Articles - Measurement - 3

Many power-supply designs rely on accurately sensing the voltage across a current-sense element. Multiphase regulators use the sense voltage to force current sharing among phases, and single-phase regulators to control the current-limit setpoint. ...

A recent Design Idea ( Ref. 1 ) presents a circuit to measure an airflow rate up to 2000 fpm using two transistors in a Darlington configuration. One transistor works as a self-heated thermal sensor and the other one compensates for ambient ...

One of our technicians recently asked for help determining the value of an SMT inductor. It was unmarked, and was many turns of very fine wire on a ferrite core. The resistance measured 26 Ω, which for some reason gave our ancient LCR bridge ...

The 8-bit resolution of a peripheral DAC (such as the ATtiny family, for instance) is often insufficient. Let’s see how the problem can be solved using on-chip resources. The circuit in Figure 1 shows a method to improve the resolution of a ...

One of the first problems a capacitive-sensor analog designer must face is the low-frequency cutoff. Theoretically, you must fulfill just one simple requirement: a sufficiently large input resistance of the preamplifier's first stage. In ...

A bi-directional current source for a grounded load will always have some complication in its construction. The improved Howland Current Pump as shown in Figure 1 is the most frequent choice for this function. The Howland requires carefully matched ...

Despite the increasing availability and declining cost of on-chip analog peripherals, the humble PWM DAC retains its appeal as a “free” DAC [ 1 ] that can repurpose an uncommitted DIO pin and counter/timer module, add a simple low pass ...

The circuit in this Design Idea was originally designed to detect damaged conveyor belts in the mining industry. Thin coils are embedded in the conveyor belt. If the belt suffers damage, it stretches at the affected location, causing one or more ...

Trying to shield ambient light from your photo circuit is not a trivial task. You would think that you could just cover your circuit with your hands, but that is not a solution: Pulse oximeters depend on the translucency of flesh. Covering the ...

This article will describe how Bode plots can be used as a tool to quickly assess if your power supply design will meet the requirements for dynamic control behavior. Power supplies normally maintain a fixed output voltage via a control loop. This ...