532nm Driver

Hey guys,

Fairly new here, been reading a lot of the forums during the last few weeks learning all about building lasers. I've decided to go with one of these 532nm 3v "200mW" (cough 140mw) diodes and get rid of the driver that comes with it so I can build my own. After reading several of the DIY driver guides, I am not entirely sure which parts to buy. Some have you get a 25ohm pot while others a 100ohm pot. The capacitor voltage/capacitance also differs. And I get that you need to get different voltage/currents out of the driver for different diodes. How do you determine what capacitor specs you need, which pot you go with, what resistors, etc. I can do some of this using ohms law and the guides.

Currently, need 7.2V input for the driver according to Laser driver - It can be done. Are two CR123A ok for this?

Putting the LD spec of 250mA into the resistor calculator, this says I need a 5ohm resistor. So does this mean I use two 5ohm resistors instead of two 10 ohm resistors? Not sure since the calculator isn't for a laser driver circuit per se.

As far as the capacitor and pot goes, I have no idea. Do I want a 25ohm or 100ohm pot?
And I've seen 35V 47microfarad capacitor as well as a 16V 10 microfarad capacitor, but which of those if any will work for this driver?

I can always dust off the physics textbook, but I thought I would ask here where the experts are

I greatly appreciate any advice/tips in this matter.

(and yes I will get safety goggles for this, especially since I want to get a 445nm after this)

1. 250mA is not the input spec for the LD, it's the input spec for the driver. You're replacing the driver, so who cares what it's input spec was?
2. That input spec for the driver is wrong anyway. (all the DX greens say 250mA, even their 5mW modules)
3. You don't have a 532nm laser diode. You have a 532nm DPSS module. You have an 808nm infrared laser diode. You need a driver for an infrared diode.

So, here's what you need to do:

1. Figure out what the actual current required by your 808nm infrared laser diode is. You'll probably want to just test the driver it comes with to figure this out. From memory, on that module, it's either 340mA, or 420mA. So - check when it arrives.
2. Build a DDL driver for that level of current. Voltage wise, if you're using an LM317, you'll need about 6V of input. Supply that however you want

Thanks rhd for the fast and informative reply! Didn't realize the green lasers were mostly DPSS and that the actual diode was completely different. Still a lot to learn lol

I'll check it out when it arrives and go from there! :thanks:

Cheers

One more quick question. Since I am removing the driver, is there any point getting this one over this one?

200mW 532nm Green Laser Module (3V 11.9mm) - Free Shipping - DealExtreme
10mW 532nm Green Laser Module (3V 11.9mm) - Free Shipping - DealExtreme

edit: derp

Well, if your removing the driver you might aswell replace the diode and have an up-to spec laser.

The stock diode will probably die at high currents.

er ok so what do you recommend in that case? I am just trying to get a 532nm laser where I build my own driver. Balloon popping power is what I am looking for, but I can settle for less until I do a 445nm.

Lazerz:
Can you really just swap 5.6mm diodes? I thought there would be major alignment issues?

rhd said:

Lazerz:
Can you really just swap 5.6mm diodes? I thought there would be major alignment issues?

Click to expand...

yeah, you'll have to remove the crystal set to remove and install a new diode.

^ Well you don't need to remove the crystal set to remove the diode. All you need to do is remove the driver and use a spanner wrench to unscrew the retaining ring that holds the diode in. If you do this take note if the position of the old diode by marking the module where the notch in the diode is. This way you wont have to fiddle with rotating it.
I'd say replacing the diode isn't necessary unless your really going to push the limits of the crystal set. Just replace the driver if you want to power it with a li-ion cell since the existing driver won't last long with a Vin of >3vdc, or use one or two 1N400X diodes to drop the Vin close to 3vdc.
Hope I could help, take care and good luck!

Ramsey_innovations said:

^ Well you don't need to remove the crystal set to remove the diode. All you need to do is remove the driver and use a spanner wrench to unscrew the retaining ring that holds the diode in. If you do this take note if the position of the old diode by marking the module where the notch in the diode is. This way you wont have to fiddle with rotating it.
I'd say replacing the diode isn't necessary unless your really going to push the limits of the crystal set. Just replace the driver if you want to power it with a li-ion cell since the existing driver won't last long with a Vin of >3vdc, or use one or two 1N400X diodes to drop the Vin close to 3vdc.
Hope I could help, take care and good luck!

Click to expand...

some modules use that method to hold the diode in. But this particular module, which I have bought many times, Doesn't. It uses a press fit.

In that module, what do you think the IR diode would be? A 300mW, or a 600mW ?

What is the IR (mW optical) to 532 (mW optical) efficiency range? I don't often see it discussed in those terms.

Nocturnal said:

some modules use that method to hold the diode in. But this particular module, which I have bought many times, Doesn't. It uses a press fit.

Click to expand...

Really, wow your right, my apologies sir That's ironic, I just got one of these from o-like the other day but haven't had a chance to do anything with it yet. I foolishly assumed they were all held in with a retaining ring just as the two other variations I had received in the past were. I'm looking at it now and you are correct, sorry.

ok now I am even more confused than before hahaha

so what parts should i buy for this thing? I'll follow the standard DDL driver guide for the driver. I am rather confused about the diode/DPSS....

lol dude i see a dead module verry soon and more dumb questions about why it's not working anymore




ps : oh im so sorry

Well I havent pushed the order button on anything just quite yet

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