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.
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.