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Mike, Master Electrician
Category: Electrical
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Experience:  Licensed Master Electrician - OnQ Certified Data Voice Audio Video Installer
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I wish to use two lasers in parallel. I want to power them

Customer Question

I wish to use two lasers in parallel. I want to power them with 4.5 volts dc. What is the max amperage that I can use and still qualify for an FDA Category 3a or 3R rating that limits the output at 5mw? This is beyond my pay grade. Thanks
Submitted: 1 year ago.
Category: Electrical
Expert:  Phil replied 1 year ago.
Hello a Bob, is that 5 Megawatts? if so those lasers will be large enough to vaporize a volkswagen at 2 miles... if you are thinking of something much less powerful, please attach your FDA reference to save me the hours of research needed to find it. We can go from there if you like.
Customer: replied 1 year ago.
Phil, Thanks for your response' I love it? It was my understanding that the FDA Category 3R (which is in the range of laser pointers) limit is 3 milliwatts vs megawatts which is incredibly tight. Am I mistaken?
Customer: replied 1 year ago.
I have a call into FDA already for clarification. They will call back tomorrow. I will absolutely communicate with you when I hear back. Thank you
Expert:  Phil replied 1 year ago.
Hello again, without knowing the specs on the lasers you are using this could end up being a wild goose chase with results out of context with what you are doing... notice the 1700 different types of devices covered, then notice the complex list of exceptions... without any clue as to what you are building I will be hard pressed to wade through that pile of paper work to make any sort of a recommendation. Preliminarily, I would build it first, measure the milliwatts then do the research on the paper work requirements. I will look forward to hearing from you.
Customer: replied 1 year ago.
I agree. I'll speak with FDA in the morning ..or whenever they call ...and call you after with more detail. What is important to me is your familiarity with lasers. I need to power the lasers it to emit a strong beam under a certain environment and yet to not burn the lasers out. Call you when I know something.
Expert:  Phil replied 1 year ago.
Hello again Bob, I am not a laser tech. we may not have any here. That said, if you supply the lasers with the specified voltage they will not burn out... then you can supply that voltage reduced through a potentiometer to reduce the laser output. How low a voltage you can go and still have the lasers work will be a function of what you buy... testing will be required. How you control the potentiometer will be up to you and what sensors you use to tell the laser that it needs to reduce power. I can opt out if you like, now or later. we can go from there.
Expert:  Phil replied 1 year ago.
I think the cutting capability of most lasers is controlled by the power input pulse rate, not primarily by reducing the voltage supplied.
Customer: replied 1 year ago.
You sound like a pretty knowledgeable guy. But in this case, I need someone who is really close to the laser world. I think you can get there but there may be wrinkles and dead ends that my cost me time. I am going to look for, as you said, a 'laser tech' or engineer. Thanks and we may get back together on a related but different topic.Bob
Expert:  Phil replied 1 year ago.
Thats a good idea Bob...I wish you the best with the project.
Expert:  Martin replied 1 year ago.
Hi. I think what you really want to know is about the parallel notion. Are you meaning a parallel electrical configuration or literally make two laser shoot in the same direction with the two light beam parallel to each other?