All articles tagged with #op amp
[Floydfish] has created a low noise instrumentation amplifier using a row of low-noise op-amps presented in parallel at the input, followed by a buffer and a set of filters for different output frequency ranges. This circuitry serves as a learning exercise for anyone interested in pushing low noise circuitry to the limit.
John Guy has designed a continuity tester that modulates the beeper's tone according to the resistance measured in the circuit, making it easier to track down a short circuit. The circuit is based on a single AD8534 quad op amp chip and features a voltage-controlled oscillator, a comparator with hysteresis, and a low-pass filter. The PCB design is easy to assemble and can be placed in a laser-cut acrylic case, turning it into a neat handheld instrument.