In a three-phase ac system, a power source with three wires delivers ac potentials of equal frequency and amplitudes with respect to a zero-potential wire, each shifted in phase by 120° from one wire to the next. Two possibilities exist for establishing a phase sequence...
Articles and news - 5
Phase-sequence indicator uses few passive components
Single IC forms precision triangular-wave generator
The linearity of triangular waveforms makes the triangular- wave generator useful in sweep circuits and test equipment. For example, switched-mode power supplies and induction motor-control circuits often include a triangular-wave oscillator as part of their PWM circuit...
Using a MOSFET as a thermostatic heater
The MOSFET is used as both a heater and a temperature sensor in a thermostatic circuit...
Simple fixture statically tests programmable-gain amplifiers
The advent of instrumentation amplifiers with digital gain switching offers obvious advantages, such as board-space saving, higher reliability because of fewer solder joints, and lower total cost...
AGC circuit uses an analog multiplier
In the AGC circuit, a 4-quadrant analog multiplier, an amplifier stage, an active, full-wave rectifier, and an integrator accomplish automatic gain control of VIN’s amplitude variations in the audio-frequency range...
LT1635 1A shunt charger
Most battery chargers comprise nothing more than a series-pass regulator with current limit. In solar-powered systems, you can’t count on sufficient headroom to keep a series regulator alive, so a shunt method is preferred...
Ultra-low distortion sinewave oscillator. Part 1
A sinewave is the simplest possible waveform, it is also one of the hardest to generate in pure form. Any impurity represents distortion, and that means added harmonics that make very low distortion measurements impossible...
Finely tune the hue of blue-light sources
When coach cars of long-range trains comprised compartments for six to eight passengers, the passengers could choose either “white” or deep blue light. The blue light helped passengers sleep, even when they were not in full darkness. The circuit lets you set a hue of blue light...
Accurately simulate an LED
Solid-state-lighting applications are quickly moving into the mainstream. Although they are more efficient, the LEDs that produce the low-cost light often require a complicated driver circuit. Testing the driver circuit using LEDs, although easy, yields only typical results...
Battery simulator has variable ESR response
You may lack experience and hardware when designing battery-operated products. The battery life of a product can depend more on the ESR (equivalent series resistance) than the terminal voltage...