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New to the forum-Greetings from SWFL

diachi

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I am going back to school in January and need a place to “rest my brain”, so lasers are going to be my “mental relaxation”for at least the next two years.

Sounds like you need an RGB laser projector, a smoke machine, a good stereo and a some Pink Floyd albums! :beer:

Welcome!
 





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Dec 17, 2017
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I got the whole Pink Floyd thing set up already. I just need to have a laser projector and the smoke machine.

I was given a high powered red LED with heatsink to act as the load when setting the current of the driver. My DMM was in series, power side, with the circuit.
 
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diachi

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I was given a high powered red LED with heatsink to act as the load when setting the current of the driver. My DMM was in series, power side, with the circuit.

Please avoid double posting (two posts in a row in the same thread), it's frowned up here, at least when done in quick succession, waiting 24-48 hours is generally fine. You can use the "edit" button to update your previous post, or delete it and submit a new post containing the old post and the new information.

That works, however, you need to ensure that the forward voltage of the LED is close to the forward voltage of the laser diode you intend to use.

Typical laser diode driver test loads use several rectifier diodes and a current shunt in series for forward voltage matching and current measurement. A good test load will allow you to set the forward voltage by selecting the number of diodes in the circuit. To measure current you measure the voltage drop across the shunt resistor and use V=IR to calculate the current.

Here's an example of a 3A selectable test load. You can see the jumpers and pins used to set the forward voltage.
selectable_test_load.jpg
 
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Gazen

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Nov 13, 2017
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Welcome to LPF from a fellow newbie. Same thing happened to me, but unfortunately it already got my wallet.
:)
 




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