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.

5
votes
4answers
2k views

Does the IR2110 need a gate resistor?

The datasheet of the IR2110 shows this as the typical connection: And in some cases even a gate-source resistor is used, as in this and this post But the app note shows this as the connection for a ...
5
votes
3answers
2k views

Generating electricity by moving a door

I'm entirely new to electrical engineering. This is for a hardware/software project I have in mind, where I need electricity without having to plug the device into a power source. My intention is to ...
5
votes
1answer
30k views

Q-Point of a circuit

In a BJT or MOSFET circuit we have this curve: What is that q-point? From my research I have the following information: The operating point of a device, also known as bias point or quiescent point ...
5
votes
2answers
173 views

Why are there no power JFETs?

After doing a search on mouser, I found only 4 JFETs rated for more than 1A drain-source current, compared to almost 3,000 BJT and 11,000 MOSFETs. Is this because there is less of a market for a high ...
5
votes
1answer
331 views

“Correct” way to attach cable to this specific kind of banana plug

I bought a set of banana plugs of the style shown here (with rough 3d model to clarify the shape of the terminal because shiny metal is hard to photograph!). The site I got them from (here) didn't go ...
5
votes
2answers
2k views

Induction heater circuit problem

I am trying to build induction heater with the help of the following schematics(taken from this page): So I am using 220:10Vrms(15Vpeak) transformer with fullbridge rectifier and a capacitor to get ...
5
votes
1answer
316 views

Thyristor/SCR \$i^2t\$ and \$i^2\sqrt{t}\$ Rating

I have commonly seen the \$i^2t\$ rating for fusing in a SCR datasheet. This is a helpful rating for assessing if pulses which exceed the surge current rating (Itsm) of the SCR will damage it. ...
4
votes
3answers
523 views

1117 Regulator input voltage

First, a little background - I'm working on replacing an old (late 1970's) output driver board. The old equipment this came off of has a very dirty and poorly-regulated 5V system. Since I'm using ...
4
votes
5answers
5k views

Is it a good idea to connect the Neutral point to your common ground in your PCB?

I am making a PCB that uses AC Mains power where 120VAC is converted to 5VDC with the help of AC/DC converter. The 5V output is then supplied to my digital circuitry. The main confusion I have is to ...
4
votes
5answers
17k views

What to plug in first to usb charger when charging: wall outlet or cell phone and why? [closed]

I asked this question on Physics StackExchange but was advised to ask it here. When I charge me cell phone or notebook or whatever device what should I plug in first? Should I at first plug in usb ...
4
votes
2answers
564 views

Capacitor and inductor working principle

I want to know that there is opposition mechanism of current in inductor say back emf than what is opposition mechanism of voltage in capacitor ??? And also want to know that when inductor suddenly ...
4
votes
3answers
514 views

Current Measurement. 50Amps 0.5% error margin

I am working on a solar energy project and I'm using a 10 panel array. For monitoring purposes I'm using a combiner device which tracks various data parameters like current, voltage and temperature. ...
4
votes
1answer
361 views

Feedback in LM2574

I wonder what is the purpose of 'R66' at the feedback terminal of LM2574? I have seen its datasheet but I cannot find info about this. Instead of a single resistor there is a voltage divider shown in ...
4
votes
5answers
3k views

How to control power to a water heater

My water heater element is rated at 3.6kW at 240V. To use solar power efficiently, I would like to use excess solar power (in a grid-tied arrangement) to heat our domestic hot water. Our electricity ...
4
votes
5answers
271 views

Dissipating Heat from Tiny Components

I need a 5v 2.5A output in a handheld device and have settled on the TPS61235P. Its 2.5mm QFN package was very hard to solder, but I finally got a board fabbed and tested it out. After roughly a few ...
4
votes
1answer
8k views

Switching frequency of a solid state relay?

I bought a SainSmart 4 channel solid state relay recently. I am planning to use an Arduino to control some Christmas lights I've put up around my home. My question is: How fast can you switch SSR's on ...
4
votes
2answers
496 views

Speeding up turn-on and off with VOM1271 Photovoltaic MOSFET Driver (/optocoupler)

It's my first post here so please do not hesitate to tell me if I'm not doing it right :-) A bit of context : we need to switch an array of power resistors (1,3kW, 1ohms) in order to test under load ...
4
votes
6answers
1k views

Does output voltage of a boost converter depend on load current in CCM?

In the thread below, there are different opinions whether output voltage of a boost converter operating in continuous conduction mode (CCM) depends on load current or not. Boost Converter Output ...
4
votes
1answer
260 views

What is the current component at the input of dc-dc converters?

The table below describles state space analysis in the field of power electronics. It is from a paper entitled "Signal Flow Graph in Loop Gain Analysis of DC–DC PWM CCM Switching Converters by Wing-...
4
votes
3answers
720 views

TVS for 48v system

I have a 48v battery powered system is charged by normal lead acid charger that might reach up to 14.5v and maybe 15v per battery ( total 58v to 60v ). The circuit contains components rated for 75v ...
4
votes
1answer
308 views

High Voltage Power Supply Design

I need to charge a 1000uF 400V capacitor bank off of a 7V LiPo battery within roughly 5 seconds, and have the circuit be as small and light weight as possible. With a constant voltage supply and a ...
4
votes
3answers
4k views

Voltage divider Biasing of transistor

In this amplifier circuit we are using a voltage divider bias. Why can we consider that voltage produced by R2 is actually providing voltage to the base. What is R1 doing?
4
votes
2answers
499 views

High-side vs low-side reverse polarity protection

I need to make a reverse polarity and over-voltage protection for a fairly powerful device (45W @ 12V input) and after some research I noticed a weird peculiarity. A typical reverse polarity ...
4
votes
2answers
658 views

Is it safe to use narrow but short PCB traces for high current flow?

I am trying to design a PCB which has high current traces on it. PCB has 1 oz (35 um) trace thickness. Maximum current flow is going to be 12 Amps RMS. I found this online PCB thickness calculator: ...
4
votes
2answers
8k views

Using the TP4056 to charge a LiPo battery and supply power to my circuit

My goal is to power a 5V circuit using a rechargeable battery with an optional USB power source. I have a TP4056 battery charger (with battery protection circuit) to charge my 3.7V 900mAh LiPo battery ...
4
votes
2answers
257 views

Supercapacitor with a rated voltage value greater than 2.7V feasible?

I've been researching into the development of electrical power units for Automotives (motorsports in particular, as I participate in my Uni's Formula Student team) and have started by looking into the ...
4
votes
2answers
393 views

Flyback Converter Capacitor Value selection with given ripple voltage limit

I need to design a flyback converter for my project. In my design the output voltage is 15 V. I calculated all the parameters including inductance values, diodes selection etc. However there is a ...
4
votes
1answer
963 views

Induction cooker - highly irregular power transfer curve

I’ve designed a Class D series resonant inverter, for use in an induction cooking application, which is displaying a strange behavior in its measured current vs frequency curve. The topology, ...
4
votes
2answers
4k views

Why do we use a diac for triggering a triac?

I mean, Wouldn't it be possible to give a gate pulse on triac directly? I have seen in many phase control application circuits like fan speed control,the usage of diacs to trigger a triac.
4
votes
4answers
11k views

Current sensor measuring circuit

I am planning to design Rshunt basis current measuring. My current measuring range is 1A~2A. I need analog output of 0~5V analog with 1% accuracy. How can I do this? I found conversion circuit here. ...
4
votes
1answer
114 views

Want Square Waves based on Injection Timing of 4-Stroke Engine

Recently, I am working on ECU of CNG Auto Rickshaw having 4 Stroke Engine. Here, Image shows the Engine of Auto Rickshaw. I have already taken reading of MAP, TPS and RPM. And now I am working on ...
4
votes
1answer
272 views

Safety Capacitor Selection

When selecting an X2 safety capacitor what must be taken into consideration. There are only a few types of capacitance ranges and seem to be chosen based on voltage rather than capacitance. Take ...
4
votes
3answers
687 views

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 ...
4
votes
2answers
434 views

High Step-up Ratio DC-DC Convert (12V-to-150V) - Boost, Flyback, Coupled-inductor Boost?

I am trying to design an on board DC DC converter that generates 150V from a 12V input. I'd like to design it to handle at least a 30-50mA load, but in reality the load will most likely be smaller. ...
3
votes
2answers
2k views

Unknown electrical component in circuit

I was checking out a circuit for power management. That's when I came across this unknown component which looks so much like half a transformer and a switch. What exactly is this?
3
votes
3answers
1k views

Why do we want higher power factor in ac motors?

Here is a simplified 3P electric motor below: This motor is simply combined of three coils facing toward to the rotator (in the center) 120 degree apart to each other. The user wants his rotator to ...
3
votes
4answers
240 views

Burning a Power MOSFET

We are doing battery heat testing and want to be able to vary the current in the circuit to different test points up to 100A. Our circuit schematic is attached. The MOSFET is IXFN360N10T. We attached ...
3
votes
3answers
3k views

In a car, what is the difference between a 12-V and a 24-V system?

As I understood, 12-V car system refers to automotive system that runs with a 12-V battery. What are the basic differences between a 12-V and a 24-V (actuators, ECU...) ?
3
votes
1answer
444 views

Symmetric vs Asymmetric PWM

I am working on Control of Power Converters, I was reading TI's piccolo DSP ePWM guide and came across symmetric vs asymmetric PWM, I have a good basic understanding about converters, DSP and all. ...
3
votes
2answers
923 views

Spark when connecting battery module to DC power supply

I am using a 60v DC power supply to charge a 48v battery module. I set current and voltage limits first, turn off the DC power supply, connect positive to battery's positive side. When I try to ...
3
votes
2answers
441 views

Learning transistor based circuits

simulate this circuit – Schematic created using CircuitLab In one of our electronic circuit tests, this question was asked: What is the output voltage of given circuit? This circuit looks ...
3
votes
1answer
567 views

Why is Junction Temperature called so?

Why is the silicon die temperature inside a semiconductor device referred to as "Junction" Temperature ? Though this name may make sense for minority carrier devices where there is maximum power ...
3
votes
4answers
384 views

Is the Nyquist plot useful in actual electrical engineering?

I am currently doing a course on linear control theory, and we are covering Nyquist Plot to study phase and gain margin. I find myself unable to appreciate this concept. One, the proof of the Nyquist ...
3
votes
3answers
766 views

Push current source through transfromer

This lecture (from page 130) shows manipulation of the buck-boost converter model into canonical form. I am stucked at moving current source through transformer as in the picture below or from the ...
3
votes
1answer
1k views

How does this FM transmitter work?

I'm an electronics student and I have been trying to understand this FM transmitter diagram (taken from electronicshub.org) for a long time. I had put efforts to learn it by surfing the web but parts ...
3
votes
2answers
388 views

DC current transmission loss vs. conversion loss

I'm going to transmit about 7 Watt DC over 4 meters long twisted pair Ethernet cable. I'm thinking of using Buck and Boost converters to step-up to 30 V and step-down to 5 V the voltage before and ...
3
votes
1answer
3k views

BLDC PWM frequency

I am driving a BLDC motor using a 6-step commutation table at a 40kHz PWM frequency and I am at a loss choosing the optimal one. I understand that the max frequency depends on the motor's R/L ratio ...
3
votes
5answers
4k views

Run heater on two powerlines, where the second line is switched according to the main line

I got a water heater which is rated 6kW. The "heating element" consists of 3 heating elements that are connected in series for 1-phase usage. I would like to run two of those heating elements on one ...
3
votes
5answers
399 views

Ripple current in synchronous buck converter

I am designing a synchronous buck converter and I am at the bread board stage in my design. I wanted to check the current waveform through the inductor, but I do not have a current probe available. I ...
3
votes
3answers
388 views

Reversible Constant Current Source (CCS)

I need a current source, that can work in both directions. To make it simple, I need to generate a square signal in current. I am currently using a simple H-bridge, but without any current regulation. ...