Building my quad

[badger1666]

Won't that burn out the resistor in the long term?
P=IV and all that...
e.g. >~1W for reds?
& >~5W for blues?

well mine dont even get warm @350ma ,even after 10hours straight at last lem
then again theres a fan running
i just went with robins recomendation

[andy_con]

i just went with robins recomendation

+ 1

[edison]

Alright so 0.5 watt seems to be enough I will go to the shop and see what they got

So my lasever drivers isn,t suitable because it not an highside driver???

[badger1666]

Alright so 0.5 watt seems to be enough I will go to the shop and see what they got

So my lasever drivers isn,t suitable because it not an highside driver???

might not hurt to go a little higher on the resistor rating to play safe
and keep them in air flow

as for your driver dont know enough about your setup to comment
but if those diodes are not isolated from each other and ground then no its not

[Doc]

I use 2ohm 1W in my red multi

[dnar]

I used 1 ohm 1/2w in my quad red. At 450mA per diode the v drop across 1 resistor is 0.45V. Power dissipated is therefore 0.45 x 0.45 = 0.2W.

If you use metal film resistors, they are typically 0.5W and much more reliable than carbon types.

As Mccarrot pointed out, the down side with parallel diodes is should one fail, the remaining 3 diodes take an increase in drive current, so it could run away creating an "Andy_con" moment.

[edison]

Thanks Dnar thats makes sense!

I use electronic circuitboards and so the diodes are mounted on a electronic circuitboard so im sure there is not a problem running them parallel. I,m waiting for andythemechanic to finish his quad driver with TEC but if he doesn,t finish it i will find a highside driver schematic or a chip so that a company can develop a quad driver. I know that the PICO drive is there but i want to have a 4 channel instead of a six.
Since most people building a quad there is much demand for a 4channel driver with tec included. Or maybe i will go with a 1 channe highside driver and tec. The development of the mechanics are more important to me then the driver.

[MisterWilling]

I used 1 ohm 1/2w in my quad red. At 450mA per diode the v drop across 1 resistor is 0.45V. Power dissipated is therefore 0.45 x 0.45 = 0.2W.

If you use metal film resistors, they are typically 0.5W and much more reliable than carbon types.

As Mccarrot pointed out, the down side with parallel diodes is should one fail, the remaining 3 diodes take an increase in drive current, so it could run away creating an "Andy_con" moment.

I am running 6 LPC diodes in parallel using .5W 1ohm resistors with just one flexmod P3. I have been running them at 185-200mW for about 10 hours solid with no problems but I have not yet tested them under modulation.

[edison]

Hello guys here are some pictures of my quad shooting it on our toilet door from the hall way true the kitchen. The beam is 3 x3 mm at aperture and the size was 12mm at 12meter so 0.75mrd it has a tec underneath it and will be driven by a flexmod.