Circuits & Schematics Measurement

Some of the electrical signals we work with are said to be “floating” with respect to ground. A typical example might be a voltage drop over a shunt resistor in a power supply or a complex biomedical signal, such as an ECG. In such ...

To determine the specifications of a solar-generating plant, I needed to accurately measure the load current a product consumed. The product switched several internal devices on and off during an interval of several seconds. An ammeter showed that ...

You face a serious problem in using a slow ADC with a fast peak detector. The circuit in Figure 1 allows a slow ADC to measure a fast, sampled signal peak. The 100-MHz peak detector for ultrasonic-pulse sampling uses a fast MAX4231 amplifier. This ...

This Design Idea shows how to build a reliable, low-cost, and simple inductance tester. The basis for the tester is a Pierce buffered CMOS oscillator (Figure 1). Instead of using the usual quartz crystal, you connect the inductor under test. This ...

The inverters in a CMOS CD4069 can be used for both analog as well as digital applications. This Design Idea illustrates this by using all six inverters in a 4069 package to make a closed loop, duty-cycle-based capacitance meter with a full scale ...

The simple circuit in Figure 1, which can be powered with a 3.6 V nickel-cadmium rechargeable battery, lets you use an LED to detect light. The circuit consumes practically no quiescent power. Two LEDs act as photodiodes to detect and respond to ...

Large analog systems that present many loads to a voltage-reference source can often demand more current than a single reference IC can deliver. However, if the reference IC includes force and sense terminals, you can easily add a buffer to the ...

Certain current-sense amplifiers have to contend with frequent overvoltages. For example, a current-sense amplifier that monitors battery discharge currents in an automobile must withstand high-voltage load dump pulses produced when loads are ...

When processing signals from analog sensors, you frequently encounter wide variations in attenuation among communication channels or sensors. Or, you face situations in which several identical sensors within a supervised system return signals of ...

The advent of inexpensive standardized 16- and 24-bit audio I/O hardware for personal computers inspired a rush of oscilloscope simulating applications. Many of these “Sound Card Scopes” are quite capable, providing input scaling, ...