I am soon to be getting a people carrier (I know this is a kit car forum, but you seem to be a great source of all info). The car will be used mainly for my wife and she hates big cars, so I am thinking about getting a reverse sensor kit.

The way they operate is to switch the rear sensors on when reverse light has power. Seems sensible enough, but some kits have front sensors too. I asked a seller on e-bay how the front ones came on, his reponse was they are switched on by the brake light feed.

Now that seems odd to me, so everytime you brake the front sensors come on.

What I was thinking of doing was fitting fronts and rears, but having them connected to a dash mounted switch, so when you want to use the sensors, just turn them on, when not needed, turn them off.

But then I thought it must be possible to just have a push button to turn them on and have a delay timer (say 2 minutes) to then automatically turn them off.

Sensible idea? or not?

So, anyone point me in the direction of a suitable circuit diagram?

Or has anyone got experience of these sensor kits and can offer any other advice......

Apart from, learn to reverse properly

Thanks in advance for your help,
Steve

I would have thought they would be permanently live myself run directly from the ignition. Wouldnt like to rely on remembering to switch them on before trusting them to stop me (or more importantly the missus) driving into the car in front.

mine are on all the time...

I would have thought the reversing ones are activated by power in the reversing light circuit, otherwise you'd get the warning beeps when the guy behind you at the lights is too close....
I don't know how you'd sort the front ones to be only on when appropriate (only when you're in 1st perhaps?)

quote:

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Originally posted by Paul TigerB6
Wouldnt like to rely on remembering to switch them on before trusting them to stop me (or more importantly the missus) driving into the car in front.

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seconding what ^^^ says.

If you need a parking sensor on the front then you shouldn't be driving.

What about one on the roof when you need to drive under extra low bridges or car park barrirrs?

Parking sensors are a really useful aid.

Get that last bit... AID, they are not going to be used purely alone to park, my wife is used to diving small cars and she test drove a people carrier at the weekend and she could not tell easily where the front and rear of the car were.

She has never hit any stationary objects while parking. Neither have I, well, OK once in a works van , but a parking sensor would have been ideal then. So thats why I'm thinking about getting one.

Surely because I want to improve the safety of our driving standard then thats a good thing?

How do I disconnect the airbag and ABS, as I will not be using these as my eyes will tell me to avoid all ice patches and accidents

EDIT: Martyn, thanks for the info on the 555, i'll have a look and see if i can figure it out.

[Edited on 27/3/08 by balidey]

I agree, parking sensors are very worth having for anything bigger than a supermini, I believe the best thing for the front is for them to be always on or linked to first gear?


Just had a thought - the only slightly worrying thing with having the front sensors powered on permanently is that there's a possibility that their annoying beeping will be the last thing you'll ever hear...

[Edited on 27/3/08 by jlparsons]

Oh don't take my rant too seriously, it was more aimed at the way I read Paul's post implying utter reliance and that if the sensor was turned off you *would* hit something

New-ish Audi's have the front sensors on all the time until you push a button to turn them off, and my god it's annoying in a traffic jam. Unless you want to turn into a homicidal maniac the first time you hit rush hour you really need to be able to shut the thing up.

Nothing been taken seriously guys

I'd rather get sensors fitted as soon as we get the car than after a few weeks when the bumpers are scuffed to hell

I like the idea of a switched feed, then you only put them on when we need them on.

Peugeot 406 & 806 turbo diesels have glow plugs that operate for 2 minutes AFTER the warning light has gone out. This might be a starting point for getting your timer.

A 555 monostable driving a relay will do the trick. 555's will drive quite a hefty current to so unless you're driving a humungous relay you won't need a transistor either.

I think you'll find this would do nicely

http://www.eleinmec.com/article.asp?4

Even gives the cost of the circuit (£3.91)

I found that site earlier today too. Looks like it will do the job. I even checked the current drain on the sensors and its under the 200mA so I won't even need a relay.

I'll have a chat with the missus and see what she thinks.

hmm, probably said before, permanent live from the key switch, and you shouldn't hear a peep out of them until you're parking. unless you have a thing for tailgating, in which case you deserve them shouting at you

Advise at least 4 sensors on the rear --- if you get a 6 sensor kit fit two of them at a different level so they cover low car park barriers when up close.
Make sure you get a kit that includes the exact size hole saw.

With rear sensors for psychological reason fit the bleeper in the rear. Fancy displays don't help much except while you are getting used to judging distances from the bleeper.

If you fit front sensors it might be more sensible to fit a distance display type and switch off/discconnect the bleeper.
http://parkingsensors.co.uk/?source=gpsv&gclid=CMjk7IHDrZICFQ8gQgod3w2dRw
Shop around on ebay for prices

[Edited on 27/3/08 by britishtrident]

[Edited on 27/3/08 by britishtrident]

quote:

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Originally posted by blakep82
hmm, probably said before, permanent live from the key switch, and you shouldn't hear a peep out of them until you're parking. unless you have a thing for tailgating, in which case you deserve them shouting at you

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Just been checking out the details in the website you just posted. Seems some kits advise fitting a switch for the front sensors so you can turn them off.

But they work on the brake switch, so I guess they must have a timer system built into the proper kits anyway.