IsaacT
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- Joined
- Aug 25, 2010
- Messages
- 5,947
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Hey guys,
I don't know enough about LED's to know what needs to be done. I am planning a build with an LED indicator light and I havent been able to find how people are driving the LED's. The build will be a single cell 488nm laser, so I guess the input voltage will be 3.7V. The DTR 488 module/driver combo states 2.5V-6V 1A+. A random 5mm LED I found shows a typical forward voltage of 2.0V and current of 20mA. I am assuming that forward voltage means the amount of voltage lost from one side of the component to the other.
1. To avoid issues with losing the necessary voltage across the Laser Diode, as 3.7V - 2.0V is only 1.7V, well below the stated input requirement, should I run the LED and the Laser Diode in Parallel to supply both with a voltage input of 3.7V?
1a. Alternatively, should I use two batteries for a total of 7.4V coming in to the circuit and have the LED in series with the Laser Diode such that the 7.4V - 2.0V will yield 5.4V which also fits into the stated input requirements for potentially longer runtimes?
-Caveat to this is would this be playing a dangerous game? I assume if the LED emitter dies, the component would no longer be soaking up that extra voltage and would give too much voltage to the Laser driver. Which, in turn, may kill the diode?
2. Do I need something to drive the LED emitter similar to how we use laser drivers to limit the current coming in?
Tentatively this is planned for a modified laser66 host so space concerns are very real.
Thank you for any advice you can provide!
-IsaacT
I don't know enough about LED's to know what needs to be done. I am planning a build with an LED indicator light and I havent been able to find how people are driving the LED's. The build will be a single cell 488nm laser, so I guess the input voltage will be 3.7V. The DTR 488 module/driver combo states 2.5V-6V 1A+. A random 5mm LED I found shows a typical forward voltage of 2.0V and current of 20mA. I am assuming that forward voltage means the amount of voltage lost from one side of the component to the other.
1. To avoid issues with losing the necessary voltage across the Laser Diode, as 3.7V - 2.0V is only 1.7V, well below the stated input requirement, should I run the LED and the Laser Diode in Parallel to supply both with a voltage input of 3.7V?
1a. Alternatively, should I use two batteries for a total of 7.4V coming in to the circuit and have the LED in series with the Laser Diode such that the 7.4V - 2.0V will yield 5.4V which also fits into the stated input requirements for potentially longer runtimes?
-Caveat to this is would this be playing a dangerous game? I assume if the LED emitter dies, the component would no longer be soaking up that extra voltage and would give too much voltage to the Laser driver. Which, in turn, may kill the diode?
2. Do I need something to drive the LED emitter similar to how we use laser drivers to limit the current coming in?
Tentatively this is planned for a modified laser66 host so space concerns are very real.
Thank you for any advice you can provide!
-IsaacT