mldpt
Well-Known Member
Hi I am looking for an external (outdoors) PIR that will control a 12 volt spot light, the PIR has to run off 12 volt also any ideas.
Regards Mike
Regards Mike
12 volt security light.
- Thread starter mldpt
- Start date
bdsweeting
Well-Known Member
Found this http://www.towsure.com/default.asp?t=92
for a bulkhead type light - any good?
for a bulkhead type light - any good?
William_H
Well-Known Member
Have a look at http://www.12volt.com.au they yhave alll sorts of 12v stuff... they specialise in mail order UK 43 pence for a oz dollar olewill
homer
Well-Known Member
Not very helpful, but I have been looking for exactly the same thing for some time - without success!
Various PIR switched alarms are available on ebay (usually said to be suitable for sheds and boats) but don't seem to be for exterior use. An LED based light would be preferred but the only ones I can find are hand held torches (which would need a fair bit of modification). I'll be interested to see if anyone else has found anything better!
Various PIR switched alarms are available on ebay (usually said to be suitable for sheds and boats) but don't seem to be for exterior use. An LED based light would be preferred but the only ones I can find are hand held torches (which would need a fair bit of modification). I'll be interested to see if anyone else has found anything better!
pvb
Well-Known Member
Check out CCTV suppliers...
The stand-alone external PIR detectors used with most CCTV systems work on 12v and are weatherproof. They vary quite a bit in terms of range (distance) and detection angle (horizontal), but can usually be masked off to suit the required detection area. The alarm state usually opens a NC contact so you'd need to put a relay between the PIR and the spotlight, and probably also a timer circuit so the light stays on for a chosen time. Bear in mind that the PIR and associated circuitry will draw a small current all the time.
The stand-alone external PIR detectors used with most CCTV systems work on 12v and are weatherproof. They vary quite a bit in terms of range (distance) and detection angle (horizontal), but can usually be masked off to suit the required detection area. The alarm state usually opens a NC contact so you'd need to put a relay between the PIR and the spotlight, and probably also a timer circuit so the light stays on for a chosen time. Bear in mind that the PIR and associated circuitry will draw a small current all the time.
mldpt
Well-Known Member
Re: Check out CCTV suppliers...
HI I assume that the PIR part of the security lights in DIY shops is 240v ac powered as is the lamp they are attached to, or is it possible tha the PIR runs off a transformer on 12 v dc and the lamp is switched through a relay. /forums/images/graemlins/confused.gif
HI I assume that the PIR part of the security lights in DIY shops is 240v ac powered as is the lamp they are attached to, or is it possible tha the PIR runs off a transformer on 12 v dc and the lamp is switched through a relay. /forums/images/graemlins/confused.gif
VicS
Well-Known Member
There are low voltage PIR detectors in the Maplin catalogue but they are not said to be suitable for outdoors. They have normally cloesd contacts and the "alarm" time is only 2-3 seconds.
If you could protect them from the weather and if you could build a suitable circuit to then operate the light incorprating an adjustable hold on feature then maybe there is a way forward using one of them.
If you could protect them from the weather and if you could build a suitable circuit to then operate the light incorprating an adjustable hold on feature then maybe there is a way forward using one of them.
A
Anonymous
Guest
All of the cheapest, commonest intruder PIRs run off 12V - all intruder panels have float-charged 12V accumulators, just like a boat. You need to set it to unlatched and you will need to drive a relay (12V) from the switched output. All very straightforward. Best place to get one would be a wholesale electrical distributor. If you tell them what you want to do, they will probably show you how...it is very easy. Only prob is that you will not have a photocell for night/day control, or a timer. That's why I use a standard 230V unit, bought on the high street, fed from a (sine wave) inverter.
mldpt
Well-Known Member
Hi Lemain.
I had thought of that approach, my only worry was that I might need a pure sine inverter which are expensive to light the lamp of a cheap security lamp from B & Q this is not for me as I have an alarm system with a GSM dialer on my boat, it,s for a friend who has a wood yard in the country and he wants a light and PIR to frighten of the local lads. He has plenty of batteries and machines to charge them with, so an inverter switched on at night and a security lamp pluged into that would not use a great deal of current unless the lamp was on and that would only be for a sort time. If a modified sine wave will do the job. /forums/images/graemlins/laugh.gif
Mike
I had thought of that approach, my only worry was that I might need a pure sine inverter which are expensive to light the lamp of a cheap security lamp from B & Q this is not for me as I have an alarm system with a GSM dialer on my boat, it,s for a friend who has a wood yard in the country and he wants a light and PIR to frighten of the local lads. He has plenty of batteries and machines to charge them with, so an inverter switched on at night and a security lamp pluged into that would not use a great deal of current unless the lamp was on and that would only be for a sort time. If a modified sine wave will do the job. /forums/images/graemlins/laugh.gif
Mike
A
Anonymous
Guest
[ QUOTE ]
If a modified sine wave will do the job. /forums/images/graemlins/laugh.gif
[/ QUOTE ]Don't know. Modified sine inverters blow up Braun electric toothbrushes and make some other ac power supplies run very hot (for very good technical reasons, too). Don't underestimate the risks of using modified sine inverters. I won't touch them now if there is any electronics involved. BTW, I am an electronics engineer and spent some time designing switch-mode power supplies so I do understand the issues.
If a modified sine wave will do the job. /forums/images/graemlins/laugh.gif
[/ QUOTE ]Don't know. Modified sine inverters blow up Braun electric toothbrushes and make some other ac power supplies run very hot (for very good technical reasons, too). Don't underestimate the risks of using modified sine inverters. I won't touch them now if there is any electronics involved. BTW, I am an electronics engineer and spent some time designing switch-mode power supplies so I do understand the issues.