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ArcticMyst Security by Avery

DIY Driver 5 Selectable Ranges

Joined
Mar 22, 2011
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Hello LPF Members. As you read in the title, this is a select-able 5 range diy driver!

Don't get too excited though. This isn't a "DIY Flexdrive" or anything of that sort. It's an LM317 based driver. This is just my take on it.

Components I used

LM317
10 Ohm resistors
15 ohm resistors
2 Pole 6 Throw Rotary Switch
Illuminated Switch (optional safety feature)
Alligator Clips
1n4001 Diode
10uf Electrolytic Capacitor

This whole project cost me about $15 to make which isn't too too bad for a driver this versatile!

Each mA range is varied due to slight resistor variation.
They would ideally be...

83 mA ~ 15 ohms 1/4W resistor
125 mA ~ 10 ohms <1/4W resistor
210 mA ~ 6 ohms <1/2W resistor
330 mA ~ 3.75 ohms <1/2W resistor
410 mA ~ 3.1 ohms <1/2W resistor

You can achieve the 6 ohm, 3.75 ohm, and 3.1 ohm settings by wiring resistors in parallel.

6 Ohms - a 15 ohm and a 10 ohm
3.75 ohms - a 15 ohm and 2x 10 ohm
~3.1 ohms - 2x 15 ohm and 2x 10 ohm

If there are a few requests, I'll post the build schematic for the driver on this thread

ipod+025.JPG


The "Off" selection on the rotary switch turns the whole device off. When you turn it to a mA range the red switch lights up. Before you can turn the laser on, you must also turn this switch on. It serves as an extra safety feature to ensure you KNOW if the laser diode will be on.

ipod+027.JPG


These are the voltage input supply pins. It's not an ideal set up, but works. I will improve upon this part of the driver later on. Perhaps with battery holders or a DC jack.

ipod+026.JPG


Output leads to connect to a diode. I know connecting alligator clips to a diode is both stupid and hard given its size, case voltage supply, and sensitivity if shorted. However, just solder wires to the diode and you can safely connect the diode to the driver.

ipod+028.JPG


This just shows the voltage requirements for each diode type. This driver can be supplied with over 12V if needed. However the LM317 will turn the excess power into heat. This is not a problem if you properly heat sink it with a transistor heatsink, or if you want to use a metal housing and screw the LM317 into the case. However that would complicate the layout as the heatsink on the LM317 is electrically connected to its middle pin.

Just wanted to share this! :thanks:
 





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Nice DIY driver build! Looks like you put quite the effort into it. Are you planning to incorporate this driver in a laser build soon?
 
Joined
Mar 22, 2011
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Nice DIY driver build! Looks like you put quite the effort into it. Are you planning to incorporate this driver in a laser build soon?

The whole thing was completed within 18 hours of it's rough conception to final product. I'm planning on redesigning the case and changing the ranges a bit to be more versatile.

I'm planning on using it as a test driver before incorporating diodes into hosts. That way I can confirm the diode isn't defective or damaged before soldering it in it's final home.

Also my dad's computer parts bin had a spare CPU heatsink/fan so I'm going to build another selectable range driver and use that driver along with the heatsink to have a high powered laser burner with a high duty cycle!
 
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Joined
Oct 6, 2009
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This looks like a nice alternative for a bench powersupply to test diodes.:gj:

Expanding this to more range settings might even make it more versatile for higher power diodes.
 
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Looks good! I just built something similar the other day, using a LM317. Instead of using a multipole switch i just used a rheostat to control current, i get a non linear ouput range of 50~1200mA.

What are you using to power this driver?
 
Joined
Mar 22, 2011
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Looks good! I just built something similar the other day, using a LM317. Instead of using a multipole switch i just used a rheostat to control current, i get a non linear ouput range of 50~1200mA.

What are you using to power this driver?

That's good idea to incorporate into a driver, a rheostat!

But on mine I just preferred the preset ranges because then I know what output is being supplied.

I'm powering it with batteries right now until I find a DC jack and a wall plug with suitable mA and Voltage outputs.
 




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