Driving 10 (5mW, red) laser diodes

Hi!

I need to use 10 laser diodes, here's the specs:

Laser Power 150mW
Size ·6-10.5
Spot mode Point-like spot, Continuous output
Laser wavelength 650nm(red)
Power <5mw
Supply Voltage 50 VDC (maybe max rating??)
Current <40mA

First of all, i made this calculation: one diode needs 150 mW. If i have a 5V supply, i should give 30 mA (150 mW / 5 V).
So, for 10 diodes in parallel, i should use a power supply which gives 30 mA x 10 diodes = 300 mA @ 5V.

...is it correct?

Please tell me if it is correct, and then i can talk about the power supply circuit (it may become confusing )

Thank you! :thanks:

If they require 5 volts dc on the input, you are probably using a lasser doide with a driver built in there somewhere. These drivers can be small enough to fit rather small laser diode enclosures, but are surely there if they run off 5 volts.

30 mA current per diode + driver circuitry is not a strange value, so if you run 10 of them in parralel you could be looking at 300 mA supply current.

The best thing to do is to actually measure the current draw from one of these units though, as it could be a fair bit less than 30 mA, or all the way up to the specced 40 mA depending on what diode is in there and how the driver was constructed.

Benm said:

If they require 5 volts dc on the input, you are probably using a lasser doide with a driver built in there somewhere. These drivers can be small enough to fit rather small laser diode enclosures, but are surely there if they run off 5 volts.

Click to expand...

I think you're right, i bought this, i can see a small board inside the head and in the title it says 5V: Mini 650nm 5V 5mW Laser Diode Light Module Head Red for Raspberry Pi Arduino NEW | eBay

So, what if i use a simple lm7805 voltage regulator, without any current control? 7805 can source about 1.5A with heatsink.

Those seem like the ones with control circuits built in that run off 5 volts straight, so you can use your 7805 regulator with just its two buffer caps and be done with the power suppply.

They also market them to be driven directly off arduino's so the current draw will probably be 30 mA or less each.

definitely post some pictures when you finish building it!