PWM SOLAR CHARGE CONTROLLER CIRCUIT DIAGRAM
This post explanis about the working of pulse width modulation solar charge controller .
INPUT PROTECTION - Built-in Blocking Diode to prevent SPV array rfrom reverse plarity and
(SPV SIDE) to prevent reverse flow of current from Battery
- Built-in MOV protection against HIGH VOLTAGE LIGHTNING during rainy season
CHARGING - MOSFET Based PWM Charging (microcontroller controlled)
- BOOST CHARGING till the battery voltage reached 14.5V
- ABSORPTION MODE to charge the battery for 100% energy storage
- CHG. ON when PV Volt goes up 10V-11V
CHARGING LED - LED Flash during boost nad LED constant during absorption
- LED OFF when charging is OFF or PV Volt below 10V
LOAD CONTROL - LOAD connector continous active in NORMAL during Day or Night
- LOAD OFF during lo-batt cut-off at 9.5V or 10V
- LOAD reconnect when battery voltage goes up 12.5V or above
CIRCUITRY - Microcontroller based electronics
- MOSFET based load control switch and charging switch
- PWM charging for 100% energy storage compare to ON / OFF type charge controller
The hole circuit was powered by the battery follwed by the 7805 voltage regulatro.
At first the charge controller will wait the solar panel voltage to reach set point of 11volts ,when their is sufficent sunlight the solar panel voltage will reaches the set point voltage .Then the microcontroller will starts sending pulse width modulation signals to the mosfet in order to charge the battery ,when the solar panel voltage was below the set point voltage ,this pwm signals will not send by microcontroller to mosfet .
Then next the micro controller will check the battery voltage ,if the battery voltage was below 13.8v volts then the battery will be charged in boost mode ,that mean the battery will be charged with maximum amperage ,this boost mode of charging will be done by sending pulse width modulation signals with 95% duty cycle .
when the battery voltage reaches above 13.8 the charging mode will turn as absorption mode from boost mode ,this was done by changeing the duty cycle to 10% from 95 %.this absorption mode will keep the battery fully charged .