DIY Laser Diode Driver || Constant Current Source

64,939

708

17

Introduction: DIY Laser Diode Driver || Constant Current Source

About: Awesome Electronics Tutorials, Projects and How To´s

In this project I will show you how I extracted a laser diode from a DVD Burner which should have the power to ignite a match. In order to power the diode correctly I will also demonstrate how I build a constant current source which delivers a precise and steady current to the load. Let's get started!

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Watch the Video!

Thie video gives you a good overview of what you need to do to make your own constant current source and how to get a "burning" laser diode. In the following steps I will give you additional information about the most important aspects.

Step 2: Save All the Useful Parts From the DVD Drive!

You never know what your next project might need for components. So it is the best to save the 3 motors, neodymium magnets and diodes you find inside the drive.

Step 3: Order Your Parts!

Here is a list of all the parts that I used during this project (affiliate links):

Ebay:

1x Laser Module:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Vero Board:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x MCP602:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 3.3Ω / 5W Resistor:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 1kΩ Resistor:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x IRLZ44N N Channel MOSFET:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x Screw Terminal:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 500kΩ Potentiometer:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Laser Safety Glasses:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Thermal Paste: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

Aliexpress:

1x Laser Module: https://s.click.aliexpress.com/e/_dZlipG7

1x MCP602: https://s.click.aliexpress.com/e/_d7gXXAP

1x 3.3Ω / 5W Resistor: https://s.click.aliexpress.com/e/_dVdbbC3

1x Vero Board: https://s.click.aliexpress.com/e/_dWvCu9h

1x 1kΩ Resistor: https://s.click.aliexpress.com/e/_dYW3fCj

1x IRLZ44N N Channel MOSFET: https://s.click.aliexpress.com/e/_dSubBCb

2x Screw Terminal: https://s.click.aliexpress.com/e/_d8g2zdz

1x 500kΩ Potentiometer: https://s.click.aliexpress.com/e/_BfhVhtCx

1x Thermal Paste: https://s.click.aliexpress.com/e/_dViWRGj

Amazon.de:

1x Laser Module:http://amzn.to/1cUjekU

1x MCP602: -

1x 3.3Ω / 5W Resistor:http://amzn.to/1cUjhgD

1x Vero Board:http://amzn.to/1yZ4k1J

1x 1kΩ Resistor:http://amzn.to/1cUjjVL

1x IRLZ44N N Channel MOSFET:

2x Screw Terminal:http://amzn.to/1GtRU9R

1x 500kΩ Potentiometer:http://amzn.to/1yZ4Vkb

1x Laser Safety Glasses: -

1x Thermal Paste: http://amzn.to/1fay0FP

Amazon.co.uk:

1x Laser Module:http://amzn.to/1fazakN

1x MCP602:http://amzn.to/1L88WcE

1x 3.3Ω / 5W Resistor:http://amzn.to/1TlDywV

1x Vero Board:http://amzn.to/1TlDGwj

1x 1kΩ Resistor:http://amzn.to/1cUkzbm

1x IRLZ44N N Channel MOSFET: -

2x Screw Terminal:http://amzn.to/1cUkF2w

1x 500kΩ Potentiometer:http://amzn.to/1TlDVYi

1x Laser Safety Glasses: -

1x Thermal Paste: http://amzn.to/1fazvnw

Step 4: Build the Circuit!

Here you can find the schematic for the LM317 and MCP602 constant current source. You can simply build the circuits according to the schematics or you can use my board layout for the MCP602 circuit.

Step 5: Connect the Laser Diode/Test It!

Now just hook up your laser diode to the load terminal of the circuit and you should be able to control the current flow by adjusting the 500k potentiometer.

Step 6: Success!

You did it. You just created a constant current source to power your LEDs or Laser Diodes.

Feel free to check out my Youtube channel for more awesome projects:

http://www.youtube.com/user/greatscottlab

You can also follow me on Facebook, Twitter and Google+ for news about upcoming projects and behind the scenes information:

https://twitter.com/GreatScottLab

https://www.facebook.com/greatscottlab

Be the First to Share

    Recommendations

    • Backyard Contest

      Backyard Contest
    • Silly Hats Speed Challenge

      Silly Hats Speed Challenge
    • Finish It Already Speed Challenge

      Finish It Already Speed Challenge

    17 Discussions

    0
    baecker03
    baecker03

    4 years ago

    the design works, but is pretty inefficient since the mosfet will be partially open and therefore dissipate a lot of heat. there are other constant current switching supplies that would be a better alternative.

    0
    John T MacF Mood
    John T MacF Mood

    Reply 4 years ago

    baecker03, you make a good point, but the whole idea is doing this on a budget of as close to zero as possible. Yes, switching power supplies are more efficient, but they have their drawbacks too. They throw off RFI "hash" like mad, depending on the frequency they switch at.

    The driver circuit that the author has designed and showed us is more than adequate to protect the laser from over-current and voltage fluctuations.

    0
    Udon
    Udon

    Reply 1 year ago

    But using such an over-sized MosFet and then only running it partially switched actually increases your budget. In this case, a similar-packaged power transistor ripped out of some old circuitry would have not only been free, but would be more efficient, no?

    0
    Xazas.
    Xazas.

    2 years ago

    I learned a lot through your instructables and Youtube channel so thanks a lot.

    Question about this one: Can I supply the reference Voltage for the Op-Amp from an Arduino Digital Out pin and that way switch the laser on and off quickly? Or could this damage the Arduino? Or do you recommend another method for switching the laser?

    0
    Yonatan24
    Yonatan24

    4 years ago

    5:20 How sad :(

    1
    John T MacF Mood
    John T MacF Mood

    Reply 4 years ago

    And both the author, and us, learned something very good. Sometimes it takes 3 or 4 drives to get a good working laser module, and then fine tune it right.

    0
    JS7777
    JS7777

    4 years ago on Introduction

    Where do you buy you steel wire for making connections ?

    1
    John T MacF Mood
    John T MacF Mood

    Reply 4 years ago

    Sometimes people mistake tinned solid copper wire for steel, if it bends really easily, it's likely tinned or plated copper. If it's tougher to bend it's not copper. Use copper, better conductor and it won't corrode like steel or iron (ferrous metals).

    The leads on resistors and some other components are copper, but don't have a copper color because they're plated or tinned.

    0
    Notbob
    Notbob

    Reply 4 years ago on Introduction

    You don't have to use "steel wire" for this, regular copper wire works fine. If anything, you shouldn't use steel due to its poor conductivity compared to copper wire.
    Usually jumper wires like those seen in this instructable are made from the longer clipped off leads trimmed from components like resistors, but copper wire segments would work just as well.

    0
    John T MacF Mood
    John T MacF Mood

    4 years ago

    Very nice work, and plenty of explanations.

    Keep up the good work!

    I've got a nice but sadly non-working Blu-Ray drive I am gioing to dissect and see what I get following your plan. The motors quit, but the laser seens operational. And I agree, harvest all the parts that may come in handy in future projects, you never know when a magnet will be neeeded!

    0
    tp.pa.12
    tp.pa.12

    4 years ago on Introduction

    I have a question for you Please. Couldn't just so called hack a USB cord, snip off on end, strip sheild off & find + & - to power it?

    Thanks

    Tp

    0
    GreatScottLab
    GreatScottLab

    Reply 4 years ago on Introduction

    You can power the constant current source like this. But if you are using a usb port of your computer then you can destroy it if something goes wrong.

    What is the mosfet for? I built one but it didn't light a match could it because it didn't have a mosfet? Nice pics by the way!

    0
    GreatScottLab
    GreatScottLab

    Reply 4 years ago on Introduction

    Take a look at the constant current load video. There I explain the circuit.

    0
    nqtronix
    nqtronix

    Reply 4 years ago on Introduction

    The mosfet is used to regulate the current.

    The MCP602 measures the voltage across the 3.3ohm resistor, which is related to te current flowing, and regulates the resistance of the mosfet untill the set value through the potentiometer is reached. Of course, it's a little more complex, but that's how the circuit works in principle.