Circuits & Schematics Supply

You can use the circuit in Figure 1 to monitor the rotating speed of a dc fan motor and sound an alarm if the motor stalls. One potential application of the circuit is monitoring the CPU-fan speed in a PC in which overheating the CPU can ruin the ...

The conventional way to produce dual (positive and negative) outputs from a single positive input is to use a transformer. Although such designs are relatively simple, the transformer inherently introduces the problem of size. It can be challenging ...

A 4- to 20-mA current loop consists of a power source and a current-measuring device at the control end and a field transmitter that senses process-variable information, such as temperature or pressure, and converts it to a current (Figure 1). Most ...

Today’s small electronic appliances, such as washers, dryers, and stoves, use switched-mode power supplies to replace bulky, heavy, linear-power supplies. The engineer testing these power supplies, which range in current from 50 mA to 1 A, ...

As Moore's Law plunges us into the realm of multigigahertz processors and PCs with gigabytes of RAM, engineers face the task of removing the heat that these state-of-the-art components produce. Cooling such systems poses a dilemma. If you ...

One of the effective passive means you can use to suppress the ringing and clamp the overvoltages caused by the leakage energy in a flyback transformer is to implement a recuperating winding bifilar with the primary winding. This is the same ...

Some voltage references can be used as shunt regulators, either by tying V IN and V OUT together or by leaving V IN open. These devices are limited to low currents, however, with a typical limit of around 10 mA. Standard Zener diodes serve the same ...

A simple circuit monitors the elapsed time over which a line-connected ac load energizes (Figure 1). You can then access the elapsed-time count over a standard one-wire protocol. When you energize the ac load, the optoisolator provides pulses at ...

Synchronous buck regulators offer high efficiency and are popular in applications in which available input voltages are 12 V or less. However, as input voltage approaches 100 V, wide-range-regulator design becomes more difficult, and the choice of ...

Environmental systems that precipitate dust and carbon particles frequently use high-voltage dc power supplies. However, failure of high-voltage components caused by a change in their properties over time can create a large drop in voltage that ...