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Design Tips
Current
Dr. Ray Ridley, President, Ridley Engineering
Dr. Ray Ridley, President, Ridley Engineering
There have been many dramatic changes in power supply development over the last 20 years, but loop gain measurements remain the key to rugged and aggressive system performance. Understanding how to read a loop gain is important.
Loop gain measurements in modern systems
Quite
Dr. Ray Ridley, Ridley Engineering
Dr. Ray Ridley, Ridley Engineering
In this third article about power supply failures, the magnetics are examined for their contribution to the failure rate. These are usually the least understood of all components, and poor magnetics design can lead to many different failure mechanisms in power supplies.
Power
Dr. Ray Ridley, President, Ridley Engineering
Dr. Ray Ridley, President, Ridley Engineering
In this second article about power supply failures, the capacitors are examined for their contribution to the failure rate. The causes of failure for different types of capacitors are discussed. In the last part of this article, the question was asked of group members “Why do power supplies fail?” and the
Dr. Ray Ridley, President, Ridley Engineering
Dr. Ray Ridley, President, Ridley Engineering
We here at Ridley Engineering recently conducted a survey with a group of almost 3,000 active power supply design engineers to discover the various reasons and circumstances they have encountered power supplies that failed. The experiences the engineers shared with us were very enlightening, and this article
Dr. Ray Ridley, Ridley Engineering
Dr. Ray Ridley, Ridley Engineering
Point-of-load converters commonly use multilayer ceramic capacitors instead of electrolytic capacitors. The effect of this change is strongly felt in the bulk storage capacitor value, and can lead to unexpected variations in control measurements. Instability can result if input filter capacitors become too small.
Input
Dr. Ray Ridley, Ridley Engineering
Ray Ridley, Ridley Engineering
There has always been a debate about how essential it is to measure the loop of a switching power supply. Some power designers have always resisted this part of development and design validation, claiming they are able to tune a loop properly through step-load testing [1]. While this may have worked with low
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Figure 1: Buck Switching Cell and Circuit Placement
Dr. Ray Ridley, President, Ridley Engineering
All power electronics circuits with devices which rapidly turn on and turn off will exhibit voltage ringing when currents are interrupted or initiated. For transformer-isolated designs, the leakage
Click image to enlarge
Figure 1: PWM switches and the three equivalent circuits used for different types of analysis
Dr. Ray Ridley, President, Ridley Engineering
As mentioned in the last article of this series [1], Dr. Vatché Vorpérian developed the PWM switch model in 1986, which replaced the need for state-space averaging and greatly simplified the
Click image to enlarge
Figure 1: PWM switches needed to create a switching power supply. The diode can also be a synchronous rectifier if desired.
Dr. Ray Ridley, Ridley Engineering
Soon after switching power supplies were implemented in industry in the 60s and 70s, it became apparent that they had unique issues with control that defied normal circuit analysis. This gave rise
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Figure 1: Schematic of the flyback converter with AP300 connections for measuring the control-to-output transfer functions.
Dr. Ray Ridley, President, Ridley Engineering
This article is the fifth of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. With full input voltage and full load applied, the control-to-output
Ray Ridley of Ridley Engineering
In this video, Ray Ridley of Ridley Engineering describes his company's services
Ray Ridley of Ridley Engineering
In this introductory video on switching power supply design, Dr. Ridley
In this third part of a series of videos on frequency response analysis,
Dr. Ray Ridley, President, Ridley Engineering
Dr. Ray Ridley, Ridley Engineering
This article is the fourth of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. The power transformer is added to the circuit, and the current sensing and snubbers are designed to operate at full power without excessive stress on the components.
Power
Alix Paultre, Editorial Director, PSD
Alix Paultre, Editorial Director of Power Systems Design, and Dr. Ray Ridley
Click image to enlarge
Figure 1: Input line voltage POWER 4-5-6 simulation, showing rectified voltage on a 10 ï½F input capacitor.
Dr. Ray Ridley, President, Ridley Engineering
This article is the third of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. The input filter rectifier is simulated to find the design
In this video, Dr. Ridley presents the agenda for this unique power supply
Ray Ridley of Ridley Engineering
In this second part of a series of videos on frequency response analysis,
Ray Ridley of Ridley Engineering
In this video, the first part of a series of videos on frequency response
Click image to enlarge
Figure 1: Full schematic of a flyback converter.
Dr. Ray Ridley, Managing Director, Ridley Engineering
This article is the second of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. The second part of the series begins testing on the bias
Figure 1: Full schematic of a flyback converter
Dr. Ray Ridley, Ridley Engineering
This article is the second of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. The second part of the series begins testing on the
Dr. Ray Ridley, President, Ridley Engineering
This article is the first of a series in which Dr. Ridley shows the steps involved in designing and building an offline flyback converter. The first part of the series presents the power supply architecture and schematic, including the control and bias circuits.
Flyback power converter
The
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Fig. 1: Power supply with input filter module. A damping network is used to control the output impedance peaking.
Dr. Ray Ridley, Managing Director, Ridley Engineering
In this article, Dr. Ridley continues the discussion of power supplies with input filters. He shows how the presence of a poorly-designed filter has a drastic effect on the loop gain of a voltage-mode
Dr. Ray Ridley, Managing Director, Ridley Engineering
In this article, Dr. Ridley continues the discussion of power supplies with input filters. He shows how the output impedance of the input filter is measured, and demonstrates the importance of
Click image to enlarge
Fig. 1: Power supply with input filter module
Dr. Ray Ridley, Managing Director, Ridley Engineering
In this article, Dr. Ridley continues the discussion of input impedance measurements, and shows the effect of properly locating all of the input filter components. Middlebrook's input filter stability
Dr. Ray Ridley Managing Director Ridley Engineering
In this third part of this series of articles, Dr. Ridley discusses the fourth important frequency-response measurement made during full characterization of a switching power supply. The closed-loop
Dr. Ray Ridley Managing Director Ridley Engineering
In this article, Dr. Ridley provides further insight into frequency response measurements of transformers and inductors using equipment that you probably already have in your laboratory. An improved
Dr. Ray Ridley, President, Ridley Engineering
In this article, Dr. Ridley describes how you can make frequency response measurements of transformers and inductors using equipment that you probably already have in your laboratory. This is
Dr. Ray Ridley, President, Ridley Engineering
In over 30 years of designing power supplies, I have written multiple computer programs to help design, simulate, and understand power supply operation. This has culminated in Release 9 of POWER
Dr. Ray Ridley, President, Ridley Engineering
Dr. Ridley shows how the intricate details of magnetics construction can have a major impact on the operation of a flyback converter. Flyback Transformer Primaries If you are designing
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