12V battery problem

[mycrobug]

I've built a pit box that holds my tools and extra parts & tires fer racing... In the front i cut out a hole and mounted a charger pannel to charge what ever batteries i may need to charge... That works really well...

Heres the problem........................

I want to run another circuit off the same battery and that needs only 1.5v from the 12v battery... This circuit is going to be wire going from the 12v battery to a jack... This jack will allow me to use a use a batteryless glow starter yhat i can plug into the jack when i need it... How do i get the 1.5 volts i need using the 12v battery ? What is the propper amps for a turbo glow plug ?

The facts...................................

Sealed rechargable 12V 7amp battery
Need to step voltage down to 1.5V
Charger pannel input is 12V

 

[olds97_lss]

I saw your other thread about this. Only one thread is needed.

You could probably just use this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXTVD6&P=7

 

[moe7404]

lm317 voltage reg
just google it. i have built lots of these, they are easy, but its NOT a battery charger. i have never built a charging circuit , that takes a different circuit. if you are driving a glow plug you will need to know how much amps it draws. but there is lots of sites that show you how to do electronics. if you need help just e-mail me, [email protected]

 

[olds97_lss]

if you are driving a glow plug you will need to know how much amps it draws.

Might benefit others to know how as well. I figured there would be a 1.5V regulator out there, I just didn't know what the draw is of a GP considering it's more or less a dead short. It can't be a low draw... which may require a decent regulator to run it without overheating/burning up.

Looking at his post, he intends on driving the actual glow plug with the jack. Not using it as a charger for the heater.

 

[moe7404]

ok olds you hooked me. now i have to rig up a way to check amp draw on a glow plug. ill bet the different heat ranges will draw diff amps. so now i have charge up a bunch of 1.5 bats. this might take a day or two. lets see clips, wire, vom,,,,,

 

[mycrobug]

Thats exactly what I'm wanting to do, drive the actual glow plug with the jack... what i have is this, only mine has the male plug ends on the wire instead of the clips... http://www.hobbico.com/fieldequip/hcap2502.html model HCAP2502

 

[olds97_lss]

Geez, for $20, just get the whole panel:
http://www3.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=HCAP0302&sourceid=mozilla-search

Or it's little brother for $18:
http://www3.towerhobbies.com/cgi-bin/wti0095p?FVPROFIL=++&FVSEARCH=HCAP0301+&search=Go

Both charge a glow heater and drive a glow plug directly with an adjustable output level.

Found a cheaper smaller one:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHCA1&P=7

 

[moe7404]

glow plug amps

ok here it is
o.s. 8 1.0 amps fully charged NMH
lc3 1.1 amps " " "
o.s. A5 1.1 amps " " "

 

[olds97_lss]

LC3 is hot and A5 is cold. Not much difference between hot and cold, who knew!

 

[moe7404]

yep i thought the diff would be at least .5 amp. heres a LM317 calculator.

http://www.electronics-lab.com/articles/LM317/

 

[moe7404]

i looked at the data sheet for a LM 317. it will sink 1.5 amps even with out a heat sink. that should handel any glow plug. to be on the safe side a heat sink will give you extra protection.

 

[moe7404]

iam getting the parts together so you dont use any small batterys for the starter or glow plug., you use the battery in your street truck. i allready use my street truck battery for starting my t-maxx. if i can get all the right parts iam thinking of wrighting up an instruction set so others can do it to. what think?

 

[olds97_lss]

I think it's a novel idea to have something, but with the 12V chargers being relatively cheap or one of those power panels being pretty cheap, I'd go that route before I'd make something. Less hassle.

I can appreciate the effort it takes to make one though. I'd probably do it just to say I did, but then never really use it.

 

[moe7404]

"Less hassle.?" in the long run less hassle, more hassle in the short run. but i dont have to worry about a battrey going dead, before it should. what if you are having trouble starting your nitro? your 7.2 battrey will go down fast. but using a street truck bat, you only worry about over heating the nitro starter motor. i still have more parts to round up, ie radio shack, and an electronic shop called lloyds. i have done the math to get 1.56, 1.72, 2.09, 2.29 volts for the glow plug from the LM 317.

 

[olds97_lss]

I was only saying that making one is a bit of a hassle considering you can buy a purpose built device to do exactly what you want. The purpose built ones are also adjustable. I'm sure you can make one that is as well...

 

[moe7404]

iam not sure i can build one that is better, but it will be MINE. i bought some more parts at radio shack today. they have a double wire 18 ga one wire is red one is black. the 18 ga will handle as much as 6 amps at 25 ft. glow plugs draw 1.1 amps the starter draws 2 amps, so we are ok at 25 ft. iam having a lot of trouble with the supercharger fit up. i think if i shorten one throttle link it will work. i wount be able to work on it till sunday, iam going to motorcycle drags sat.

 

[moe7404]

du-bro has a kwik-klip ex-long. cat. no 338 upc 11859-00338 fits std glo-plugs $9.99. it doesn't have gader clips, but that doesn't matter cause we are wiring it hard to the starter wand.