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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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SMPS 5V without load, fluctuation on load TOP258PN

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
332 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-...
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3answers
96 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
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1answer
68 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 ...
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2answers
105 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) ....
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4answers
154 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
59 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 ...
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2answers
74 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
67 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 ...
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1answer
76 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 ...
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1answer
94 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?...
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107 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
67 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
34 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
42 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
111 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 ...
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1answer
135 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
94 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 ...
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4answers
161 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
66 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 ...
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1answer
141 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 ...
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2answers
69 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 ...
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1answer
53 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 ...
2
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1answer
259 views

Function of the Third Pin Inside Laptop Barrel Connector

So I've been doing research on barrel pin connectors, and have been trying to apply this knowledge to understand laptop barrel connectors, specifically. My confusion relates to the function of the ...
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3answers
77 views

Changing AC amplitude and frequency

I'm working on a project for school to monitor a 6 and 15 VAC signal coming in at 11KHz for both. I'm trying to find a simple way of recreating that at home for running some tests on circuits I'm ...
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1answer
46 views

How to size transformer for a circuit?

I am using a 5 Watt PCB mount AC/DC power module with universal input(85-264 V) and output as 12 V. The cost of the module is very high so thought if we could replace the module with a PCB mount ...
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2answers
130 views

What should I buy to test whether my DC power supplies are able to provide their rated power? [closed]

I recently bought an aftermarket AC-DC power supply for a laptop which was woefully defective. When connected to a Chromebox, a boot message appeared indicating that the supply could not provide ...
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2answers
171 views

DIY electromagnet using copper wire and AC adapter

I want to make for some demonstration (caching some paper clips on ON and doping them on OFF) electromagnet made from copper wire (should it be single wire?) with ferromagnetic inside coil: As power ...
0
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1answer
94 views

Simple AC to DC converter: upper limit for the capacitance of filter capacitor?

By 'simple AC to DC converter' I mean the familiar circuit shown in the figure below, where the capacitor C reduces the ripple. A sufficiently large capacitor can be used in order to reduce the ...
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1answer
42 views

Non-isolated DC power distribution for an appliance

I am building an appliance where we have a device where we need to have a +48 V/300 W DC power rail and a +24 V/300 W DC power rail. The AC (mains) should be world-compatible (both low- and high- ...
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1answer
62 views

About Ac to DC convertor..? [closed]

Which is the best way to convert Ac to DC , with maximum efficiency possible by using a transformer. The required voltage is 5v and current is 1a . I saw a circuit from my mobile phone charger they ...
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39 views

Fuses on both lines of an isolated AC/DC converter

I'm redesigning a board made from another person. This board have several AC/DC converters (like Traco TMP07 Series and similar) and some screw connectors to connect external devices. Neither the ...
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1answer
68 views

What products can be used power LEDs from an wall outlet? [closed]

I am currently working on a project that will be a type of night light that plugs straight into a wall. What parts can I use to convert the wall outlet voltage into that which can be used by a couple ...
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2answers
62 views

What is a Kva in simple terms, for somebody who doesn't know electrical engineering?

I have a DC circuit that runs on 8.1 A × 12 V (97.2 W). Power is supplied from a AC-DC transformer that plugs into a socket. How many of these can I run in a place that provides a maximum of three-...
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2answers
69 views

Splitting a 10amp 2.1mm DC barrel into positive and negative

I have this AC to DC converter and I want to be able to split out the positive and negative wires from the barrel without cutting off the barrel. I've been looking at options such as this jack to ...
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1answer
56 views

ATX 12V power supply fan required or not at low current?

Does ATX power supply really need its cooling fan when drawing only 3A at the +12V rail? I know that the fan is mandatory when it's running a computer that draws 200 Watts and above but is the fan ...
6
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1answer
720 views

Replace x2 capacitor with polyfilm? [closed]

I have a 12 V power supply that's not working anymore, so I opened it up and checked for faulty components with a multimeter, and I found two of them so far. One was a 1000 µF 25 V electrolytic which ...
2
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2answers
127 views

Limiting Inrush on AC/DC converter

I created a simple power supply as shown below that results in an unregulated 50VDC which is what I desire. The transformer is rated for 1000VA. It works ... but only if you're lucky enough to turn it ...
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0answers
91 views

Need help selecting a transformer for an AC/DC converter

I'm working on a pinball project that requires a 50VDC voltage to drive solenoids. The biggest load comes from the flippers (which both could be activated simultaneously) however it's possible for ...
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2answers
164 views

Why does my LM317 give lesser output than with LM337?

How can I maximize the ouputs?
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1answer
332 views

Understanding LED driver circuit AC to DC conversion

I am recently working on mains socket outlet type LEDs lights. They all have very similar AC to DC conversion circuit. simulate this circuit – Schematic created using CircuitLab C1 is a X-2 ...
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2answers
478 views

How to design a AC-DC circuit using only the hot/live wire has power input?

I was looking at these new IOT devices coming from CN that are designed to replace your standard wall switch with an ESP8266 smart-switch. It seems there are two types: A) the typical one where the ...
0
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1answer
364 views

N-Channel Mosfet has full Voltage on all Pins (IRFZ44N)

I recently wanted to use a IRFZ44N N-Channel Mosfet (up to 50V) to control a 50 LED Panel with a current of 35V. The Panel itself uses 230V AC which goes to a rectifier (?) which outputs 35V DC and ...
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1answer
52 views

DC signal to Integrated signal

I'm so new in analog electronics. So I stuck with one issue. Let's say I have an input signal, like blue one: To get a DC form I can rectife it (got a grip on it). But what I need is a smooth(...
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3answers
624 views

Can I get a 150V DC output LM317HV-MIL

Can I get a 150V DC output from the circuit below by using LM317HV-MIL? As the voltage input I will be using a 160V unregulated input voltage from a rectifier. If so, is there anything that I have ...
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1answer
183 views

How do some phone chargers raise their output voltage when loaded?

I got a Samsung phone charger some time ago. The text on it says 5.3V/2.0A, and when I plug a USB meter on it, the meter reads 5.3V 0.0A. The meter itself consumes a maximum of 0.02W (so 0.004A - safe ...
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1answer
414 views

AC/DC power supply: help to choose fuse, varistor and/or TVS diode

I'm going to use this 12VDC AC/DC power supply . It is the first time that I am going to use one and I have some questions about over voltage protection and peak current protection. These are the ...
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4answers
4k views

How do phone chargers have variable input voltage with constant output voltage?

My basic understanding is that a transformer can step down a voltage by the ratio of the primary and secondary windings, since this is a ratio the output is not constant. Thus my question is, how ...
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0answers
73 views

DC120v motor RF remote (for Dumbwaiter)

I have an AC120v winch(WARN ser.#80010) that converts to DC120v via a 50 amp bridge rectifier. Motor is brushed permanent magnet. The controller is 2 button reverse polarity pendent type that carries ...
0
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1answer
92 views

Power Supply for two 50V/12.5A Solenoids

I'm in the planning stages of building a custom pinball table and one of the sticking points is powering the flipper coils. They're 50V DC coils with a resistance of only 4 ohms during the stroke. ...