Circuits & Schematics Power - 16

Horst Koelzow, Calgary, Alberta EDN Many single-voltage power supplies consist of a transformer, a rectifier, and a filter capacitor, as shown in Figure 1. This circuit is relatively inexpensive and easy to build but supplies only a single voltage. ...

Nora Jacalan Esteves, Technor Semiconductor LLC EDN With only a few additional components, you can use a highly efficient step-down dc/dc converter to create a constant-current, multiple-channel LED driver. It is relatively easy to drive a ...

Richard Oliver, Lowell Observatory, Flagstaff, AZ- June 4, 2012 Solenoid loads generally exhibit large hysteresis. Application of the rated voltage actuates these loads. Once they are in position, however, you can use a significantly lower voltage ...

By Jacques Audet Brossard, QC, Canada Electronic Design Europe Designers commonly use varistors in voltage limiters targeting short-duration voltage spikes typically lasting less than 10 ms. But for protection against longduration overvoltages, ...

Steven Lau, Ronald Moradkhan, Maxim Integrated Products When measuring the efficiency and load regulation of linear and switching voltage regulators, it is helpful to have access to an isolated, regulated current source to drive load under test ...

Peter Demchenko Zero-crossing detectors synchronize the turn-on time of an ac switch with the zero-voltage condition and are often used to reduce in-rush current and commutation noise. The zero-crossing detectors described here control triacs, but ...

Jeff Wilson, STMicroelectronics Use two diodes and two capacitors to generate a negative voltage. This Design Idea describes a circuit employing a small microcontroller-based sensor module with only three connections: 5V dc, an RS-232 transmit-data ...

Gunther Kraut Logic 1, logic 0, and high-Z make for three possible states: forward, reverse, and off Independently switching two loads, such as relays, usually requires two microcontroller-I/O ports. Two ports let you control the loads so that you ...

Kevin Tompsett, Analog Devices EDN Inexpensive boost regulators with on-chip FET power switches work well for low-voltage boost converters, SEPICs (single-ended primary-inductance converters), and flyback converters. For higher voltages, designers ...

By Jim Wilson Allied Healthcare Products Electronic Design Europe Most microcontrollers have a pulse-width modulator (PWM) output that can effectively drive variable output loads such as proportional solenoid valves, motors, or light dimmers. You ...