I am making great progress on my laser maze and have started to hook up my 532 nm 5mW lasers.
I am beginning to wonder if my great deal on ebay may backfire a bit. I have asked a few questions from the seller and have received no answer, so I am wondering if someone here can give some advice.
The spec sheet for the modules states: Working Current 280<mA @ 3V input.
I have a 5V 4A supply that I have been using. First, I will explain what I did to size the resistors and then I have a few questions (assuming the first part isn't whacked).
I assumed a 3V drop since that was the specified input V. The power supply measures 5.14V so I came up with 5.14-3 = 2.14V. I then divided by .28A and the result was 7.64 Ohms. I went with the standard 10 ohm resistor.
Several of the modules were very dim or not lighting at all (I could see they were trying - red glow, but no light). After double checking my calculations, I realized the 10 ohm resistors calculated at 214 mA. My thought was perhaps I was not providing enough current, so I used two 15 ohm resistors in parallel to get 7.5 ohms.
This seemed to help as I was able to get a few to provide good light, but several can still not be used.
In all cases, when I quickly use a straight 5V supply, each and every module lights great - I only verify light and shut off asap.
I have tried to get clarification regarding the way the working current is listed: 280<mA @ 3V. So, without getting feedback from the seller, I am looking for some guidance.
Would the 280mA be a minimum required for operation?
Is there a typical range that laser modules have with regard to current?
Is it a tradeoff between brightness and module life?
I realize every module will not be the exact same, so am I stuck with trying each one or is there some way to use my meter to determine the units that seem to require more than 280mA?
Thanks
I am beginning to wonder if my great deal on ebay may backfire a bit. I have asked a few questions from the seller and have received no answer, so I am wondering if someone here can give some advice.
The spec sheet for the modules states: Working Current 280<mA @ 3V input.
I have a 5V 4A supply that I have been using. First, I will explain what I did to size the resistors and then I have a few questions (assuming the first part isn't whacked).
I assumed a 3V drop since that was the specified input V. The power supply measures 5.14V so I came up with 5.14-3 = 2.14V. I then divided by .28A and the result was 7.64 Ohms. I went with the standard 10 ohm resistor.
Several of the modules were very dim or not lighting at all (I could see they were trying - red glow, but no light). After double checking my calculations, I realized the 10 ohm resistors calculated at 214 mA. My thought was perhaps I was not providing enough current, so I used two 15 ohm resistors in parallel to get 7.5 ohms.
This seemed to help as I was able to get a few to provide good light, but several can still not be used.
In all cases, when I quickly use a straight 5V supply, each and every module lights great - I only verify light and shut off asap.
I have tried to get clarification regarding the way the working current is listed: 280<mA @ 3V. So, without getting feedback from the seller, I am looking for some guidance.
Would the 280mA be a minimum required for operation?
Is there a typical range that laser modules have with regard to current?
Is it a tradeoff between brightness and module life?
I realize every module will not be the exact same, so am I stuck with trying each one or is there some way to use my meter to determine the units that seem to require more than 280mA?
Thanks