Download CPC 1822 Specifications - San Jose State University

San José State University
College of Engineering/Electrical Engineering
EE174: Analog Peripheral for Embedded Systems
Section 01, Spring 2016
LAB4 Energy Harvesting (EH)
Goals:
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The goal of the experiment is to generate power from a miniature photo cell.
Understand basic principle and knowledge of EH photovoltaic transducer.
Required Equipment:
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CPC1822 miniature photo cell
Breadboard and Components
References:
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http://www.farnell.com/datasheets/1681419.pdf
DS-CPC1822-R03 www.ixysic.com
www.spacegrant.hawaii.edu/reports/26_SP12/TMartinez_S12.pdf
CPC 1822 Specifications:
The CPC1822 is a monolithic photovoltaic string of solar cells with switching circuitry. When
operating in sunlight or a bright artificial light environment the optical energy will activate the
cell array and generate a voltage at the output. The solar cells are capable of generating a
floating source voltage and current sufficient to drive and power CMOS ICs, logic gates and/or
provide “trickle charge” for battery applications.
CPC 1822 Circuit:
To ensure that enough current is available to drive an output (LED), a voltage follower or buffer was
included in the circuit setup. The buffer copies the voltage reading from the sensor and forces
current to the copied output voltage. To improve noise at the output, a RC low-pass filter is
implemented in conjunction with an op-amp, capacitor and resistor. The capacitor would have a
fixed capacitance but a trim-pot resistor would be used for variable resistance allowing for tuning
the filter. The overall circuit would consist of a buffer and low-pass filter. A schematic of the circuit
is shown below.
Circuit 1.
Another circuit to drive an output load (LED).
Circuit 2.
Required Task:
1. Measure the output of the photo cell at no load. Plot the data.
Completely Dark
In door no light
In door with light
Bright sun or high
density lamp
2. Circuit 1: Verify if single photo cell has sufficient current to power the load. Record
the voltage range.
3. Capture the output voltages and record values of resistor and capacitor used in
circuit.
4. Circuit 2: Repeat step 2. and 3.
5. Measure voltage across Rb to verify the current.
6. Implement two photo cell in series and in parallel and repeat the results.
7. Create your own application for extra credit.