fuse on their AEG's but Classic Army use a 20A. Just wondering what fuse I need to get if I'm using a 9.6v battery. Cheers lads

H.O.T.A.S.

kdouglas

i've used a 9.6v battery in a stock aeg without upgrading the fuse and it worked no problem, even with a systema turbo motor, which would pull more current then a normal motor, and the 15a fuse managed fine, im not sure what kind of current an aeg pulls under normal operation, so it's hard to say, but i'd have a couple of 15a and 20a fuses to hand just in case

someone who knows more about electronics can answer this better tbh, im a bit rusty since the LC, but i did find this calculator

Edit: and a bit more info here

H.O.T.A.S.

Cheers Kdouglas, so in your opinion is it safer to err on the side of caution and get a 20A or stick with a 15A? Using 8.4v and a 15A fuse as a base line means that the average AEG has a resistance of 0.56Ω. Therefore an AEG with a 9.6v battery would need a 17A fuse.

kdouglas

that's assuming the 15a fuse is actually what is needed, i just checked my m249 and there is a 10A fuse in it, i ran that all day last saturday with a 9.6v 1500mah battery in it and the fuse is fine, although it did come with a 25a fuse installed, i blew that when i was messing about with wiring and such, cant remember now exactly what i did, but it wasnt anything that would be considered normal operation of the aeg

Fiach Dubh

I'd say the selected fuse amp's is dependent on the make of AEG, assuming that is that the AEG maker has performed tests with the gearbox before marketing the gun. I've just finished repairs on my VFC AK after one of the bushings shattered the fuse blew, this was because I held the trigger down for a couple of seconds leaving the cicuit complete for too long. The origional fuse was a 25 amp 32v automotive, I wasn't going to change VFC's choice so I installed a new 25 amp automotive (a lamped version) very handy piece of kit, the lamp glows when the fuse blows.

The choice of a 25 amp is interesting because VFC make claim the AK will run with an 8.4v pack and some people have been running them at that power. I however bought an 8.4v stick when I got the AK and it couldn't pull the spring through I had to switch to an Intelect 9.6v. When I contacted GB tech about that issue one of the engineers told me to run it with a 9.6v stock. Sorry, rambled a bit there, just interesting, I've seen a number of clones running with 9.6v's power and a 15 amp fuse and seem to have no trouble.

I'd say for 9.6v 20 amp's should be fine, 25 amps will make sure.

Wossack

H.O.T.A.S. wrote: »

Cheers Kdouglas, so in your opinion is it safer to err on the side of caution and get a 20A or stick with a 15A?

erring on the side of caution would mean using the lower rated fuse

Harekin

Fiach Dubh wrote: »

I'd say for 9.6v 20 amp's should be fine, 25 amps will make sure.

Thats not how fuses work...the lower ampage of the fuse the safer it is.

Fiach Dubh

I know very well how fuses work. To low an ampage and they blow outright, to high and they'll allow overcurrent.

hoplite

Lads where is the best place to get the fuses preferably local. Maplin?

Fiach Dubh

Yep, Maplin have fuses of all shapes and sizes

H.O.T.A.S.

Maplin only have the 10A micro glass fuses so they wont fit your AEG. Might want to try Peats

kdouglas

your local motor factors should do them, i got some in rathgar motor factors a while back, but they only had 25A fuses at the time

Fiach Dubh

Hmmm Maplin must be low on stock then. They can order any fuse you want though if you have trouble finding them elsewhere. Just go onto the Maplin UK website, find the stock number of the fuse you need, ring your local maplin and ask them to order some. They should get them in a few days.

kdouglas

you can also order direct from radionics.ie

Boston

Have to say I'd recommend radionics for any electrical part over the likes of peats or maplins.

kinkstr

Ive blown the fuse in my dboys m4, and decided to try a fuse from a wall socket which is 13a. It turns the motor but is the right amp or do i need something different for an 8.4 volt battery?

Masada

I think the fuse in one of these is a 25amp,

EDIT, just took mine out to check for ya and i smashed it.,lol

kinkstr

Cheers Vtec, when i put the gun back together i tried it again with the 13Amp fuse and all that happened was that the battery got quite hot in a matter of a few seconds and it wouldnt turn the motor, i presume this is down to the fuse and not something else?

kdouglas

if the fuse is blown then nothing should happen at all, the battery shouldn't be getting hot, it sounds like you could have a jammed gearbox.
if the motor isn't turning (but trying to) the battery will heat up

kinkstr

It was the new 13amp fuse that made the battery hot not the one that came with the m4, nothing at all happened when i hooked up the battery to the old fuse.

kdouglas

i'm confused, you said:

kinkstr wrote:

Ive blown the fuse in my dboys m4, and decided to try a fuse from a wall socket which is 13a. It turns the motor but is the right amp or do i need something different for an 8.4 volt battery?

kinkstr wrote:

Cheers Vtec, when i put the gun back together i tried it again with the 13Amp fuse and all that happened was that the battery got quite hot in a matter of a few seconds and it wouldnt turn the motor, i presume this is down to the fuse and not something else?

so is it turning or not turning? when you put the gun back together, what had you taken apart? did you open the gearbox at all or is the only thing you've touched the fuse? what caused the fuse to blow in the first place?

kinkstr

Sorry, the part i didnt mention:)
when i tested the 13Amp fuse the motor wasnt in the gun, it was in my hand, when i put the gun back together and tried it again is when the batter got hot. Ive had the gearbox open before after it jammed midway through a skirmish, opened it up untensed the gears and it worked again, then a few days later it jammed again, and after i had thought i fixed it that time the fuse blew(i think)
There is no sound comming from the motor either, the other times tjhe gearbox was jammed i could hear it trying to turn.

Masada

Best thing to do is put a multimeter on the fuse so you know if its defo blown, (or if its a glass one you'll know by looking at it,. the 13 will blow once theres load on the motor i reckon., the gears sounds more like they need to be properly shimed or theres damage on them.,

EDIT: i mssed a coule of posts there, it looks like your fuse is ok but i cant see a 13a lasting in it, id say its the gears alright.,

kinkstr

Yea its the glass one, the strip in the fuse has gone very discoloured and looks fooked from what i can tell.

Masada

that would have just happened form the heat, if its not broken then it should be fine., try taking off the pistol grip and pushing the gears with a small flat head,. theres 2 screws in the bottom of the grip, then remove the motor and then theres 2 more inside the handle and then it'll come off. when it does you should be able to turn the gears through the socket where the motor goes in., if its tight you should check that al the shims are there and if they are, make sure that there not pressing the gears against eachother too strongly. it should be just enough to make sure theres no wobble but not too tight.,

kinkstr

Yep it is the gearbox, something is not right in there but i havent a clue what it is:eek:
Sorry for goin off topic on the whole fuse thing.