Powering a P60 from a DC source

[harshad1]

Hello all,

I have a P60 with the following specs:

High Power 3 Watt Cree
2.7-8.4V input voltage
(Direct drive under 3.6V)
2xCR123A, or 2xRCR123

I want to power it using a DC power supply. Since it is rated at 8.4V and 3 watts, Is it safe to power it directly using an 8V ~5A power supply? i.e. nothing between the power supply and the P60 leads (springs)?

What does 'direct drive' really mean in this context?

Thanks

 

[UberLumens]

Direct Drive under 3.6 means:
When the input voltage is less than 3.6v it will run directly off the batteries(think the old flashlights that dim as you use them) in other words the regulator "turns off".

8v at 5amps is about 40 watts way too much if it puts out constant current.

 

[harshad1]

By 8V 5A, I meant the maximum load the power supply can handle. I assumed that simply connecting an ~8V DC source with sufficient capacity would suffice and the drop in would draw whatever current it needed...

If that isn't the case, what should be the characteristics of the power source in order to drive the system at the full 3 watts? i.e. what should its voltage and output impedance be?

 

[UberLumens]

If its 5amps max you should be just fine, most supplies are like that as you seem to know.

I made my recommendation on the side of safety, if you know its not a CC supply go for it.

You may want a smaller supply though, there are usb "wall warts" that would most likely run cooler and still do the job easily