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PIC16F1509 Solar Powered LED Security Lamp (Proof of Concept)

Design Highlights:

DC/DC Buck/Boost Power Supply
  • ~80% Efficiency @ 500mA charging current
  • 9 VDC – 25 VDC Input (compatible with 30-36 cell panels)
  • 6.8 VDC – 7.2 VDC @ 500mA DC Output for Battery Charging
  • 9 VDC – 24 VDC @ 350mA DC Output for LED Driving
PIC16F1509 Solar LED Lamp

Click image to enlarge

PIC16F1509 Controlled Topology

  • Core Independent Peripheral Integration
    • Numerically Controlled Oscillator (NCO)
    • 10-bit Analog to Digital Converter (ADC)
  • Maximum Power Point Tracking (MPPT) Solar Charging to Battery
  • Night sensing via solar panel
  • (2u) MCP6V02 OpAmp for current shunt amplification and motion sensing via Passive Infrared (PIR) sensor
  • MCP1790 High Voltage Regulator Boost LED Driver.

Theory of Operation

This proof of concept design is a solar DC/DC buck/boost power supply for battery charging and LED drive.

The design consists of 3 primary functions controlled by the PIC16F1509: buck solar powered battery charger, boost LED driver, and PIR sensor conditioning circuit. The switching is controlled using a fixed on-time, variable frequency signal generated by the NCO. The higher the frequency - the higher the duty cycle.

During daytime – the solar panel provides power, PIR motion detection is deactivated and only MPPT battery charging is active. During nighttime – motion detection is active and if triggered will start the LED driver for a specified time.

Theory of Operation

Click image to enlarge

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Products
Documents
Software
Development Tools

The software in this section is subject to the U.S. Export Administration Regulations and other U.S. law, and may not be exported or re-exported to certain countries or to persons or entities prohibited from receiving U.S. exports (including Denied Parties, entities on the Bureau of Export Administration Entity List, and Specially Designated Nationals).

Application Notes

Document Number Title
AN1138 A Digital Constant Current Power LED Driver
AN1050 A Technique to Increase the Frequency Resolution of PICmicro MCU PWM Modules
AN239 Bit Banged LIN Slave Node for PIC16 & PIC18
AN874 Buck Configuration High-Power LED Driver
AN1476 Combining the CLC and NCO to Implement a High Resolution PWM
AN1487 DALI Control Gear
AN980 Designing a Boost-Switching Regulator with the MCP1650
AN1035 Designing with HV Microcontrollers
AN1465 Digitally Addressable Lighting Interface (DALI) Communication
TB094 Dimming AC Incandescent Lamps Using A PIC10F200
AN1261 Dimming Power LEDs Using a SEPIC Converter and MCP1631 PIC Attach PWM Controller
AN948 Efficiently Powering Nine White LEDs with the MCP1650
AN1427 High Efficiency Solutions for Portable LED Lighting
AN1211 Maximum Power Solar Converter
AN1271 Offline Power Converter for High-Brightness LEDs Using the PIC16HV785 Microcontroller
AN1074 Software PWM Generation for LED Dimming and RGB Color Applications
AN1074-Setup Software PWM Generation for LED Dimming and RGB Color Applications
AN954 Transformerless Power Supplies: Resistive and Capacitive
AN-H48 HV9910B: Buck-based LED Driver
AN-H50 HV9910B: Constant, Off-time, Buck-based LED Driver
AN-H64 Compatibility and Functional Differences between the HV9961 and HV9910B LED Drivers
DN-H02 Isolated Constant Power Converter Using the HV9922
DN-H03 Alternate Use of the HV9922 as an Off-line, Non-isolated, 50 to 100 mA Auxiliary Power Supply
AN-H51 Designing a Boost-Buck converter with the HV9930
AN-H58 Improving the Efficiency of a HV9930/AT9933 Boost-Buck Converter

The software in this section is subject to the U.S. Export Administration Regulations and other U.S. law, and may not be exported or re-exported to certain countries or to persons or entities prohibited from receiving U.S. exports (including Denied Parties, entities on the Bureau of Export Administration Entity List, and Specially Designated Nationals).

Software

Title Document Type
DALI Code Library and Demonstration Code Software
DMX512A Code Library and Demonstration Code Software
Lighting Communications Development Platform Highlights & Demonstration Overview Collateral
Lighting Communications Development Platform Schematics Software
Lighting Communications Development Platform Users Guide Collateral
MiWi™ Wireless Networking Protocol to WiFi® Gateway DemonstrationKit (DM182018) Software
MiWi™ Wireless Networking Protocol to WiFi® Gateway Lighting Demonstration Code Software
PIC12F752 AC/DC LED Driver Demonstration Code Software
PIC12F752 AC/DC LED Driver Schematics Software
PIC16F1508 DALI Dimmable Fluorescent Ballast Demonstration Code Software
PIC16F1508 DALI Dimmable Fluorescent Ballast Schematics Software
PIC16F1509 Solar Powered LED Security Lamp Demonstration Code Software
PIC16F1509 Solar Powered LED Security Lamp Schematics Software
PIC16F1788 Wireless DC/DC LED Driver Demonstration Code Software
PIC16F1788 Wireless DC/DC LED Driver Schematics Software
PIC16F1947 Lighting Control Console DALI Demonstration Code (coming soon) Software
PIC16F1947 Lighting Control Console DMX512 Demonstration Code Software
PIC16F1947 Lighting Control Console Schematics Software
Stand-Alone RGBW Demonstration Code Software

Select:

Transitions between day and night modes are based on solar panel voltage, with minimal loading for current testing.

Regulation Algorithms

Solar Maximum Power Point Tracking (MPPT) is used for charging the battery efficiently. The implemented MPPT algorithm is Perturb & Observe using a proportional loop to modify the panel operating voltage. Battery charging is done using a proper 3-stage CC/CV lead-acid charging algorithm with floating charge. Charge termination is triggered by either minimum current, flat current or a timer. LED current regulation is done by a proportional loop operating on the NCO frequency.

Contact your local sales representative to see a working demonstration of the Solar LED Driver.

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