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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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Standard PIR - 12V?
I need to know if the standard PIR you get on a halogen 240V external
light can be put onto a 12V light? I know you can buy the external PIRs on their own (rated at 1000W for example) but I just want to connect one side to a 12v battery and the other side to some 12v lighting. Also, say a lamp is 10W 12V, then this draws 0.833A. If a battery was 3000mAH, would this last for 3.6 hours? Am I correct? Thanks for any help. Mat G Birmingham, UK |
#2
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Standard PIR - 12V?
wrote in message ups.com... I need to know if the standard PIR you get on a halogen 240V external light can be put onto a 12V light? I know you can buy the external PIRs on their own (rated at 1000W for example) but I just want to connect one side to a 12v battery and the other side to some 12v lighting. Also, say a lamp is 10W 12V, then this draws 0.833A. If a battery was 3000mAH, would this last for 3.6 hours? Am I correct? You would need to disconnect the relay contact from the live rail. I modified one to operate a hall light as well as being bypassable :- http://uk.geocities.com/gentlegreengiant/PIR.GIF |
#3
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Standard PIR - 12V?
"gentlegreen" wrote in message . uk... wrote in message ups.com... I need to know if the standard PIR you get on a halogen 240V external light can be put onto a 12V light? I know you can buy the external PIRs on their own (rated at 1000W for example) but I just want to connect one side to a 12v battery and the other side to some 12v lighting. Also, say a lamp is 10W 12V, then this draws 0.833A. If a battery was 3000mAH, would this last for 3.6 hours? Am I correct? You would need to disconnect the relay contact from the live rail. I modified one to operate a hall light as well as being bypassable :- http://uk.geocities.com/gentlegreengiant/PIR.GIF just reread the OP. I wouldn't be surprised if the low voltage supply for the electronics was derived using a resistor ... You would need to do some more mods to the PCB. .. |
#4
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Standard PIR - 12V?
wrote in message
ups.com... I need to know if the standard PIR you get on a halogen 240V external light can be put onto a 12V light? I know you can buy the external PIRs on their own (rated at 1000W for example) but I just want to connect one side to a 12v battery and the other side to some 12v lighting. Sort of! If you have mains available, then you can wire the output of the PIR to a relay with a 230v coil For example http://cpc.farnell.com/jsp/endecaSea...tk=gensea rch (http://tinyurl.com/z7mte) and the base http://cpc.farnell.com/jsp/endecaSea...tk=gensea rch (http://tinyurl.com/k7bc8) Alternatively, you can get PIR's for use with CCTV and alarm systems that work on 12v, however, these usually have a normally closed (light on) connector, and then only usually activate for a few seconds. Also, say a lamp is 10W 12V, then this draws 0.833A. If a battery was 3000mAH, would this last for 3.6 hours? Am I correct? It depends on the battery, the theoretical max would probably be this, however towards the end of the charge, the light would be a lot dimmer, and if the PIR was powered from it, this may start behaving erratically! Sparks... |
#6
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Standard PIR - 12V?
In article ,
Owain writes: Maybe better using a 12V intruder alarm PIR and connecting to the lighting using a relay (the intruder alarm PIR will *not* be able to switch high currents directly) They also have no delay before switch-off, unlike PIRs designed for lighting use. -- Andrew Gabriel |
#7
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Standard PIR - 12V?
On Sun, 07 May 2006 15:57:37 -0700, djmg2 wrote:
I need to know if the standard PIR you get on a halogen 240V external light can be put onto a 12V light? I know you can buy the external PIRs on their own (rated at 1000W for example) but I just want to connect one side to a 12v battery and the other side to some 12v lighting. Also, say a lamp is 10W 12V, then this draws 0.833A. If a battery was 3000mAH, would this last for 3.6 hours? Am I correct? Mains PIRs need 230Vac but have high current (4A non inductive load) contacts. 12V PIRs (alarm system type) need only 12V but have contacts rated in mA. So you'd need a 12V Alarm PIR + a 12V relay with contacts of around 1A+. -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at http://www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html |
#8
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Standard PIR - 12V?
"Andrew Gabriel" wrote in message ... In article , Owain writes: Maybe better using a 12V intruder alarm PIR and connecting to the lighting using a relay (the intruder alarm PIR will *not* be able to switch high currents directly) They also have no delay before switch-off, unlike PIRs designed for lighting use. I want to fit a PIR in my new stairwell to switch the lights on. I suspect I will use a bog standard B&Q security light minus the light - I'm guessing specially-designed "occupancy sensors" are expensive. .. |
#9
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Standard PIR - 12V?
The message
from "gentlegreen" contains these words: I want to fit a PIR in my new stairwell to switch the lights on. I suspect I will use a bog standard B&Q security light minus the light - I'm guessing specially-designed "occupancy sensors" are expensive. The ain't cheap. I have one in the downstairs loo. Oooh, look, while googling for a price I found this... http://www.screwfix.com/app/sfd/cat/...51243&ts=96986 A security light that does LE lamps. -- Skipweasel Pay no attention to that man behind the curtain. |
#10
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Standard PIR - 12V?
"Guy King" wrote in message ... The message from "gentlegreen" contains these words: I want to fit a PIR in my new stairwell to switch the lights on. I suspect I will use a bog standard B&Q security light minus the light - I'm guessing specially-designed "occupancy sensors" are expensive. The ain't cheap. I have one in the downstairs loo. Oooh, look, while googling for a price I found this... http://www.screwfix.com/app/sfd/cat/...51243&ts=96986 A security light that does LE lamps. I suspect I will modify a cheapo Halogen light and wire it in parallel with the light switches in such a way that I can painlessly remove it in the unlikely event I ever sell ... |
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