Car electrics again..

[piman]

Hello Shenion,

I didn't understand that you were talking panel meters, as the comparison was digital to analogue which made me assume multi meters?

Certainly digitals are tough but not all analogues are that fragile?

Alec

 

[shenion]

Analog panel meters can be tough.

The early built in ones were a bimetal strip wrapped with nichrome wire. Voltage heated the wire and the expansion of the bimetal strip moved the needle. Would vary 10-20% over ambient temperature and slow to respond to changes. I think my jeep has one. Has 10V,12V and 14V marks and nothing in between These were tough as the needle was driven by a considerable force.

Many factory analog meters are 2-phase AC. Can be very accurate but requires a computer to run them. Also they stay put when power is turned off.

I imagine there are some accurate analog VM's for cars. Not cheap though. Things like temp guages and oil guages don't need real accuracy. These are usually on the order of 5% or worse.

5% may sound ok, but if your bat is near 13v and it reads 13.8 you might think it is charging That 0.8v is 6%. You will know later as it would keep dropping

 

[oddball90]

Back to the orginal thread, why don't you just mate a compressor to the engine via an electric clutch drive(air con pump) should give you the volume of air you require.

 

[Davie]

Please tell me I didn't see someone suggest NOT running a fuse?

Maybe you'd get away with it if the second battery was under the bonnet with the engine and alternator, but if you are considering running a big fat cable through a bulkhead, put a fuse in line for safety sake. Might be expensive, but better than a big bonfire. And if you wanna be really flash with it, try getting some 12v circuit breakers.

200 amps will make a hell of a mess of car bodywork.

 

[shenion]

200 amps will make a hell of a mess of car bodywork.

Adding a 200A fuse will not make a big difference for most shorts.

Fusing the main line will cause power drops and many are unreliable.

 

[cobminor]

Put an ANL fuse in it. I got one from a marine supplier for about £12 complete with holder.

 

[cobminor]

Oddball, using an air con pump is not that easy, they are lubricated by the oil in the refridgerant, so you are running the pump without oil. You need to inject oil in and collect it as the air comes out of the pump. The latter is not so easy. Old USA York compressors and some Denso ones have their own oil system but I have never seen either.

 

[Gasman]

Surely once the suspension is inflated and the tanks are full, provided they are not consuming or venting pressure all of the time I don't really understand the need for such a large setup anyway.

Heavy old Range rovers with air have a 12v compressor not much larger then a pint glass.

A rotary aircon compressor would not work due to lubrication issues but you could source a baby piston compressor to be belt driven with an electric clutch.

Yea OK, loads of money already spent on the original idea .

 

[Drains]

Please tell me I didn't see someone suggest NOT running a fuse?

200 amps will make a hell of a mess of car bodywork.

Davie, is there a fuse between your battery and your starter motor? No.
Is there a fuse between your alternator and your battery? No. (well maybe, just maybe a fusable link)

Is there a fuse for everything else? Yes.

 

[migmag]

Surely once the suspension is inflated and the tanks are full, provided they are not consuming or venting pressure all of the time I don't really understand the need for such a large setup anyway.

Heavy old Range rovers with air have a 12v compressor not much larger then a pint glass.

A rotary aircon compressor would not work due to lubrication issues but you could source a baby piston compressor to be belt driven with an electric clutch.

Yea OK, loads of money already spent on the original idea .

I have a YORK pump fitted but as said even with a york you get oil in your sysrem,Not good for valves and certainly not good for the bags.....

As for the shier volume of air required I need it to do this.

http://uk.youtube.com/watch?v=DITcCT7wM78&mode=related&search=

http://youtube.com/watch?v=c8lJXhJLNR8

No not that fast but you get the picture.
A range rover uses eighth inch line and probably 100psi,
I'm using 1/2 inch line and 200psi..
The more air the more playtime.

I'm working on a small hgv air brake comp as it pumps dry air but I need a clutch adapter machining up............Any volunteers??

 

[migmag]

Much easier if you have a look on here.........

http://www.layitlow.com/forums/index.php?showforum=17

 

[Gasman]

Cunning plan?!! ditch the compressors, days of labor & electrical nightmares and strap a cylinder or two of OFN in the boot, plumb into a regulator, no nasty oil or moisture in your system, job done

 

[migmag]

I hear ya gasman but one bottle only lasts so long and if switch happy would only last a weekend..........

In an ideal world a bottle of helium in a closed gas recycle system using a couple of comps to boost the pressure.............

Have a reed through on the....... layitlow forums its all been tried before
My first "bagged" car...