Constant Current Supply for High Power Laser Diodes.

Super Simple Laser Diode and TEC Driver.

EU38 Low Cost Constant Current Laser Diode Driver.

Laser Diode Driver from Green Laser Pointer 4 (GLP-LD4).

Laser Diode Driver from Green Laser Pointer 3 (GLP-LD3).

Laser Diode Driver from Green Laser Pointer 2 (GLP-LD2).

Laser Diode Driver from Green Laser Pointer 1 (GLP-LD1).

Laser Diode Driver from Red Laser Module 1 (RLM-LD1).

Laser Diode Driver from IR Laser Module 1 (ILM-LD1).

Laser Diode Driver from Cheap Red Laser Pointer 5 (LP-LD5).

Laser Diode Driver from Cheap Red Laser Pointer 4 (LP-LD4).

Laser Diode Driver from Cheap Red Laser Pointer 3 (LP-LD3).

Laser Diode Driver from Cheap Red Laser Pointer 2 (LP-LD2).

Laser Diode Driver from Cheap Red Laser Pointer 1 (LP-LD1).

Viacheslav's Laser Diode Driver (VS-LD1).

Modification of SG-LD1 for Common Cathode LD/PD (SG-LD2).

Toshiba Discrete Laser Diode Power Supply (TO-LD1).

Schematics of Laser Diode Power Supplies.

Using an External Photodiode for Power Control.

Response Time of Laser Diode and Monitor Photodiode.

Variations in Laser Diode Monitor Photodiode Current Sensitivity.

Comments on Driver Education for Laser Diode Driver Designers.

More on Laser Diode Characteristics and Drivers.

Comments on Some Commercial Drivers and Detectors.

Caution About Cheap Laser Diode Drivers.

Integrated Circuits for Driving Laser Diodes.

Blinking Laser Pointer or Diode Laser Module?.

Powering a Laser Pointer From an External Source.

Substituting Batteries in Laser Pointers.

Laser Pointer with a Resistor for a Regulator.

Laser Pointers and Diode Laser Modules - The Low Stress Approach.Alternatives - Diode Laser Modules, Laser Pointers.Back to Sam's Laser FAQ Table of Contents.ĭiode Laser Power Supplies Sub-Table of Contents.Although the LM317 is rated for 1,5 Ampere, I wouldn't recommend it for applications that need more than 1 Amperes, because it gets very, VERY hot.Sam's Laser FAQ - Diode Laser Power Supplies The closest E12 value is 1,8 ohms, the output will be 694mA the resistor must be at least 1W in both calculations.

If you use 3W LEDs, which has a current consumption of 700mA, the calculation should be: 1,25 divided by 0,7 makes 1,78. However you can't see any difference in the light output. The closest E12 value is 3,9 ohms, it will give you a constant current of 321mA. So if the resistor is 3,57, constant current will be 350mA. so if you want to connect one or more luxeon 1W LEDs, which has a power consumption of 350mA, the calculation should look like this: 1,25 (the constant reference voltage of the LM317) divided by 0,350 (the LEDs power consumption) makes 3,57. Ohm's law says that U/I=R, which means that Voltage divided by Ampere makes resistance. The LM317 regulator gives out a constant voltage of 1,25 volts between ADJ and Vout, so by adding a resistor between these two outputs, you'll get a constant current.

Lm317 laser circuit diagram