Circuits & Schematics - Measurement - 6

There are many applications where an ADC needs to process a small differential input signal in the presence of a large common-mode signal. Traditional instrumentation amplifiers (in-amps) are not commonly used in these applications, due to their ...

High speed and precision are not the only areas where special V-F circuits are needed. Figure 1 shows a circuit which runs from a single 1.5 V cell with only 125 µA current drain. The circuit uses an LT1017 dual micropower comparator in a ...

The gain temperature coefficient of conventional V-F circuits is affected by drift in the charge pumping capacitors. Although compensation schemes are employed to minimize the effect of this drift, another approach is required to get significantly ...

Manufacturers of optocouplers characterize their devices for CTR (current-transfer ratio), and an optocoupler’s data sheet will list its CTR ranges. Unfortunately, the CTR range may be too wide for some applications, requiring you to screen ...

Few methods for analog to digital conversion are more “mature” than the classic combination of a voltage-to-frequency converter (VFC) with a counter. VFC digitization is naturally integrating, so good noise rejection is inherent, as is ...

It’s interesting, useful, and fun that basic electronic topologies often turn out to have utility in multiple and surprisingly different applications. Figure 1 shows an example of such a circuit. It’s a charge pump voltage inverter ...

Battery-operated instrument benefited from auto-power shutdown A handheld, battery-operated “fiber finder” measures the light escaping from an optical fiber when clamped in a V-shaped block under slight pressure. A pair of photodiodes ...

Figure 1 shows two large-signal- measurement methods. The first uses a two-resistor voltage divider and an output buffer, and the second comprises an attenuating inverter and a high-value input resistor. Both of these approaches introduce ...

All thermal anemometers work by inferring air speed from measurements of thermal impedance (Z) between a heated sensor and the surrounding air: (1) where P is the power dissipated by the sensor and T is the temperature difference between the sensor ...

Several years ago we were developing a clamp-on photometer, a hand-held instrument that could be clamped onto a communications optical fiber to indicate the presence of light, its direction of travel, and the presence of combinations of ...