Precision Photodiode Comparator
This photodiode signal conditioning circuit is sensitive to light signal, suitable for interfacing digital serial signal. The biasing of the LM111 noninverting input is matched to the diode’s dark...
View ArticleInfrared (IR) Proximity Detector
This is infrared (IR) proximity detector circuit. A matched infrared emitter and detector pair is used in this circuit. The voltage controlled oscillator section of the LM567 tone detector IC is used...
View ArticleLogarithmic Light (Photodiode) Sensor Signal Conditioner
There are many measurement system that would be more suitable if we use logarithmic scale, especially when we try to mimics human sensory response. Most physical phenomenon that sensible to human’s...
View ArticleFive-Decade Dynamic Light-Level Meter
This is a Portable light-level meter circuit with five-decade dynamic range. This uses a single cell battery as the power supply. To calibrate this circuit, use an appropriate illumination, then...
View ArticleLight Level Droplets Detector
This is a circuit of Low-Light Level Drop Detector. This circuit utilize self-biasing configuration to detect small changes in light level. This circuit usually used in monitoring very low droplets...
View ArticleRelay Circuit Detects Light Change
Configured with capacitive coupling (by inserting a small cap between photo-transistor and bipolar transistor), this relay circuit will respond only to rapid changes in light while ignoring normal...
View ArticleFlash-Triggered Pulse Stretcher Using Classic Monostable Circuit
This is a flash triggered (photo-driven) circuit which produce a pulse with constant predetermined wide. This circuit can be used to control any device which is required to be synchronized with optical...
View Article
