EE40 Final Project
Light Detection Circuit
Project Summary
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Light-sensing circuit; When there is no light
shining on the detection part of the circuit, the
green LED flashes. At the presence of light, the
red LED flashes instead of the green one.
Possible application:…..
Possible improvements:………
Supply Circuit
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Purpose: powers the
circuit components by
generating two different
voltages from a single
input voltage
Input: 9V
Output: 4.5V and 9V
Comments: The op-amp
act as a voltage follower
that outputs 4.5V.
9V
4.5 V
Square Wave Oscillator
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Purpose: Generates 0-9V
square wave signal that
makes the LED’s flash.
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Input: 4.5V and 9V
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Output: 0 or 9V
4.5 V
9V
Light Detection
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Purpose: detects light
4.5 V
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Input: 4.5V
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Output: 0 or 4.5V
Comparator
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Purpose: compares the output
of the light detector with the
threshold
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Input: 4.5V and 9V
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Output: 0 or 9V
4.5 V
9V
AND Gate
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Purpose: To control the
flashing of the red LED
based on the MOSFET’s
drain
9V
Bonus circuit examples: VU
Meter
500k