The scenario
Designing a simple smoke detector alarm circuit for a residential application. When smoke is detected, the sensor resistance drops, causing the comparator to output high and light the LED.
What is in this drawing
Read the decisions behind it.
01
Using a comparator with a pull-up resistor to drive the LED
02
Adjusting sensitivity via the reference voltage divider
Suitable for basic smoke alarm systems where a visual indicator is needed instead of or in addition to an audible one.
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