Hi all, I’m pulling my hair out. I’m new to electronics and may have dived in a bit too deep for my first project but am hoping to learn along the way. I want to use an internal PIR sensor to activate a 50w LED on a 12v circuit . I started using a relay but I worked out the voltage (drop) coming from the NC on the PIR was so small that the relay was unable to notice it and therefore didn’t activate. I read that I should try a MOSFET. So I am. But this is t working either. I’m using a P channel MOSEFT. Hopefully that’s the right one? Can anyone please advise me how to make this solution work? Any help would be hugely appreciated.
Sketch a circuit to further explain how you are using the PMOS
You may also want to look at a 50W LED driver that has a Logic level enable/disable. Then you will not need to worry about power switching.
Hi Luke I’m using a F5305S PMOS Trigger Switch Board MOS FET Switch Module 3V 5V 12V 24V 36V DC. I’ll do a sketch and attach mate
The solution is a standalone battery powered 12v.
I have done similar. In my case I wanted some additional logic as I was controlling three sets of LEDs so I had the PIRs feed into a micro controller and then the micro triggered the relays via an N-Channel MOSFET.
It would be helpful if you have a link to the product information/datasheet for the PIR sensor you are using and any other details about the parts you have available/are trying to use.
Which PIR module or sensor are you using, and what voltage do you need to power it? To power a 50W LED from 12V you need on the order of 4.17A, which is doable with MOSFETs or relay modules that have built-in drivers.
If you don’t already know, a 50W LED is going to get hot, so you’ll need some form of heatsinking to pull the heat away to avoid premature failure. For that matter, you’ll probably need to use a well-regulated power source for the 12V.
Hi jospeh and co, thank you for your replies and help. I’m having issues posting a link to the data sheet of the PIR and the forum wont allow me to post media. I’ll keep trying, thanks for your patience.
Since you’re a new user, the system is auto-flagging you as a spammer for trying to post repeated links (sorry about that).
For now, you can put the MPN here.