Powering Several Lasers

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Rivet
 
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Powering Several Lasers

Post by Rivet »

Hi all! I didn't know whether to put this in the laser forum or here, but since it's a request for help, here it is.
I have six lasers that I'd like to power through a single circuit. (I only have one on-off button.) The lasers are these: https://www.adafruit.com/product/1054 ones. 4.5 volts powers two lasers just fine, but if I add more lasers the circuit breaks and none of them turn on. My question is: can I up the voltage to a sufficient amount to power six lasers without frying some of the diodes? I apologize if this is self-evident, I don't know much about electronics. Speaking of which, can you suggest an online resource for me to learn more about it?
Thanks very much!

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adafruit_support_bill
 
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Re: Powering Several Lasers

Post by adafruit_support_bill »

How do you have the lasers wired? What is your power source?

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Rivet
 
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Re: Powering Several Lasers

Post by Rivet »

The power source is 4.5 volts in the form of three AA batteries. The lasers are wired in series. Thanks!

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adafruit_support_bill
 
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Re: Powering Several Lasers

Post by adafruit_support_bill »

The lasers are wired in series.
That's the problem then. Try wiring in parallel. With 3 in series and a 4.5v source, the lasers will only see about 1.5v each - not enough to light them up.

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Rivet
 
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Re: Powering Several Lasers

Post by Rivet »

That worked, thank you! Sorry for my extremely noobish question.

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adafruit_support_bill
 
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Re: Powering Several Lasers

Post by adafruit_support_bill »

We were all 'noobs' once. keep at it, and happy hacking!

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mrcarton
 
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Re: Powering Several Lasers

Post by mrcarton »

This is sort of a new question, but also sort of a variation on this one.

Instead of 3 of the 5mW 650nm Red Laser Diodes, I need 23 of them. I understand that I should wire them in parallel so the voltage stays consistent. Can I use this 5V 2A (2000mA) switching power source to power them: https://www.adafruit.com/products/276 ?

I read the power source learning page, and this one is a switching supply so it should output near the 5v it says right? I also think that I need to multiply the milliamps by the number of diodes I have (23*25mA = 575mA), and that should be less than the 2000mA that this supply requires.

Am I doing this correctly, or do I also need other things?

Thanks!

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adafruit_support_bill
 
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Re: Powering Several Lasers

Post by adafruit_support_bill »

Your calculations look correct. That supply should do the job for you.

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