New diode laser driver available: FlexMod 1!

[drlava]

How much for pre-built?

Hi,
$40 shipped to CONUS, $45 shipped internationally. They can also be pre-set to your desired threshold current and max current if desired.

[thesk8nmidget]

can you run two diodes with one driver?

both the diodes would need the same power and same modulation.

im thinking a dual red or a dual 405nm

[drlava]

Hi, yes you can run many diodes of the same type from one driver, just stay within the current limitations of the driver (5A max)

Each diode is slightly different so to even out the current draw between the diodes when they are in parallel, you should put a (thick) metal film resistor in series with each diode. This is true for driving parallel diodes no matter which driver you use.

Let's say you are making a super red and want to use as many red diodes as possible, and you want the max current to be 350mA to each diode, and the lasing threshold is 75mA. Choose a resistor so that it drops about 10% of the diode voltage at the idle current, or 0.3V at 75mA: 4 ohms. Then calculate its voltage drop and power disipation at full power: 4 ohms*350mA = 1.4V; 1.4V*350mA= 0.49W

So, for an array of open can diodes you should use 4 ohm, 3/4 or 1W resistors in series with each diode. Maximum number of diodes on one driver is 5A/350mA = 14 diodes.

Minimum power supply voltage for the driver would be 3V (diode voltage) + 1.4V (resistor voltage) + 2.5V (Driver requirement when delivering 5A) = 6.9V

Finally, your diodes should be of the same make and model, and thermally coupled so they stay close to the same temperature. They should be connected to the same size heatsink block and with the same length and type of wire.

[thesk8nmidget]

alright that makes sense i think

can you tell me what a good resistor for 2 803t diodes at 190ma would be?

and just to clear this i want to set the 0 bias knob to what a 803t diodes starts lasing at correct? do you know what a good setting would be for this?

[drlava]

alright that makes sense i think

can you tell me what a good resistor for 2 803t diodes at 190ma would be?

and just to clear this i want to set the 0 bias knob to what a 803t diodes starts lasing at correct? do you know what a good setting would be for this?

Choose a resistor so that it drops about 10% of the diode voltage at the idle current

You want the 0-bias current to be a little below lasing threshold.

[wes]

this sounds like just i will need.
i can replace and upgrade the blown red in my old rgy beam box.
it sounds like if i find what diode i will use,you can set the driver for me and i can assemble the two together with my very remedial electronics knowledge.

is this a correct assumption?
will you be selling these on an ongoing basis?

i am ignorant as to diodes.
i have an integrated power supply/driver for my dpss greenie.
what will i need as a power supply?
do you also sell compatible power supplies?
or is there a pretty much generic supply everyone uses?
small would be good.

if you only answer one of my questions i would just like to know if you will be selling these drivers ongoing.

peace,
w

[thesk8nmidget]

have bought a few from dr lava and he has always gotten them and any other drivers i have ordered to me in a week.

you can order here and they come assembled

http://hacylon.case.edu/ebay/laser_diode/FlexMod01.php

[drlava]

>is this a correct assumption?
Yes
>will you be selling these on an ongoing basis?
Yes, that is the plan, as long as there is a need

>what will i need as a power supply?
You can use any power supply 5-12V. 5V is reccommended for 1.8V IR pump diodes.
There are some here from 2A-8A

[MechEng3]

I like the driver....board seems to like solder though...the green area seems very sticky. The modulation has a few issues that could be just a component. My green laser seems to leave a trail and the red and 473 do great, same driver all 3 lasers. I have anther here...may swap it out and see if I get the same results. Got a TEC driver designed for me to try yet? I picked up a few of the Wavelength HTC-1500.....it does well , but a little more robust driving power like 5 or 6 amps would be nice. It's funny this driver doesn't ring like a lasever driver. O'scoping signals and output ranges soon.
Let me know if you get a different PCB coating/manu.....either way I will want more soon.Thanks for a great unit.

[drlava]

Hi, I'm glad you like them. The modulation issue with the green laser leaving a trail, have you tried decreasing the 0-Bias? What power supply and supply Voltage are you using? It may need to be slightly higher than you are using to get the full 5A. Also, since you have an oscilloscope, you could carefully try 2 drivers in parallel, with a test load for up to 9-10A! Some tweaking may be required to make it work well.