Circuits & Schematics - Measurement - 9

Sensors that detect and track small metallic objects are handy gadgets, whether used to route workpieces on an assembly line or comb a beach for “treasures” lost in the sand. A typical sensor design consists of an inductor integrated ...

LVDTs (linear variable differential transformers) are electromechanical measuring devices that convert the position of a magnetic core into electrical signals. You generate these signals via excitation on the primary side. The results on the ...

Almost all precision voltage-to-frequency converters (V-F) utilize charge pump based feedback for stability. These schemes rely on a capacitor for stability. A great deal of effort towards this approach has resulted in high performance V-F ...

The accurate, high-side, current-sense circuit in Figure 1 does not use a dedicated, isolated supply voltage, as some schemes do. Only the selected transistors limit the common-mode range. The circuit measures the voltage across a small ...

Powering portable telemetry systems for long-term monitoring presents interesting design challenges. Batteries are unsuitable for certain critical applications, and, in these circumstances, designers typically use wireless inductive links to ...

Laser diodes can destroy themselves in a few nanoseconds, so testing the response and stability of a feedback-stabilized laser-diode driver can be expensive. The simulator circuit in Figure 1 shows a typical laser-diode package, which contains not ...

Besides its mind-boggling simplicity and programmable resolution, the chief attribute of the Shannon decoder DAC (SD) is speed ( Ref. 1 ), converting a serial n-bit digital stream into an analog signal in just nT seconds where T = 1 bit time. Of ...

It’s just an unavoidable fact: electronic components’ parameters drift with temperature. Even the most stable voltage references, op amps, crystal oscillators, etc., have non-zero temperature coefficients. These effects can be mitigated ...

Filter, audio, and RF-communications testing often require a random noise source. Figure 1’s circuit provides an RMS-amplitude regulated noise source with selectable bandwidth. RMS output is 300 mV with a 1 kHz to 5 MHz bandwidth, selectable ...

Figure 1 is a “charge pump” type V/F converter specifically designed to run from a 3.3 V rail. A 0 V to 2 V input produces a corresponding 0 kHz to 3 kHz output with linearity inside 0.05%. To understand how the circuit works assume ...