Identifying LED array for flashlight project

Thread Starter


Joined Apr 16, 2013
Any way to identify specs of led array without any markings ?
I have here a halogen replacement led array with a driver that may be blown and plan reusing array if its alive.
The "bulb" in question is Bell LED R7s-13w 2700k, plugs into standard halogen socket.
The array is circular pcb with 32 leds, 50mm across, the only marking on it is A154A.

Ideas ?


Joined Sep 7, 2010
The manufactures wattage listing cannot be trusted on these units ... "13W" almost certainly does not consume 13W..

The best way is to connect to a variable voltage supply and increase the voltage till the current x voltage shows about 3W .. Leave it running for 5 mins and if the aluminium backing plate is not too hot increase voltage ... repeat this until the backing is so hot it's just not possible to keep your figure pressed on it ... this is a fairly acceptable running wattage for a long life .


Joined Mar 10, 2018
Low cost investment is IR thermometer. Basically there is a thermal R between
base plate and Tjunction, you might be able to fudge Tj measurement by making
a simple mask such that thermometer only sees the die. You would also need to
investigate weather or not white LEDs generate much IR which would compromise
the measurement.

Keep in mind the IR sensor measures emissivity of the source, that would be the
lens over the LED, so unless its closely coupled thermally that constitutes another
error source.

Regards, Dana.