12V car cig lighter adapters - safe?

Fuck all happened. Difference is I had the night heater in the truck instead of a heated window. A night heater is a bit of kit which has an electrode which heats up diesel and a fan to blow the resulting hot air into the cab. Works like central heating in the fact that you set a temperature and it comes on and off to maintain that.

A night heater draws more current than a window heater and the electrical noise from the fan far exceeds that of the window heater to the point where it can be seen as RF interference on a TV.

And my laptop still works.

So again, you're talking out of your arse.

Reply to
Conor
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I use my laptop in my lorry. Its exposed to far more electrical noise and far higher potential back EMF than you'd get in a car yet my lappy is working fine.

Reply to
Conor

Yeah, Eberspächer. Got one in my campervan. Brilliant things. Even during -6 nights I was almost too warm. and had to turn the themostat down.

Graham

Reply to
Graham

That's the jobbie. Only downside to them is getting them to fire up for=20 the first time after a summer being unused.

--=20 Conor

I only please one person per day. Today is not your day. Tomorrow isn't=20 looking good either. - Scott Adams

Reply to
Conor

Can you read ok Conor? 'Dont disconnect the battery with the laptop connected' is what was said. Tell you what, since theres no problem why dont you try it and prove it to us.

NT

Reply to
meow2222

If there's no problem why is the subject of 'load dump' and other transient overvoltages taken so seriously in the automotive electronics industry? Why are detailed specifications and standards written and a great deal of testing done? Why do the semiconductor manufacturers develop and make automotive-rated devices? Why does Google return over

7,000 hits for "automotive load dump" and nearly 84,000 for "load dump" most of them probably automotive-related?
Reply to
Andy Wade

Really all that you can deduce from that is that nothing bad happens in your environment. It doesn't give the data to say that it can never happen in other cases.

In my early engineering career, I designed electronics, control and communication systems that were often fitted into military vehicles of various types.

In general it was necessary to incorporate various filtering and protection into the DC supplies to the electronics, because of electrical spikes and noise from the vehicle systems. Primarily, this was to avoid damage to certain sensitive semiconductors in the equipment and did so successfully.

The far harder problem was dealing with the sensitivity of the radio receivers, that were working in the 2-30MHz range from being swamped by the general electrical noise.

For example, on a tank, when the turret was rotated, one could find sharp rising spikes of 600-800v on some of the wiring.

I suspect that in a typical domestic car and possibly even a commercial truck, the potential for problems is not as great and certainly electronics has been improved from the EMC perspective over the last decade. Nonetheless, the mechanisms for bad things to happen are certainly present in a motor vehicle.

Reply to
Andy Hall

Because if the elctronics inside the car failed at that point then a loose battery lead would write the car off. Which would be highly embarassing to have to explain on watchdog & have enormous liability issues for anything safety critical. & it's most likely to occur during initial startup & subsequent servicing, your laptop/pda etc. are orders of magnitude more likely to be stolen because they didn't fit laminated glass to the windows.

Reply to
Duncan Wood

"Dave Plowman (News)" gurgled happily, sounding much like they were saying:

Umm, cobblers. Many's the time I've come to remove a battery terminal only to find it's loose - and the thing's been running fine.

Reply to
Adrian

Ever heard of passengers? My lot are fiddling with countless gadgets while on the move. Some connected to car. The wife has been known to bid on ebay while we are travelling.

Graham

Reply to
Graham

Maybe for a new laptop, just in case the old one fries due to loose battery terminals :-) Oh, wait a minute, can't happen, the car would never start, not with a loose battery terminal - the electrons would go on strike..... what a load of twaddle people spout.

Julian.

Reply to
Julian

People have too much time on their hands. It's simply not a problem in practice.

Reply to
Dave Plowman (News)

That's a different matter from the topic under discussion.

So you don't use that wiring as pickup points for accessories.

What you're implying is that laptop makers who supply leads for car use are unaware of this?

Reply to
Dave Plowman (News)

Well if if it's capable of handling starter current it's not going to cause problems with the much lower currents from an alternator...

Reply to
Dave Plowman (News)

Of course. I'm simply making the point that conducted spikes in a vehicle do have the potential to cause damage.

In a tank you don't get a lot of choice.

I would say that that depends on the laptop maker and the accessory. If the accessory comes from the manufacturer of the laptop as an adaptor specifically for the purpose, then I would expect them to have done diligent engineering and if it breaks they get to own the problem. If I were to buy a cheap Chinese generic accessory, I would have little confidence in the engineering and not expect redress. Ergo, I would not buy cheap Chinese car accessory lead.

Reply to
Andy Hall

The car is rarely moving when the starter is being used.

Reply to
David Taylor

So you're saying you have a battery connector which rattles loose when the car is moving but magically tightens itself so the car can start?

Do you write for CSI?

Reply to
Dave Plowman (News)

Reply to
David Taylor

I currently am as I'm posting from that very laptop.

Reply to
Conor

It returns 31500 for "Andy Wade is a Wanker".

Reply to
Conor

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