Questions tagged [ac-dc]

Questions regarding the safe and effecient design and implementation of AC voltage to DC voltage supplies. Typically Mains to some lower DC voltage.

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65 views

Positive and negative rail for op amp circuit

I need a positive and negative rail to power an op amp Since it's an op amp for a voltage reference, would using a circuit like this one be enough? Input voltage is unregulated 37 volts, with 4.7k ...
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3answers
94 views

Discrete linear voltage regulator

I am trying to make a discrete component linear power supply. This schematic seemingly works but it doesn't work when I build it on my breadboard. I am taking 110 volts through a transformer down to ...
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1answer
78 views

AC to DC conversion: is this an appropriate implementation?

I understand that a 20v AC converter supplies 20V RMS AC. I wish to convert this to 20v DC and so have drawn up a schematic for this which includes: the AC to DC conversion, regulation, smoothing, and ...
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1answer
35 views

Output current and voltage levels regulation in ac/dc adapter

On the picture below is the output circuit of AC/DC adapter. I understand how voltage level contol works, but I don't understand how exactly current limitation works and how should I calculate ...
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2answers
36 views

Is this a reference of an AC/DC REGULATED adaptor?

I need to choose an 230 VAC / 12 VDC converter which is regulated, that-is-to-say I need the voltage to be 12 V with a current of 0 to 5 A. I found this one because it is the cheapest (price really ...
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0answers
57 views

Flyback converter with dual outputs (12V / 5V)

I came across the following flyback converter circuit, which has a dual output (12V and 5V), but I am unable to figure out why the secondary windings are connected in series. Based on the datasheet ...
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0answers
43 views

Energy Meter power supply advice/help

I've been assigned to start working on a smart energy meter project, it's been like 10 years since I put any work in AC. I would be sincerely grateful for any constructive advice. Now the 3-phase ...
34
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3answers
6k views

Computer power supplies usually have higher efficiency on 230V than on 115V. Why?

As seen here in the example, this particular power supply (and most others too) has higher efficiency when running on 230V. Given that computer power supplies are usually required to output a ...
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1answer
69 views

How to choose AC/DC adapter - high voltage low current vs low voltage high current

I got an LED light kit, 2 lights, each takes 60W, at 12-30V. I'm planning to use these lights separately, and need to choose between: 12V, 5A adapter 24V, 2.5A adapter Both will give me 60W, but ...
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0answers
17 views

AC connecting disconnecting?

I had a circuit that I wanted to turn on when I connected a plug(9 pin) 3 pins consumed by POT and 2 For a momentary switch. 4 pins remain available. Thoughts was to use 2 pin connected together to ...
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2answers
55 views

How do I safely connect a light switch button to the secondary side on a board?

I designed a special light controller board. It has a primary side that is connected to AC 230V. There are a certified AC/DC converter module and a relais, bridging the air gap between the primary and ...
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0answers
26 views

Can I use AC voltage from myRIO to power stepper motor?

I am using easydriver and arduino for a stepper motor provided on this website The motor is 17HS3401S Stepper Motor and I think this is the correct datasheet found on the internet for the same. ...
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2answers
73 views

Laying out power electronics on analog signal board, practical advice

to keep this brief I am designing some audio circuitry and also need to design the power supply. The barrel jack in the schematic below sees 18VAC and I am converting that to +/-15V DC rails. So to ...
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0answers
36 views

Power Supply Design 230 AC to 80V DC - multisim and real components

I am an young student that was tasked to build a power supply which will convert single phase 230V AC into 80V DC to test specific DC motors (custom made). I only know that under normal operation and ...
0
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1answer
35 views

Protection circuitry for AC/DC converter

I'm using the RAC02-GB (Datasheet) as an AC/DC converter and I'm confused about the protection circuit they included in the datasheet: I want to make sure the AC/DC converter has the proper external ...
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0answers
64 views

Why does rectifier output is showing DC instead of pulsating DC

I am using below circuit for PFC. Before connecting coupled inductor's auxiliary output to the IC's Vcc, I wanted to make sure that it is coming properly or not. So when I probed the red dot in the ...
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2answers
69 views

Determine the resistor required for a circuit [closed]

If I want to supply power to a device that is rated for about 2V using a DC source of 12V. How can I find the resistor o should use.
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2answers
69 views

AC/DC Converters in Series with the Same AC Source

Would it be safe to connect two identical AC/DC converters in series if they share the same AC source? My concern is that the negative DC output is grounded somewhere in the converters causing the ...
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2answers
49 views

Can this receptacle power this power supply? [closed]

My car has a wall-style AC receptacle in it. It is merely marked 110V 150W. It is not mentioned in the owner’s manual. I’m curious if it can safely power this laptop power supply:
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0answers
65 views

PFC boost converter is not stepping up the voltage

I am making a PFC circuit for AC-DC converter. I am facing a weird issue. As per my design the output of the circuit should be 390VDC, but I am getting 311VDCrms with ringing (overshoot 360V, ...
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4answers
999 views

Converting 8V AC to 8V DC - bridge rectifier gets very hot while idling

I am tinkering with an Arduino and recently had to convert 8V AC to 5V DC in order to run it. The project is a custom doorbell, which gets the power from the doorbell transformer (transformer is ...
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0answers
35 views

AC adapter won't power fan at full speed [duplicate]

I have a spare 92mm case fan rated 12V and ~600mA I've used to build a solder fume extractor. When I was prototyping it, I tested the fan with a 12V 2.5A AC adapter and it worked fine, ran at full ...
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0answers
79 views

Astable 555 used for AC to DC Halfwave to DC stable conversion, is what I have done correct?

I have this falstad-circuit: And here it is per request, as a SCH file screen: I'm trying to use a 555 astable to convert a variable AC with maximum of 12V (coming from Bicycle Hub) to 8VDC, ...
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0answers
64 views

Use Triac as SMPS to get DC voltage

I want n 12V 1A supply for a project. I want a transformer-less topology. I was reading and experimenting with readily available traic based dimmers. They use phase control to cut the input voltage ...
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2answers
276 views

How to find the right smoothing capacitor for rectification circuit

I am creating a power supply which will need to convert the 24vac to 5vdc. I am thinking of using a rectifier to convert ac to dc, then a capacitor to smooth out the voltage, then an LM2596-5 to drop ...
3
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3answers
271 views

Why aren't non-isolated DC-DC converters made for high wattage applications?

I am new to electronics. I am presently studying DC to DC converters. One thing I noticed is that most of the people are using isolated stepdown converters like half bridge, full bridge, or resonant ...
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1answer
80 views

(230v)AC-DC(12v) wall adapter flashes when connected to dc to dc buck converter [closed]

So I used a common 230vAC to 12vDc (1AMP) wall adapter with dc jack like this and converted to 5v using a dc to dc buck converter same as based on lm2596s But the adapter LED starts blinking (...
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1answer
238 views

SMPS 5V without load, fluctuation on load TOP258PN [closed]

I am using PI Expert Online (this) to design a smps circuit for 5V, 2.5A output. I already have TOP258PN IC with me so built circuit for that. Change from schematics: I am not using choke and using ...
4
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4answers
447 views

Is DC-to-DC (24 V to 12 V) buck conversion typically more efficient than AC-to-DC (110 V to 12 V) conversion? [closed]

While building an online UPS system, I'm basing the choice to eliminate as many AC inverters from the system as possible because of the assumption that DC-to-DC conversion is more efficient than AC-to-...
2
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3answers
109 views

Please help me understand how to add AC power to my DC device

I have a device that runs off of three D batteries. I would like to be able to add a power cord so that I can plug it into the wall and run it off of that instead. I would also like to still be able ...
3
votes
1answer
141 views

Different Wattage Solar Panels for Home [different Voltage/Ampere]

My current solar system for home 12V 100W polycrystalline Solar Panel. 12V 75Ah Lead Acid solar tubular Battery. PWM 12V 10A Solar Charge Controller. 12V Input and 200VA Output Inverter. Current ...
1
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2answers
179 views

Power drop on AC-DC converter due to relay

A uController circuit is powered with an AC-DC converter. This circuit in turn acts on some relays to turn on and off some loads. We have two bi-stable relays and another simple relay (Omron G5DN-1A) ....
2
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4answers
173 views

300VDC to 24VDC voltage converter - Cheapest implementation

In an application, 100+, 100W 24V halogen lamps need to be individually controlled and run simultaneously. They stay on for a few seconds at a time and need to have very constant irradiation. ...
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2answers
64 views

How to insulate DC from earth noise while keeping it referenced to it

I have an AC/DC converter (220 to 24) inside an electrical cabinet. The 0VDC is referenced to earth, like this (couldn't find a symbol for an AC/DC converter in the schematic editor so I made a dirty ...
1
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2answers
106 views

AC “chopping” power supply inrush current problem

I've made a simple AC to DC chopping/switching power supply circuit (I'm not sure if it's called that) as shown below. in the left part of circuit (which is the gating/chopping part) when the ...
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2answers
75 views

3.3v Powersupply

I have been needing a 3.3 volt power supply that can use at least 12-24 volts ac dc in. I have looked online and managed to make this schematic but I have no idea if it works. I was hoping if you ...
2
votes
1answer
227 views

Why would this Class D Audio Amplifier have low current draw?

Disclaimer: Saying I have very little knowledge of electrical engineering theory is an overstatement. I very much appreciate your help and patience. I'm not finding any questions similar to mine, but ...
0
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1answer
934 views

Is it safe to use a 19V DC adapter for a 12V input if it can provide enough watts? [duplicate]

I have a small TV which expects 12V DC at 34W. Can I use an adapter with a higher voltage rating (19V for example) as long as it can provide enough amps to satisfy the amount of watts needed by the TV?...
0
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2answers
118 views

Am I safe working with a power supplier of 12 DC connected to the AC wall socket main line?

I'm working on an electronic home experimental project. But I have always been afraid of the issue of electricity since it can electrocute. My question is.. Am I safe working with a power supplier ...
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2answers
90 views

Transformer in 127V AC - 5V DC Converter

There is a transformer in this 127V AC to 5V DC Converter. I am trying to get one of them. But I don't know what kind of transformer is and I am unable to find it in my city. Also, it is so small. ...
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0answers
43 views

SMPS topology for combination of current controlled rail and fixed voltage rail

I'm looking at designing a LED driving power supply that can interface with a universal AC main input (~90VAC-260VAC) and produce 2 rails at the output; one a current controlled rail, and the other a ...
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1answer
173 views

How do I choose appropriate fuse for my circuit?

I am currently using a AC-DC adaptor with specs: AC-I: 100-2040V~50/60Hz 1.6A DC-O: 12V 5A Which is powering up 8 DC motors, 4× 12V 6W 4× 12V (wattage not specified, the motor is meant to be ...
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4answers
187 views

How can I run my e-bike wheel on AC power?

I have an electric wheel designed for an electric bicycle conversion. By my understanding, the wheel is essentially a 48V, 1000w rated brushless DC motor. It comes with a thumb throttle and kill ...
0
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1answer
141 views

Gigabit detection DIY

Ethernet up to 100Mbps uses only 2 of the 4 twisted wires in an ethernet cable while gigabit is using all of them. Connecting an LED to one of the gigabit-only pairs should therefore make it easy to ...
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0answers
229 views

Reducing AC/DC adapter (SMPS) output voltage

I have a AC/DC adapter P-1650-22 (used to power a notebook) laying around. I would like to use it for other purposes, i.e. as a constant voltage source for LEDs. The problem is, that the output ...
2
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4answers
238 views

Converting Christmas Village from DC to AC

So this was the year we bought a AC-powered O-gauge Lionel train and a battery-operated village to add to our Christmas tree decor. The problem, the village eats batteries like a kid eats cookies. ...
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2answers
119 views

Is Cadence unable to simulate AC to DC converters using simple full bridge rectifier?

I've tried several different topologies, such as the full bridge rectifier and the following which I've successfully tested on other simulators. However, on Cadence I always end up getting static ...
0
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1answer
214 views

What components do I need to add to the power circuit for this ESP8266 project?

I'm planning to make some controllers for each of the electrical heaters in my house. The heaters use a pilot wire to control their mode of operation: I'm following this project to control the pilot ...
0
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2answers
147 views

Design an AC/DC Nonisolated Switching Mode Power Supply

I'm designing a fifth generation pcb for my project and yet I stumbled across another design problem. First of all, the circuit and all components are enclosed from the environment and users (because ...
0
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1answer
57 views

What is the best starter adjustable power supply for pretty cheap (preferably ac/dc) [closed]

Please I am just a kid no $8953739857239875 power supplies. Btw I am an inspiring electrical engineer and I'm 10 so I need a bit of help so I don't how do I put this nicely, ahem trip the breaker if ...