Getting 12 volt from 48 volt supply?

[Harry Bloomfield]

How do you power your 45A one?

Very carefully

 

[JohnW2]

Very carefully

I certainly would - if I dared to 'power it' at all

Kind Regards, John

 

[DetlefSchmitz]

Floating ground, in the middle?

Why does a linear regulator have a floating ground?

 

[SUNRAY]

Not come across any with that sort of demand on 12v, the only 12v ones I have seen plug into the ciggy lighter socket.

This is what I have, https://www.jgs4x4.co.uk/t-max-12v-air-compressor-heavy-duty-portable-tyre-inflator-adventurer/

The main reason I have it is to pump up Clark SCAM (self contained army mast) telescopic masts in about 1.5 - 2 minutes the ciggy lighter toys take 20-30 minutes and die

I agree, it only takes a minute with a hand pump. Out of curiosity, a few weeks ago I tried one of those bike pumps where you stand on the base and operate with two hands - to blow up a car tyre. It was perfectly doable.

Sounds like a track pump

Yes I have a couple and generally use one to check the cars tyres. They are every bit as good as a footpump as long as your back can cope.

 

[SUNRAY]

Good grief! My car one claims to be 6A (at 12V) and I think all the car ones are designed to be plugged into the ciggy socket, which is usually/often fused at 10A. How do you power your 45A one?

Kind Regards, John

Leisure battery or the circuit I've installed in the boot.

EDIT: The 'proper' compressor for the SCAM mast from Clark is a low pressure (25PSI) 2 cylinger V compressor belt driven by a 450W motor, either 12V or 240V versions. but it takes twice as long to inflate a mast. Not only that; it's about 4-6 times the size and ****ng heavy, definitely a 2 hand lift and for some a 2 man lift as opposed to carrying a T-Max in one hand and 80AH leisure battery in the other.

 

[JohnW2]

This is what I have, https://www.jgs4x4.co.uk/t-max-12v-air-compressor-heavy-duty-portable-tyre-inflator-adventurer/

I was going to ask you why on earth you wanted/needed anything like as powerful as that (>500W is a lot of power for something not being used primarily to generate heat), but you go on to explain ...

The main reason I have it is to pump up Clark SCAM (self contained army mast) telescopic masts in about 1.5 - 2 minutes the ciggy lighter toys take 20-30 minutes and die

Fair enough, but that's a very unusual requirement. For once-in-a-blue-moon pumping up of one car tyre, the "ciggie lighter toys" are perfectly adequate - and, I would assume, even more adequate for an "e-bike" tyre!

I'm still waiting for eric to tell me how much current his pump uses.

Kind Regards, John

 

[Harry Bloomfield]

Yes I have a couple and generally use one to check the cars tyres. They are every bit as good as a footpump as long as your back can cope.

That's the one, surprising quick to pump a tyre up - not that I needed to use it, I have a mains compressor in the garage

 

[SUNRAY]

I was going to ask you why on earth you wanted/needed anything like as powerful as that (>500W is a lot of power for something not being used primarily to generate heat), but you go on to explain ...

Fair enough, but that's a very unusual requirement. For once-in-a-blue-moon pumping up of one car tyre, the "ciggie lighter toys" are perfectly adequate - and, I would assume, even more adequate for an "e-bike" tyre!

I'm still waiting for eric to tell me how much current his pump uses.

Kind Regards, John

I have never owned a ciggy lighter powered inflator, I find the track pump from earlier or a foot pump is less hassle and quicker, For once-in-a-blue-moon pumping up of one car tyre I've not yet worked out why one would bother with an electric device. My T-Max is just inside the door at the end of the drive, as is a track pump and I automatically go for the track pump.

Ask the 4x4 guys what they use... the ciggy versions just don't cut the mustard with their tyres and some will not inflate from 0PSI as they require back pressure to operate the valves.

 

[SUNRAY]

Getting back to my comment, many of the ciggy lighter inflators are more than the 10A rating of the sockets and the usual size of fuse.

 

[JohnW2]

I have never owned a ciggy lighter powered inflator, I find the track pump from earlier or a foot pump is less hassle and quicker, For once-in-a-blue-moon pumping up of one car tyre I've not yet worked out why one would bother with an electric device.

I'll leave you to ask that of (or tell that to) my wife and daughters

Ask the 4x4 guys what they use...

If it were relevant, I might, but I'm not a "4x4 guy"

Kind Regards, John

 

[JohnW2]

Getting back to my comment, many of the ciggy lighter inflators are more than the 10A rating of the sockets and the usual size of fuse.

Maybe - but, as I said, mine claims to be 6A.

Kind Regards, John

 

[SUNRAY]

I'll leave you to ask that of (or tell that to) my wife and daughters

If it were relevant, I might, but I'm not a "4x4 guy"

Kind Regards, John

Well I'd say train your wife and daughters better, recently an elderly neighbour with mobility issues had his tyre pressure warning come up and knocked on the door forhelp. I wasn't home but 'er indoors grabbed the track pump and pumped his tyre. I see no reason for your females to be any different unless infirm/elderly etc.
I bet they wouldn't change a wheel either?

 

[SUNRAY]

Maybe - but, as I said, mine claims to be 6A.

Kind Regards, John

Yeah but have you measured it? My experience is they are sometimes higher than spec'd.

 

[JohnW2]

Yeah but have you measured it?

No, I haven't measured it. However, I have run it for quite long periods (for purposes other than pumping up a car tyre) from my car's ciggie socket without it having blown the fuse (which I now to be 10A).

My experience is they are sometimes higher than spec'd.

I obviously cannot argue with your experience.

Kind Regards, John

 

[ericmark]

Seeing @chivers67 post, and the CO2 inflater, that seems a better option.