Double Resistor for Red P4

[Darth Enab]

I just got my saber parts in today, (yay! ) but I was told with my 1 ohm 2 watt resistor I might blow up my P4. Source voltage is 3.6 volts. I was wondering if I could double resistor and use a 0.47 ohm 5 watt resistor. Could it work?

[Azmaria Dei]

in theory yes, but i would urge you to just use a single resistor to prevent the possibility of complications.

[Rhyen Skytracker]

You need to have both resistors at least 2.5 Watts and you need a 1.1 or greater resistor.

[strengthofrage]

Would this fall under the "path of least resistance" rule?

I think you would have an easier time just using the proper resistor instead of doubling up.

[PhoenixReborn]

Just use a 1000mA buckpuck. It slightly overdrives the P4, but the P4 can handle it.

[Azmaria Dei]

Just use a 1000mA buckpuck. It slightly overdrives the P4, but the P4 can handle it.

i've heard some people say their red P4 takes that well and i've heard others report letting the purple smoke out. also, the resistor option is MUCH cheaper, and i think that might be one of the deciding factors here...

[Rhyen Skytracker]

The Red P4s are very sensitive and you can't overdrive them much at all. I have had some work directly off of a MR FX board and only use 5 of the - wires and it worked fins and I have had others the fried with the same set up in less than 2 seconds. It is up to what risk you are willing to take. A buck puck should be fine since it is a true LED driver and regulates the current, but with other set ups be very careful.

[polarcupz]

The Red P4s are very sensitive and you can't overdrive them much at all. I have had some work directly off of a MR FX board and only use 5 of the - wires and it worked fins and I have had others the fried with the same set up in less than 2 seconds. It is up to what risk you are willing to take. A buck puck should be fine since it is a true LED driver and regulates the current, but with other set ups be very careful.

Would you suggest a 700 ma buckpuck on top of a fx board with a 3.7v Li ion and a red p4?

[cardcollector]

Just sO you know, you can feed p4s up to 1000ma without damaging them. But if you give them just a little bit over the rated voltage... Bye-bye led...

[Azmaria Dei]

polarcupz - i would suggest an MR board with a 1 ohm 2 watt resistor and a red P4. the MR board will put out (normally) 1000-1200mA at 3.5V so resistoring it based on that brings it down to just what the LED wants (and can run at safely)