You guys can correct me if I'm wrong..
Here's the explanation on how to select # of diodes based on the diode breakdown voltage:
I noticed that if you look at a datasheet of the laser diode, it will tell you operational voltage. This is the voltage value is the target value you want to build up your diodes in series. For example if your IR LD is 2.1V Operation Voltage, you want to try to get 3 diodes (with breakdown voltage of 0.7V) to get to that value of 2.1V. Another example, if you have breakdown voltage of 0.5V diodes, then you would need 4 of them.
If you don't have the datasheet then the rule of thumb is 3 diodes for IR, 4 diodes for red, and 6 diodes for BR. This assumes the breakdown voltage of the diodes are 0.7. Do your math accordingly.
The 1 ohm resistor in series is for measuring the current going through the path. Voltage = Current x Resistance.. and since you use Resistance = 1 ohm, the voltage measured across the resistor would be the current (+/- % of error of resistor value)
Here's the explanation on how to select # of diodes based on the diode breakdown voltage:
I noticed that if you look at a datasheet of the laser diode, it will tell you operational voltage. This is the voltage value is the target value you want to build up your diodes in series. For example if your IR LD is 2.1V Operation Voltage, you want to try to get 3 diodes (with breakdown voltage of 0.7V) to get to that value of 2.1V. Another example, if you have breakdown voltage of 0.5V diodes, then you would need 4 of them.
If you don't have the datasheet then the rule of thumb is 3 diodes for IR, 4 diodes for red, and 6 diodes for BR. This assumes the breakdown voltage of the diodes are 0.7. Do your math accordingly.
The 1 ohm resistor in series is for measuring the current going through the path. Voltage = Current x Resistance.. and since you use Resistance = 1 ohm, the voltage measured across the resistor would be the current (+/- % of error of resistor value)
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