by ericmark »
Tue May 03, 2016 10:53 am
Simple answer is yes, however the existing PIR will have either a solid state or mechanical relay with a maximum rating. You don't know what that rating is so if you draw power from it you could cause an overload.
My outside light was designed to take a 110 Watt quartz lamp. It has a 5W LED lamp, so I could run another 21 lamps off the PIR without overload.
However I find the main problem is getting a PIR to see me but not see people passing on the road. So at the 10 ~ 15 pounds for a ready built LED lamp with PIR built in I would use a second PIR.
Over the years I have found the PIR is the weakest link, again and again the PIR fails but the lamp is OK. If the PIR has a relay i.e. you can hear it click then connecting up two PIR's is helpful. Assuming they are not overloaded.