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
0answers
26 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
50 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
34 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
31 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
174 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
268 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
56 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
59 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
107 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
28 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
58 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
64 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
80 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
79 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
46 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
110 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
35 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
250 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
24 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
49 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
29 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
37 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. ...
0
votes
1answer
45 views

Transformers and switching converters [closed]

I have been reading about the concept of flyback transformers and converters, which has led to various misunderstandings concerning the basic operation of a transformer. Firstly, dc current don't ...
0
votes
0answers
41 views

Capacitors in series for higher voltage applications

From the second circuit below, the red area is a startup network. The App Note states: My question is, if I have three capacitors in series because my application reaches 1100V, then the bus voltage ...
4
votes
1answer
93 views

Transformer overheating reasons

I am currently designing a Flyback-based offline AC/DC converter similar to the following schematic (with a few changes e.g. sync rectifier at the output). Everything works nicely but the custom-made ...
0
votes
1answer
38 views

Input capacitor in buck converter

I've chosen this Reference Design as starting point. Here the schematic. I'm using full wave rectifier instead. I'm designing a buck converter with these requirements: Input voltage: 120-690Vrms AC ...
1
vote
1answer
35 views

ISO 7637 Supply Transient pulses - Explanation

I am trying to design an input power supply filter circuit inorder to protect from ISO 7637 pulses. I am referring this Little fuse app note There seem to be different pulses. Pulse 1, 2a, 2b and so ...
1
vote
1answer
47 views

Current Theshold Pin of Flyback Converter controller

I am designing a PoE PD with integrated flyback converter controller based on LT4295. I understand most of it but the ITHB Pin (current threshold pin for primary MOSFET) gives me headache. I do not ...
0
votes
1answer
92 views

Schottky diode as a flyback diode with PWM?

I found similar posts but need little more hand-holding - no engineering background. I tried to document the circuit to my best ability but i recognize its far from perfect: I was reading these two ...
0
votes
1answer
67 views

How to properly assemble a flyback transformer?

I have generated a transformer assembly project online for my flyback transformer. The Diagram: The Winding instructions: How do I connect the Primary First coil ...
0
votes
1answer
26 views

Understanding this clamp network

The circuit below is from this Reference Design. I want to understand the clamp network at the input. How is VGS of Q1 kept at a safe level?
1
vote
2answers
82 views

DC Motor pwm control and flyback diode question

Suppose we are controlling a dc motor via pwm. he motor has a flyback diode across it. Question : During pwm off period, the motor current freewheels through diode. Won't the motor experience a ...
1
vote
3answers
49 views

Using a DB3 diode as a flyback for a 24vdc relay

Can I use the DB3 diode as a flyback for a relay that works on 24v dc? [![enter image description here][3]][3] This is a new photo : [3]: https://i.stack.imgur.com/Snv9f.jpg
3
votes
1answer
87 views

Flyback AC/DC based on UC28881 - TI's reference design - not working

I have build the AC/DC flyback converter according to TI's reference design but ist is not working and I am wondering why. By the way: I have build the 5 V version, so everything connected to T1:9,7 ...
0
votes
1answer
38 views

Output Voltage of a Current Mode Controlled Flyback Converter

I'm trying to use the NCP1014 (65kHz) to make a flyback converter. I'm using coilcraft's transformer B0570-BL which is specifically designed for the NCP1014, with turns ratio 1:0.06 or 16.67:1. I ...
0
votes
2answers
72 views

Flyback and electron flow

sorry in advance as english is not my mother tongue. I have been using electron flow point of view for ages for analyzing and designing circuits (disclaimer: I have a background in computing - not ...
0
votes
2answers
62 views

High voltage input/Low voltage, low current power supply

Most of the times, metering devices are low power devices powered from high voltages inputs. Let's say I have 600V three phase, what would be a good approach to get 5V/50mA or 12V/100mA from this ...
0
votes
3answers
26 views

When to not use electrolytic caps at the input of flyback converter?

This reference design does not use bulk capacitors at the rectifier output. It uses small ceramic capacitors. On the bright side, I like it because it eliminates the reliability issues of electrolytic ...
0
votes
1answer
54 views

Misunderstanding about flyback transformer and turn ratio

Here is the flyback that I m studying. It is a flyback transformer. I am confused about the different turns ratio. If I suppose the input voltage minimum and so the duty cycle maximum (i.e D = 0.5), ...
1
vote
1answer
61 views

Driving a small water pump with a microcontroller and a transistor

I have bought some water pumps for a project I am currently working on, the thing is that I have never used water pumps before, I am sure that pumps are inductive loads, but I am unable to know the ...
2
votes
0answers
53 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, ...
0
votes
3answers
45 views

What is LT3748 Sense Resistor Power Dissipation?

I am using LT3748 for Flyback converter design. In datasheet (https://www.analog.com/media/en/technical-documentation/data-sheets/3748fb.pdf), given formula for Rsns value (pg 21) is Rsns=100mV/Ilim, ...
0
votes
1answer
54 views

Reduce Flyback Reflected Voltage Ringing?

I have a step-up flyback design with the following parameters: \$V_{in}=24V\$ \$V_{o}=150-350V\$ \$P=15W\$ \$N_{ps-ratio}=1:7\$ The transformer is not ideal with 1:7 and the inductance is a bit off, ...
1
vote
1answer
93 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 ...
1
vote
1answer
58 views

Flyback converter Transformer design- N87-etd29

I have designed a Flyback using UC3845, PCB and components assembling are done. But I have some problem in transformer. My primary winding is 40 turns ( 2 paralell 0.40mm), and secondary winding is 9 ...
0
votes
1answer
47 views

How much current can I draw from one of the output of a transformer

I have a flyback transformer which I took off the shelf. It has 6 outputs: 4 at secondary side and 2 (+1 input) at primary side. I'm able to approximately know consumption of each output. How much ...
2
votes
1answer
94 views

Flyback transformer vs neon sign transformer

I've been working on my spark gap Tesla coil, and I'm planing to use a 5kV 30mA neon sign transformer connected to a voltage multiplier circuit with 10 stages to get a higher voltage. Could I use the ...
2
votes
1answer
95 views

TL431 Loop Compensation

I'm trying to understand this material from C.Basso regarding TL431 compensation (Designing Compensators for the Control of Switching Power Supplies If you refer to pg.110, there is one example ...
0
votes
0answers
15 views

Peak Recovery Current in Inverter Diode

I have an H-Bridge module comprising four IGBTs with flyback/inverter diodes incorporated [Vincotech FZ074PA075SM] which is intended to reverse a current of around 50A in the circuit to field coils of ...

1
2 3 4 5
9