Circuits & Schematics Measurement

Although an analog moving-coil meter may lack the resolution and accuracy that a digital readout provides, a meter remains the display of choice for certain applications. A digital readout simply cannot provide information about a measurement's ...

A previous Design Idea describes an interesting and useful method for using a moving-coil analog meter to measure currents in the less-than-1A range ( Reference 1 ). The design offers considerable flexibility in the choice of meter-movement ...

This circuit was born from an application that required an input signal to be precisely clamped to less than 2.5 V, while operating on a 2.5 V supply (actually a reference) with a maximum output of 4 mA. Since the signal’s dynamic range is ...

A random-bit-sequence generator is basic equipment for prototyping and testing any data-transmission system. You use such a generator when measuring BER (bit-error rate) and pattern-dependent effects in a transmission system. Such effects can ...

A broadband source of white noise can be useful for measuring and testing communications equipment. The source in Figure 1 is simple and produces a large noise signal at its output terminals. The circuit comprises a zener diode and a few amplifying ...

The circuit in Figure 1 is useful when you need amplitude demodulation or an averaged absolute-value conversion. The circuit comprises two stages, the first of which, IC 1A , is a differential-output absolute-value converter. The second stage, IC ...

Most simple circuits you'll find for measuring reactive components cover only a limited range of component values. Here's a circuit built from a handful of inexpensive parts that will let you measure values of both capacitors and inductors ...

It can be helpful to rapidly and easily determine the polarity (npn or pnp) and function of a transistor. The pocket-transistor tester in Figure 1 is ideal for quickly testing without regard to such parameters as gain and frequency response. You ...

Also called the ThermoPen, the goal of this project was to create a portable thermometer usable for precise uses case. More particularly, is was created to inspect overheating electronic parts on PCB and for general troubleshooting. At my school, ...

This circuit increases the repeatability of noise test setups by providing reference points in the noise-vs.-frequency output generated by the network analyzer. It's based on Maxim MAX4475 , MAX427 , and MAX4101 op amps. Noise measurements can ...