Questions tagged [flyback]

A flyback diode is a diode used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply voltage is suddenly reduced or removed. A flyback transformer, also called a line output transformer, is a special type of electrical transformer designed to generate high voltage sawtooth signals at a relatively high frequency.

Filter by
Sorted by
Tagged with
0
votes
1answer
28 views

Designing a compensator - Control system - Missing value

I would like to determine the transfer function of the following circuit made of TL431. According to the different AN that I have read (and about this subject I really really thank Christophe BASSO, ...
1
vote
1answer
36 views

Determining error in output voltages of a flyback converter

I'm currently designing a flyback converter and I just want to know how the error tolerances are calculated for a multi output flyback converter. I calculated the required primary number of turns: ...
1
vote
2answers
88 views

How can I make my flyback converter discharge immediately?

I'm using a flyback converter (220-100V to 19vdc) to power an electronics unit. But it doesn't discharge fast enough, this causes some relays to stay energised for a second or two after power supply ...
1
vote
0answers
20 views

Flyback converter Transformer calculation verification

Kindly verify the transformer design for this wide input power supply using LM5022 i am designing the power supply for my solar inverter in which output of solar panel (750Vdc to 800Vdc) directly fed ...
3
votes
1answer
54 views

Getting an unencrypted PSPice PSU Control IC working in LTSpice

I am currently working on a flyback converter design based on the TI UCC28C42 multi-topology controller IC, and would like to simulate my circuit in LTSpice. I have created a small-signal averaged ...
6
votes
1answer
475 views

PCB Design position of flyback diode for motor

I have a simple question: If I design a PCB, does it physically matter at what position my flyback diode for my motor is? Does it matter if it's "in front" of my MOSFET or not? I made two ...
2
votes
2answers
74 views

Why is there a huge difference between Is2(peak) and Is2(rms) in flyback converter?

I try to design a flyback converter which has two outputs. First output is main output 24V/1A and second output is for Vcc 18V/0,02A. Total output power -> Po = 24,4W Efficiency = 85% So, input ...
0
votes
2answers
102 views

What is this transformer, is it package only without coil or complete transformer?

I did a simulation on TI Power Bench for a isolated power supply, There I got transformer spec in BOM, Core=Wurth Elektronik , CoilFormer=Wurth Elektronik Core=150-2340 , CoilFormer=070-4477 Core Type ...
0
votes
2answers
59 views

Is there a way to know if there is a flyback diode?

I have two 12V water pumps that I want to control with an Arduino via a relay. They are generics and I am unable to find a reliable datasheet: Good Pumps with Rohs Motor: Goso GB37-530 Is there ...
1
vote
1answer
74 views

Back EMF in sensored BLDC motor

In hall sensor based BLDC motor, motor is controlled by feedback of hall sensor. At a time only 2 stator pole pairs will be excited and 3rd pair will be ideal. So in third pair Back EMF will be ...
0
votes
2answers
67 views

Isolated Flyback vs Isolated Buck Voltage converter. What are the Pros and Cons?

I am working on a project where I need an isolated power supply. My input is 10-20V and I am looking to get an isolated 3.6V out @ 5A or more. My priorities are easy of implementation, voltage ...
1
vote
1answer
56 views

TVS flyback diode placement

I'm switching a solenoid with a relay. The relay has failed after just a few hundred operations, I suspect because of the flyback from the solenoid. I have a P6KE20A TVS diode that I want to use to ...
0
votes
0answers
40 views

ESD Protection for flyback diode - Relay circuit

I am designing a board to accommodate relay and flyback diode with IO connector in a PCB. The low side driver of relay will be present in another PCB. Both the boards will be connected through wires(...
0
votes
1answer
67 views

Why did the designer of this flyback circuit choose to set the oscillation frequency as high as possible with the smallest resistor tolerated?

This circuit uses a current mode controller with an oscillation frequency response of: In the circuit, the designer chose to use a 10nF cap, with a 680 ohm timing resistor, which according to the ...
0
votes
1answer
57 views

Do I need to suppress ringing in a flyback converter?

I am about to design a flyback converter. As all flybacks with no extra measures it has some ringing. You can see that ringing in this example from -1µs to 4µs: This ringing can be surpressed by a ...
0
votes
1answer
57 views

LTspice - Flyback simulation misunderstanding

I am trying to understand how to compute the rms current through the output diode of a flyback with multiple outputs. To make it simpler, I did not add the leakage inductance of each windings. Here is ...
0
votes
1answer
66 views

RMS Current through output diode in a flyback transformer with multiple outputs

I clearly do not understand where does this formula comes from ... (I did not find it on internet) $$ \mathrm{ I_{diode_{rms}} = \frac{\sqrt{1+\frac{A²}{3}}}{\sqrt{1-D}}*I_{out_{avg}} } $$ where Iout ...
1
vote
0answers
60 views

Modify Spark Ignitor Circuit for Bug Zapper Functionality?

I have been doing some research on building my own bug zapper circuits for use in an art project (just for arcing electricity, I'm not killing any bugs), in particular finding a good source for ...
0
votes
2answers
61 views

What was the point of an “alignment scope” like Kikusui 5091, and can anything be done about it's dismal horizontal bandwidth?

I got this Kikusui 5091 used for US$ 50 bucks, as a reward for my pretty successful attempt to create a digital raster display from scratch on my oscilloscope, and finishing off my Game of Life in ...
2
votes
1answer
133 views

Flyback output ripple voltage formula

Does anyone is able to demonstrate this formula? Where Co is the output capacitance, Rc is the ESR associated to the capacitors, Io is the output current of the particular output, fs is the switching ...
0
votes
0answers
36 views

Ripple voltage on output voltage of an smps

I am trying to select the output capacitors of a flyback topology (without using a second LC filter). This is a general question. My question is how evolved the ripple voltage in function of the ...
1
vote
1answer
47 views

What is the difference between magnetic and primary inductance?

I try to calculate ramp compensation resistor (Rcomp) for flyback SMPS converter design. For this, I examined slope compensation section at page 15 in NCP1252 datasheet by OnSemi. But, there is a ...
1
vote
1answer
41 views

How to find the secondary inductance value in flyback transformer?

I try to design smps converter with flyback topology. Parameters are below: Vin = 100V(dc) (constant) Vout = 50V(dc) D(on) = 50% (So, D(off) = 50%) fsw = 70 kHz Np/Ns = 2 According to my calculations ...
0
votes
0answers
21 views

characterize internal capacitor of optocoupler

I am reading article Using an automated Excel® spreadsheet to compensate a flyback converter operated in current-mode by Christophe Basso, Tomas Petrek/David Sabatié. In page 12, they explained how we ...
4
votes
2answers
105 views

Why can't I get any proper arcs out of this flyback transformer?

I salvaged a flyback transformer from an old TV and used it in a single MOSFET driver like this: I used 6 turns of insulated copper wire to make the primary coil with the centre tap and again 6 ...
1
vote
1answer
101 views

What happaned when the flyback transformer is in saturation?

I am trying to design a DC-DC flyback converter. Input voltage is 110V and output voltage is 24V. I have used NCP1252A PWM controller. Flyback transformer windings: Primary -> 24 turns Secondary -...
0
votes
1answer
39 views

Ltspice - Simulation problem of cross regulation in a multiple output flyback

I am trying to show the effect of the leakage inductance on a multiple output flyback. According to those documents from Unitrode and texas instrument (this one : https://www.ti.com/lit/ml/slup081/...
0
votes
0answers
71 views

How To Source Transformer Component for Bug Zapper Circuit

I am looking at designing a small bug zapper circuit of the type described in this post: How does this mosquito zapper circuit work? Here is an approximate schematic of what I am trying to build: I ...
0
votes
3answers
97 views

Energy Transformation in Flyback Transformers

I am trying to understand how is energy transferred as a current to secondary of flyback transformer. First due to the dot convention and secondary side diode, current will not flow in secondary and ...
0
votes
1answer
41 views

Does a solid-state DIN relay typically need a flyback diode when switching an inductive load?

I'm using this Phoenix Contact DIN rail relay, DigiKey part 277-17665-ND (data sheet). I thought it would be prudent to add a flyback diode, but looking at the data sheet, it vaguely suggests it ...
0
votes
0answers
39 views

PSR Flyback Power supply

From this Reference Design I have two questions: They are doing PSR (Primary Side Regulation) with LM5020. However, according to the datasheet LM5020 is a Current Mode PWM Controller which was not ...
2
votes
1answer
226 views

How to protect GPIO from back current? Diode? [closed]

After frying a Rpi with this montage 6 months ago: I followed advice from kind users here and modified the wiring to this back in February: It has been working fine for 6 months and suddenly ...
0
votes
0answers
24 views

CFL Ballast Calculate Primary Turns

There are online designs that use a simple ferrite bolt 50 turn primary and 500 turn seccondary powering one 5 watt CFL. I attempt to customize it with: Specs: TDK Core (source) Vin primary= 6V DC ...
1
vote
2answers
294 views

Problem connecting transistor, flybackdiode and relay

I am a new person with tinkering electronics as I am from Computer Engineering. I am working on a project with arduino that consists of a relay, I researched from the internet and found out that a ...
1
vote
1answer
109 views

Simple self oscillating flyback converter [duplicate]

Please am studying about switching power supplies, starting from the simple ones. I've just concluded on joule thief and blocking oscillator, now am progressing to Self oscillating flyback converter(...
4
votes
1answer
62 views

High Voltage Half Bridge Drive

I am working on a project to produce high voltage output. Since I supply this circuit directly from mains I have some problems. Here is my representative circuit: I am controlling transistors from a ...
1
vote
2answers
130 views

Multiple output Flyback - Stacked transformer - Cross regulation - TL431

Suppose I have the following output stage of a flyback: simulate this circuit – Schematic created using CircuitLab The schematic is a bit simplified but the idea is here. Do not pay attetion to ...
0
votes
0answers
34 views

Gate drive circuit for 1500VDC two switch flyback converter

I am designing two switch flyback converter for 1500VDC input solar application. I am little bit confused while selecting gate driver circuit, specially for high side gate drive. I didn't find any ...
0
votes
0answers
76 views

Snap-On impact driver Flyback Diode identification

I have a Snap-On impact driver with a blown diode. I believe it's a flyback diode as it's on the output of the switch up to the motor. I can make out several markings on the diode. C39 and C5, there ...
0
votes
1answer
69 views

Can flyback transformer used for push pull converter? [closed]

I am electrical engineering student and I am working on capstone project now. We decided to make paralleing input and series output push pull converters. (So combining two converters) However, we ...
1
vote
0answers
82 views

Altium Simulation Reference Ground

I have a question about Flyback converter simulation on Altium. I set my reference ground GND. When I try this schematic with all grounds as GND like below Simulation is working good as you can see ...
1
vote
2answers
83 views

Voltage Mode Control

Since i started my training about design of DCDC I'm really confuse with control part. At school i learned that DutyDycle=Vout/Vin for Buck, and that's it. But now, i see that, Duty cycle is set ...
2
votes
1answer
65 views

Altium->Coupled Inductors

Im glad to be with you. I have question about coupled inductors in altium. I want to make a flyback converter and tried first as in Image 1 . I converted 310V DC to 12V DC as you can see. I wrote ...
2
votes
1answer
114 views

Understanding this startup circuit

In the circuit below, how is Q1 turned on? When there's voltage in the bias winding, it turns Q2 On and subsequently turns Q1 off. Also, does the end of R4+R7 keep floating when Q1 is off? It should ...
0
votes
1answer
54 views

High voltage Flyback transformer polarity

This circuit is a high voltage generator using flyback transformer. It works well, but i thought it shouldn't working by this polarity of the feedback winding ! I mean when the voltage on the ...
3
votes
2answers
470 views

Design R C snubber for flyback converter

I have a DC/DC flyback converter and I need to design a snubber. I already know the diode to use I just need to design the R and C value. Now, I have simulated my circuit and tweaking values on C and ...
0
votes
0answers
28 views

Solenoid flyback considerations in this pFET/nFET inversion circuit

I am trying to combine FETs, where logic permits, to reduce the size of a pcb. Is it poor practice to have the pFET's gate and nFET's drain shared by an inductive load that will usually be grounded ...
0
votes
1answer
55 views

Designing Startup Network for Flyback Controller

I'm trying to design a startup network for this flyback controller, see the picture at the end. I want the controller to start within 10 ms at most. This is what I'm doing: Due to the wide input ...
0
votes
1answer
33 views

Calculate duty cycle of flyback converter

I have the following problem: MY ATTEMPT I found a formula for the DC transfer function for the flyback converter: $$\frac{V_{out}}{V_{in}}=\frac{N_2}{N_1}\cdot \frac{D}{1-D} $$where \$ \frac{N_2}{...
1
vote
0answers
39 views

How to Determine Input Capacitor Value for Peak Power Requirement

For flyback SMPS, how do we know that our input capacitor value is sufficient for some peak power requirement? I understand that bigger input capacitor will have more advantage on this peak power. ...

1
2 3 4 5
9