Driver for an RGB laser, optlasers schematics?

[lostbeam488]

I'm trying to build an rgb laser, with a Sharp GH0637AA2G, NICHIA NDB7875, and a Sharp 5GH05C01A9G. I'm having trouble finding analog controlled drivers for these diodes, and analog control is a must for an rgb laser. I found the optlasers analog drivers such as the LPLDD-5A-12V (single channel) and the LPLDD-5A-16V-3CH (triple channel), which are exactly the kind of drivers I need. However, they are very pricey for a tiny pcb driver. Does anyone have the schematics for these drivers, is there any way to find them, or are there any open source drivers like these that I can order a pcb for and make myself? Or are there any other cheap alternatives?

 

[WizardG]

What's your input for the analog driver? You could just use a power transistor, with a resistor in series with the diode that would be of an appropriate value to set a hard upper limit on current through the diode.

 

[lostbeam488]

What's your input for the analog driver? You could just use a power transistor, with a resistor in series with the diode that would be of an appropriate value to set a hard upper limit on current through the diode.

I'm wanting to use a 12v power supply, so Ideally each analog driver takes 12v in, and uses a 0-5v modulated analog signal from a micro controller. And by using a power transistor and resistor, do you mean using a mosfet to control a driver output to the laser diode, or do you mean using the resistor as the current limiting circuitry by itself?

 

[WizardG]

I'm talking about using a MOSFET, or even a bipolar transistor, to control VOLTAGE to a diode and resistor in series. The resistor should be sized to set the upper limit on diode current when the transistor is switched fully on.

 

[paul1598419]

Many of these aren't changed using an analog current shift, but use TTL pulse width modulation to effectively change the apparent outputs of each laser. This is pretty easy to setup and you can even find the TTL modulators on eBay.