# Questions tagged [power-electronics]

Refers to the conversion of electric power by using solid state components such as semiconductors. Can also generally apply to the field of electrical engineering which works with power electronics.

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### Calculating the ESR of Capacitor

I try to calculate the ESR of a capacitor. I checked this datasheet: http://www.farnell.com/datasheets/2245214.pdf?_ga=2.167304311.817060034.1534770853-676261198.1531404202 I can see from the ...
417 views

### Clearance through pcb

I've become fairly familiar with the clearance and creepage requirements of UL/IEC/etc 60950, 60730 and derived/related standards. I've just realised, though, that they only refer to distances through ...
44 views

### How to determine Vds(on) and Vds(off) for switching loss calculation?

In the Infineon Application Note, two of the parameters they've used to calculate the switching loss of the MOSFET are Vds(on) and Vds(off). Is the Vds(off) the blocking voltage? Where do they obtain ...
35 views

### Switching load with changing polarity

From a bespoke board I'm receiving 18vdc that I need to switch. This 18vdc will usually be +18vdc but at times can be -18vdc. The load is .35A. The polarity is being changed via a H-Bridge and ...
89 views

### Is my IIR implementation (in C) correct for this difference equation?

I recently started developing a digital regulator for a DCM boost (Digital regulator for DCM Boost - How does it relate to duty cycle?) And I've implemented the difference the following controller in ...
81 views

### 2KW - 48V - 240v / 50Hz UPS - Unknown Topology

I am refurbishing a 2kw ups that a friend gave to me. It had failed and had been left in a shipping container on a site and the PCB had suffered some low level corrosion. The PCB is a 2 layer board, ...
78 views

### MOSFET pinchoff reduce current

I understand that in an n channel MOSFET as Vgs increases, electrons are attracted towards the gate forming an n channel. These electrons are responsible for the conduction of the MOSFET. As Vds ...
133 views

### How does a electropermanent magnet work?

Iām trying to wrap my head around electropermanent magnetism. I read this wonderful PhD Thesis by Ara Knaian as well as details the history of this concept as well as Kyle Gilpin, Ara Knaian, and ...
66 views

### Alternate uses for Gate Driver - Driving a Load without External IGBT or FET

What issues would one encounter by using a gate driver IC to directly drive a load instead of using it to drive transistors? For consideration would be the very affordable Infineon 2EDN752x series ...
29 views

### Three-phase rotary converter wiring questions

I am installing a 30 HP three-phase rotary converter on a 200 amp service in my home shop. I intend to run a CNC milling machine with a 15 HP motor. I am using 2 AWG wiring in 1" shielded conduit ...
100 views

### How to ground a flyback transformer?

I designed a 50,000 volt power supply, that I am having problems with on grounding the HV side of the output. The HV appears to be injecting HV into my logic sections through the ground, damaging the ...
74 views

### Generating +65 V (positive) and -65 V (negative) voltages from two 12 V batteries using cheap step-up converters?

I need to power a 300 W class D amplifier with positive and negative 65 V. As I'm a do-it-yourself guy, I didn't know about positive and negative voltage and ordered a bunch of these normal step-up ...
45 views

### TRIAC driver circuit behavior when switching low current loads

I'm doing a project that involves switching different kinds of loads (edit: by that I mean loads that go from just a couple mA, up to 5A or so) using the usual TRIAC + opto-isolator combo (in my case, ...
63 views

### Powering buck converter using charged capacitor

Is it possible to design a buck converter using a charged capacitor to get regulated voltage output? When the capacitor voltage falls below some threshold value the inductor should be able to provide ...
50 views

### Switching between power sources with microcontroller

I need a way to switch a load(a high power LED) between two different power sources(50v and 100v) using a logic signal, quickly(<500us) and repeatably. I was going to use an n-channel high side ...
104 views

### Methods for increasing output power and efficiency of a ZVS flyback driver

I have built the following ZVS driver: I am using this circuit at a resonance frequency of 150kHz. My hope is to be able to modify this circuit for wireless power transmission. With that being said, ...
118 views

### Flyback converter can't power load

I'm working on a Nixie tube clock and I'm having issues with the power supply. It's a flyback converter based on the LT3757 and the Coilcraft DA2032-AL flyback transformer. I designed to work with an ...
34 views

### Attenuators in Waveguides

Let's consider for instance a rectangular waveguide with TE01 mode. As shown here, a possible attenuator may be realized with a metal card placed so that it is tangential to the electric field. Here ...
211 views

### How to connect Electret Microphone module and OPAMP?

I am trying to build a circuit that gets electret microphone input and maps into 0-1V for utilizing in ADC. The microphone module suggests using such circuitry When I tried that circuit and talked ...
65 views

### Can a Capacitance Multiplier be used with high voltage outputs?

I am designing an SMPS which two output voltages of 5kV and 2.5kV. My transformer is split into four equal sections, each feeding a FB multiplier, connected in series to form the final voltages. ...
78 views

### Bipolar transistors that only connect via base to emitter

I am trying to understand how to use this configuration of the LTC2992 power measure IC and the only part I am confused with so far is the two transistors which I have circled. What I know so far ...
327 views

### 2 Switch Forward Converter Volt-Sec/Charge Balance

I am attempting to design a 2 switch forward converter. I understand how to do the volt-sec balance and charge balance when the converter is as shown in the ideal 2 switch forward converter below. I ...
97 views

### High frequency switching applications

I was reading that for high frequency switching applications with semiconductors, the ratio of the electron to hole mobility should be high. Why is it so? Is it a necessary condition always? Or ...
64 views

### How does a MOSFET conduct in saturation region?

It is a simple question but I could not find a straightforward answer. When a MOSFET enters saturation region, the channel length starts to decrease, and the channel width is the smallest near the ...
339 views

### What is happening to this vacuum tube?

Iām trying to repair a 63 year old record player. Opening it up, all of the electronics have aged badly, except for the drive motor, which is basic enough that it operates properly. I know enough ...
457 views

### Average current mode control compensation

This is the structure of average current mode control (source here). Please look at signal $V_{com}$ at the positive input of PWM modulator. For proper operation, in steady state the magnitude of ...
357 views

### Ceramic capacitor in High voltage DC link

In motor drive application the high voltage dc link between the rectifier and the inverter usually have: a bank of aluminium electrolytic capacitor a film capacitor near the inverter Is there a ...
472 views

### How to connect four different ground planes in the same PCB?

I am working on a project which uses the LTC4020 multi-chemistry battery charger from Linear Technology. The design includes a microcontroller ( NXP KL25Z) to provide additional outputs and ...
1k views

### Designing a DC 12V 80A Power Distribution PCB panel and heat sinking

Background I'm trying to build a small hobby grade ROV for an underwater robotics competition held at the university I'm studying. And I have used eight brushed dc motors each of which consumes 8A on ...
24 views

### Automotive 20:1 Oscilloscope Passive Attenuator Design

I'm currently working on designing a switched, passive 20:1 attenuator for use in an automotive educational environment on PicoScope PC based oscilloscopes. In automotive electrical diagnostics, it's ...
52 views

### Power Supply AC/DC Power OK Signal Control

I will combine 4 ac/dc converter (1000 W) by using parallel operation mode to create 4 kW unit. I will add 4 LEDs to observe converter signal health. There are digital output including POWER ON ...
31 views

### Appropriate resistor values for 5V LNK low-power supply in CC mode

UPDATE: QUESTION SOLVED/CLARIFIED. PLEASE REFER TO THE LAST "HAND MADE" SCHEMATIC IN THE SERIES OF PICTURES BELOW, AND READ MY FINAL "SOLUTION". Original question: * I wonder what ...
41 views

### Calculate dead time in synchronous buck converter

How much dead time is required for the switches in synchronous buck converter at a switching frequency let's say 1 kHz. Is there any thumb rule for choosing dead time with respect to the switching ...
34 views

### Simulation of distortion from output inductor in class D amplifier, e.g. inductor non-linearities modelling

I'm new around here :) So, I am doing a university project regarding the effects of the output filter of a self-oscillating class D amplifier for low frequency audio signals, e.g. subwoofers. The ...
46 views

### Oscillating a circuit on and off repeatedly to save water

I am using a foamer unit (a device that intermittently drops a blob of foam behind a moving vehicle to mark its path). The problem is that it's dropping about 10 x more foam than I really need, hence ...
32 views

### How to calculate the maximum voltage of square signal from Erms?

How do you calculate the maximum oltage from Erms when you have dc and ac component?
15 views

### Calculation of Rated Power for IGBT Module

For an IGBT module with the following characteristics, how can we calculate the rated power? I mean how much is the rated power for this module?
50 views

### What's wrong with the wiring of my multiplexer?

My circuit is wired as shown above -but with the EN pin I've tried connecting to ground and to power. I don't think its a code problem because when I wire inputs in directly everything reads normal. I'...
15 views

### Power/Battery Management System Prototype: Custom PCB or Evaluation Modules from TI?

I am developing a battery/power management system for a medical device that runs off of 12VDC. I notice that TI offers a lot of evaluation modules in power management, and wonder if I should start ...
39 views

### Can someone help me understanding the working of 3-stage comparator/ discriminator, shown in attachment?

I am working on a project and I need a high DC gain comparator for it. M1,M2 are tge main differential amplifier and M1a, M2a are used for hysteresis. As per my understanding its a 3 stage comparator: ...
74 views

### SMPS Grounding and Earthing

I'm trying to design the isolated SMPS circuit. I'm a newbie on power electronics and I'm using a circuit design tool to design SMPS. I have confusion about grounding and earthing. My system will have ...
57 views

### TL494 current limiting without current sense

Is it possible to limit the current without using current sense feedback in TL494?? The TL494 have two amplifier both of them sensed only voltage (12V_A & REF) from buck regulator and TL494 limit ...
67 views

### Will adding a DC-DC converter affect how a modern car operates?

I'm thinking of adding a wireless charger to my car, and adding a Buck Converter to step down the 12V source to 5V for efficiency sake. However, I am worried about the emissions from the DC-DC ...
76 views

### Maximum Power Point Tracker (MPPT) charge controller - what drives the weight?

I'm having trouble finding any literature paper that studies this problem. What drives the weight of an MPPT charge controller? How would I go about reducing that weight if I had to design a custom ...
77 views

### Can I increase my power output from my solar panel using a capacitor?

If I have a 3V, 70mA solar panel rated at max 210mW. If I design a RC series circuit with it, can I increase the power outlook to about 2W? If so, how can I determine the time it takes to charge? Also,...
56 views

### Calculating capacitor discharge time constant with dc source and constant current source

I have a 1.8V dc source with 40 ohms series resistance, which models a battery. In parallel, there is a 10uF capacitor. At t<0, the mosfet is off and there is no load delivered to the output, so ...
95 views

### State Space Average Model of Non-Ideal Buck Converter

I've been learning power electronics and am trying to design a dual-switch forward converter. One of the things I've been trying to do is derive the small-signal equivalent circuit of the non-ideal ...
47 views

### What is the value of this shunt resistor from a drone power distribution board?

What is the value of the shunt resistor shown below? It is from the drone power distribution board, rated for up to 120 A. I am guessing, that the value is 0.25 mOhm. However, even with this value, at ...
55 views

### Inverter EMI filter design

I'm designing an inverter with a switching frequency range of 10-40kHz. The inverter will run off of a DC power supply at a relatively low voltage (30-80VDC) and low power (~100W) for motor control ...