Circuits & Schematics Power

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 ...

Thanks to a combination of low initial cost and low on-resistance, a conventional electromechanical relay often makes sense for switching large amounts of load current on and off and when proportional control of the load's current or voltage is ...

Three-phase controlled rectifiers and inverters, matrix cycloconverters, and cascaded power stages typically comprise large numbers of power transistors, each with its own driver circuit. The circuit in Figure 1 drives a capacitive-input power ...

With their excellent isolation and reliability, gate-drive transformers (GDTs) are commonly used for driving half-bridge power circuits. However, they pose challenges when you want to have both switches off for an extended period. This application ...

High efficiency and, hence, low loss is a usual design goal for a PWM circuit. Figure 1 shows one of several channels of low-loss PWM control for hydraulic valves used in heavy industrial machinery. These valves usually have dc resistance of ...

In the circuit of Figure 1, assume that a brush-type dc motor must drive a load back and forth between two endpoints on a lead screw. Optical sensors determine end of travel, and an SPDT switch selects to which end to send the load. The sensors ...

A simple high-voltage MOSFET inverter solves the problem of driving a high-side MOSFET, using a low-voltage transistor, Q 1 , and a special arrangement involving D 6 (Figure 1). This inverter is much faster than those that optocouplers drive, so ...

The residual-current circuit breaker in Figure 1 continuously monitors the supply lines for any leakage current and immediately disconnects the supply if necessary. Load-supply wires, both live and neutral, pass through the magnetic core of the ...

P-channel MOSFETs can simplify designs when you use them as high-side switches on circuits with voltages exceeding 100 V dc. When driving a MOSFET, you must rapidly charge and discharge the input capacitance between its gate and its source to ...

Electronic Design In this Idea for Design, using a comparator-based switch-mode driver circuit of a solenoid improves efficiency by tailoring the drive to the pull-in versus hold-mode current requirements. Several years ago, Paul Rako, in ...