Digital LED Dimmer With 2 Digit Display Using PIC Micro-Controller

Digital LED dimmer with 2 digit display, simple circuit using PIC16F1825  Micro-Controller and CAT4016 LED diver from www.onsemi.com .  LED intensity can set using two tact switches. The board provides TTL PWM 1-99% duty cycle out which required Mosfet/BJT transistor or LED driver on output for LED load. Frequency 250Hz.

  • Supply 4.5 to 5V DC
  • Range 01 to 99 Duty Cycle
  • On Board Two Switches for PWM
  • On Board Power LED

 

 

 

 

 

 

 

 

 

 

CONSTANT CURRENT LASER DIODE DRIVER CIRCUIT USING OP-AMP

CONSTANT CURRENT LASER DIODE DRIVER

The voltage controlled current circuit can be used to drive a constant current into a signal or pump laser diode. This simple linear driver provides a cleaner drive current into a laser diode then switching PWM drivers. The basic circuit is that of a Howland current pump with current buster transistor on output of a R-R CMOS OPA2350 op-amp. Laser diode current sensed by differentially measuring the voltage drop across a shunt resistor in series with the laser diode. the output current is controlled by the input voltage that may be from an analog voltage source or from a DAC. Scale factor is 1V input equals 1A output. The scale factor VIN/IOUT can be set to other values by choosing appropriate resistor values using the equation. VIN/IOUT=R2/R6 X R-Shunt & R2=R3, R5=R6.

constant-current-laser-diodde-driver-circuit

pcb-blk

pcb

Circuit Idea From TI Application

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