Constructing a custom fitness tracker or gesture recognition device requires an accelerometer, specifically the ADXL335. This compact sensor detects acceleration through a suspended mass that shifts during movement. The setup involves connecting capacitors and operational amplifiers to process the sensor's output. The article outlines the steps to create a step counter by filtering and amplifying the signal, resulting in clock pulses for counting. A video demonstration showcases the circuit in action.
Light flicker in LED lighting arises from the conversion of alternating current to direct current, leading to periodic fluctuations in brightness. These fluctuations can affect human perception and cause fatigue, especially at frequencies of 100–120 Hz. Acceptable flicker percentages, regulated by standards, should remain below 9.6% for general use and 4% in sensitive environments. Understanding flicker metrics and using high-quality drivers can help mitigate these effects effectively.
Create a touch sensor-controlled LED lamp with dimming and rechargeable features. This guide provides step-by-step instructions for building it yourself, using easily accessible components.
LED drivers are classified by output regulation into constant current, constant voltage, and constant power types. Constant current drivers keep a fixed current to stabilize brightness in series-connected LEDs, while constant voltage drivers suit parallel LED modules but incur energy losses through resistors. Constant power drivers adjust the current to maintain steady power, offering flexibility with LED suppliers, though at a higher cost.
Let's assemble a completely analog PWM LED brightness controller using four operational amplifiers and figure out why PWM is needed and what it is.
