Схемы - Измерения - 7

Stephen Woodward

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 ...

Stephen Woodward

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 ...

Glen Chenier

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 ...

Chau Tran Moshe Gerstenhaber

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 ...

Stephen Woodward

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 ...

Glen Chenier

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 ...

Stephen Woodward

Self-heated transistors used as thermal air flow sensors are a particular (obsessive?) interest of mine, and over the years I must have designed dozens of variations on this theme. Figure 1 illustrates one such topology seen here (Reference 1) ...

Stephen Woodward

Anemometers are an important category of environmental sensor. Articles about their design, data capture, and linearization have comprised topics featured in EDN Design Ideas, several quite recently. Less well covered, however, has been the topic ...