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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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2answers
71 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-...
2
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2answers
84 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 ...
0
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1answer
69 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
votes
1answer
747 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
votes
2answers
192 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
139 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 ...
0
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2answers
200 views

Why does my LM317 give lesser output than with LM337?

How can I maximize the ouputs?
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1answer
466 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 ...
0
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2answers
689 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
549 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 ...
0
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1answer
63 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(...
0
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3answers
910 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 ...
0
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1answer
216 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 ...
0
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1answer
501 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 ...
11
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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 ...
0
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2answers
132 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. ...
1
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0answers
64 views

Help in identifying two parts

I need to identify two parts that I need to replace, but I'm having a hard time doing it. These are the parts: Part 1: From my research I think it is a trigger switch (http://www.jiaben.com/en/pro....
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1answer
135 views

The book I want that you may know about Electrical Measurements [closed]

I'm looking for the book that online version could not be found on the internet. The book called Electrical Measurements: Examples and Problems, 116 pp., Nicosia, 1999. by Ismayilov, Khalil Abbasoglu ...
3
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2answers
408 views

Can I use a 20V or 24V to power up a piano that needs 21V? [duplicate]

The power adapter of the piano should be AC/DC 21V, 1.5A. But I can't find in a short time to buy something exactly like that, but I found this options: 20V, 3A or 24V, 3A Can I use one of this to ...
1
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1answer
95 views

Some questions about the RECOM RAC02-05SC AC/DC power supply converter

I'm designing a PCB and I want to use this AC/DC power supply converter. I have found this commercial PCB where they use it and I have these questions: I have seen that the PCB has some slots (see ...
0
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1answer
279 views

AC signal to switch on a DC circuit

I have a 12V DC circuit that I want to switch on/off, based on 8V AC signal. Can I do it with a diode connected to the gate of a transitor? EDIT: The AC circuit is a door intercom. I'm trying to ...
3
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2answers
887 views

Fuse for parallel AC/DC power supply

I am designing a system which will use two 12V AC/DC 60W modules (Meanwell IRM-60-12) I would like to protect the system using a fuse. In the case of a parallel design like the one below, should I ...
0
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1answer
618 views

Powering a motor through wireless electricity [closed]

simulate this circuit – Schematic created using CircuitLab simulate this circuit Schematic redrawn by Transistor. OP to edit or delete as required. I have a wireless electricity transmission ...
0
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7answers
3k views

Calculate the electric bill of a phone charger (AC adapter input or output?)

I need to calculate the amount of money I pay for charging my phone with this charger I know that I need to calculate the watts then kWh, so I multiplied 5 V by 1.55 A to get 7.75 watts and then use ...
0
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1answer
36 views

Hooking up AC/DC converter

the converter in question Hello for the converter in the link above when converting AC to DC should I have both inputs to the same AC source or do I just need one output connected? I have used the ...
0
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1answer
45 views

Back Up Battery System Design

So I’m trying to design an AC/DC convertor for a test unit that will go inside of an environmental chamber, but I’m also trying to build in a battery backup charger and switcher circuit, in the event ...
7
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2answers
7k views

Is it possible to step down 240 AC to 5 DC without transformer?

Microcontroller which is controlling mains voltage circuit requires 5 volts to operate. Is it realistic to use diode bridge followed by capacitor to straighten the ac wave and then use voltage divider ...
1
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2answers
1k views

ATtiny13a capacitive power supply

I would like to power my Attiny13a MCU with a transformerless capacitive power supply. The MCU itself needs only a few milli amps and it will drive 2 LEDs at 15mA each through it's digital pins. So I ...
2
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2answers
387 views

What is deciding the current of an AC to DC circuit

I'm a beginner, trying to build a power supply based on the sketch below to convert 230V AC to 5V DC. My final aim is to supply precision voltage for Arduino, which I think is 5V 700mA. Here is the ...
1
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3answers
2k views

DC plug pins. Which is positive?

I am trying to convert my old 9V battery operated Wah-wah pedal to a DC converted one, so I can use AC power. I bought a DC plug for it and was told that the center pin is for ground. However there ...
3
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1answer
178 views

How to get from 3 phase variable high voltage AC to 230V AC

I already asked all the electricians in my area (at least 7-8) and nobody could help me, so I am asking you. I have a Pelton generator - a type of water powered generator. My output is 3 phase ...
3
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2answers
430 views

What is a simple yet efficient way of converting 12VAC to 5-12VDC?

I am trying to create an LED pool light that works off a 12VAC input. Upon disassembling a similar pool light (Intellibrite), I found that they appear to be using rectifiers and perhaps a few small ...
0
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1answer
50 views

How to run / pilot this motor

I would like to be able to run this motor clockwise and counter-clockwise and speed control. I have 3 phase power 380 volts (AC) and this is a 110 V DC motor (max 40 amps). What is the correct type ...
0
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2answers
1k views

Simple circuit to detect ac power loss and use dc backup? [closed]

I want to make a simple circuit like those used in commercial emergency lights. I would have a "walmart" AC to DC adapter powering say a DC light or two. I would like it so when the AC powering the ...
1
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0answers
143 views

Power supply unit with two negative and positive outputs

So I am trying to add a power supply unit, which takes one input and supposed to provide one output: IN: 85-265V AC OUT:12V DC; 25A (max output power 300W) However, when I look at it, it clearly ...
8
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3answers
7k views

Bridge rectifier: 4 diodes vs. single chip?

I notice (among the DIY audio enthusiasts at least) that when it comes time to design a power supply for an amplifier, DAC or whatever that the parts list will inevitably include something like "4 x ...
0
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3answers
1k views

Can I quickly charge supercapacitors with a power adapter?

I am trying to make a super capacitor bank that I can charge is a couple minutes and it will output a 5v USB charge (aka a power bank). My materials: a 15v 8a power adapter, 2 Maxwell 2.7v 3000F ...
0
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1answer
74 views

Run 12 VDC micro-processor from 480 VAC power supply [closed]

I am trying to power a 12VDC (~3 amps) microprocessor module from a 480 VAC grid power. Can I use a 480 VAC to 24VDC (https://www.automationdirect.com/adc/Shopping/Catalog/Power_Products_(Electrical)/...
0
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1answer
22 views

Power output for Sager HVGC 65

I wish to get 12VDC @ 4 amps from Sager HVGC 65 Watt power supply. Datasheet: https://www.sager.com/_resources/pdfs/product/HVGC-65.pdf I have attached a picture of the datasheet. I would like to use ...
2
votes
1answer
428 views

AC-DC converter (230V - 5V) supply for microcontroller to control outlet

I have built a circuit using a PBO-3-S5, AC-DC circuit and applied some necessary components. iIn the description and when testing the circuit I get a 4.8V output voltage which should be enough to ...
2
votes
1answer
987 views

What's the difference between Clamper and Rectifier

I have a doubt that instead of rectifier we can use positive clamper to get the DC voltage at output, because the clamper adds the DC voltage to the AC signal, but even the same thing is done by the ...
0
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1answer
227 views

Regulate, convert to DC and store current from home made AC generator to charge laptop

I am working on a small experimental project, learning more and more about electricity and electronics. So, I have found this broken mixer and, surprisingly, it has a 300W engine with magnets that ...
1
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0answers
90 views

How much energy is lost between (solar panels+battery pack) & DC operated electronics due to conversion

For the sake of simplicty; I have solar panels generating Xvolt, Yamperage. All of the power will be used by Xvolt devices. But all of the house and device adapters are designed to use AC grid. So ...
2
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2answers
3k views

Full Wave Rectifier Efficiency

I was readings this article and extracted from it that "The maximum efficiency of a Full Wave Rectifier is 81.2%". Is that true, or alternatively is there some other fundamental limit on AC/DC ...
1
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1answer
134 views

Relay-controlled Fan Transient Question

Greetings guys and gals, I am seeing some odd behavior in my PIC-controlled circuit and need some help from the experts. I have a PIC18 at 3.3V turning on a bathroom vent fan via a relay. The fan ...
1
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1answer
99 views

Can I build a laptop like power supply for my PC with a car battery?

Power outages are quite common here(india) and I want something better than a UPS: I don't wanna shut down the system. I was quiet inspired by Make Your Computer UPS Last for Hours that uses a car ...
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2answers
214 views

Modify The Circuit

EDIT: I want to produce +12 Volts as well as -12 volts output. It would be very helpful if someone can suggest changes in component values keeping the structure same. Thanks in advance.
0
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1answer
95 views

Laptop powerbank, AC current [closed]

I want to buy a laptop powerbank which output AC current, in which I then plug the stock charger of my laptop. It it a good idea, or I should rather buy a powerbank that directly output 12v so I can ...
1
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5answers
2k views

capacitor power supply for 1 Amp output current

I'm trying to make a fairly small AC(220V) to DC convertor to power microcontrollers and some actuators. It needs to output a current of 1 amp to the load. I tried looking at using transformers, but ...
-2
votes
1answer
424 views

Close/Open circuit based on power supply to a relay [closed]

I am new here and to electrical world. I need to resolve a very basic real life issue. I have two fans in my bed room. One is AC and the other one DC powered by a lead acid battery. I want the DC fan ...