# Questions tagged [rectifier]

These are part of AC to DC conversion. A half-wave rectifier keeps only the positive part of the signal. A full-wave rectifier also keeps the negative part, but flips it to make it positive too.

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### Is full wave rectifier better than half wave one?

I am curious if there are practical differences between a DC power supply based on a half wave rectifier or a full wave rectifier. I mean I have a few small DC power supply units which should give ...
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### Full-wave bridge rectifier with capacitor filter and ripple voltage

According to various sources, the ripple voltage of a full-wave bridge rectifier is $$V_r = \frac{V_s}{2}fCR$$ where $V_s$ is the peak of the input voltage source, $f$ is the frequency, $C$ ...
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### How to convert AC to DC

I am designing a circuit that needs to output 5VDC @ 1A. I'm trying to use a wall transformer to step the voltage down to 12VAC. The next step is the diode bridge and ripple capacitor. The ripple ...
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### if a standard three-phase 400V AC connection is rectified what DC voltage comes out of it?

If a standard (in Europe and a large part of the world except North America and Japan) three-phase 400V AC (three lines having 230V RMS voltage if measured to neutral each) mains supply is rectified ...
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### why do rectified voltage boosts after adding a capacitor?

So I found this 9V 1A AC power supply laying around and decided to make a DC source. I rectified and added a capacitor to make things a bit even. After adding a capacitor my voltage boosted from 9V ...
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1 vote
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### High voltage power supply

We are given this schematic diagram, that our teacher called a high voltage power supply, then test the voltage of each capacitor. Why is the voltage at C1 half of the voltage at C2 and is the ...
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### Precision high speed peak detector

As a follow-up to my previous question, where I seek to determine the amplitude of a 2 MHz sine wave, I've settled for an op amp based solution. To recall, my input has a maximum 240 mV amplitude -- ...
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### Serial capacitors in electronic ballast of a fluorescent lamp

Recently I repaired one broken electronic ballast of a linear 30W fluorescent lamp. Now it seems to be working as expected, but I had to make some changes to it and I'd like to ask if you see any ...
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### Why AC supply is rectified first before stepping voltage down?

I have opened one of my phone chargers and was trying to understand how it works.. I found IC MB6F just at AC input which came out to be a bridge rectifier. My question is why AC is first rectified ...
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### Bridge Rectifier Fails When AC Inputs are Shorted

I am working on a design that involves powering a 3.3V microcontroller off a doorbell transformer but I am running into an issue with the bridge rectifier failing when the AC inputs to the rectifier ...
22k views

### Half-wave rectifier and RMS value

I have built a half-wave rectifier with a 5V peak sine input, 1kHz. In theory the RMS of the output should be 5V/2 = 2.5V, but the oscilloscope only measures 2.01 V. What could be the reasons for such ...
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### Connecting center-tapped transformer to earth ground; or, why am I being electrocuted?

Silly question here. I've wired up a full-wave rectifier using this dual-secondary transformer. If you want to check my wiring, I connected red-to-orange to "create" the center tap (I assume this is ...
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### Why does this bridge rectifier claim to have no diode forward voltage drop?

I was, "OK, this is feasible," but then I traced how it worked and it simply blocked current through drain and source when a P and N pair are reverse biased. When the other P and N pair are ...
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### How does this rectifier work?

In a car battery charger, I found a strange rectifier. Can someone explain to me how does it work? Here I have a transformer which is unmarked. By measuring resistance between its output terminals, ...
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### Simple $12V_{AC}$ to $12V_{DC}$ Rectifier

I want to convert a $12V_{AC}$ power supply output to use $12V_{DC}$ to power some outdoor LEDs. The power supply as it stands will light the LEDs (with a slight flicker from the reverse ...
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### Why do we use bridge rectifier?

If we already having a center tap rectifier with just two diodes doing the same work then why is there a need to use four diodes or the so called Bridge rectifier.
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### Bridge rectifier in parallel?

Is it possible to safely double the current limit using 4 bridge rectifiers? In one forum I found someone wrote: Use four bridges, one for each leg. Tie the AC input (cathode to anode) ...
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### Full wave rectifier vs full wave bridge rectifier

What is the difference between the full wave rectifier and the full wave bridge rectifier? In other words what do we gain if we use the bridge? As far as I know both do the same thing while the bridge ...
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### What is the purpose of parallel RC network in the bridge rectifier output?

Can anybody explain the necessity of the RC network shown in the figure. I found this in circuit for a logic power supply using Fly-Back converter?
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### Why is the negative terminal connected to both transformers in this half-wave rectifier?

I found the image below in an old book about vacuum tube rectifiers. Could someone explain why the negative terminal of the load is connected to the 6.3V transformer? I understand why it would be ...
5k views

### Storing the charge from a MOSFET Bridge Rectifier

I am using the following MOSFET Bridge to harvest AC bursts, that come from an electromagnetic transducer. In front of this circuit is a supercapacitor I have added. I read the following on a ...
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### Precise Full-wave rectification

I've been for quite some time now, trying to create a precise full-wave rectification of a signal coming from a CT sensor SCT-013-030. Here's the circuit: simulate this circuit – Schematic ...
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### Does a bridge rectifier care that much for AC frequency?

As I understand it, a bridge rectifier is a set of diodes that play a trick of logic that keeps the polarity positive. So, within the context of a household DC transformer does it matter what the ...
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### Why are home appliances and other devices made to operate on dc? [closed]

Why are home appliances not designed to work on ac?why cant we just stepdown the incoming 230V and design the systems to operate at low ac voltages,instead of converting ac to dc?
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### Formula for efficiency of half wave rectifier

I came across this formula for rectification efficiency of half wave rectifier: η= (40.6 *resistance of load resistor )/ (resistance of load resistor+ resistance of secondary of transformer + ...
1 vote
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### Measuring an AC-voltage at the ouput of a full bridge rectifier

I've a full bridge rectifier and I put the following function into it: $$5\sin(100\pi t)\tag1$$ So, at the output I get: $$\left|(5-2V_d)\sin(100\pi t)\right|\tag2$$ Where $V_d$ is the voltage ...
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### How to calculate efficiency of a rectifier with a capacitor filter

I was reading on rectifier circuits and I found out the efficiency of a center tapped transformer is the average power Pdc divided by the rms power Pac and if the resistance of the load is known then ...
2k views

### current through the smoothing capacitor in bridge rectifier

Can any one tell the reason for the current through the smoothing capacitor to be pulsating in the full bridge rectifier. I have attached the screenshots of the circuit and the wave form obtained in ...
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### What do we use to convert AC to DC current in houses

Do we use an active or passive rectifier to convert AC current to DC current, and why?
243 views

### Which is better - series or parallel rectifier? [closed]

The idea for this question gave me the question Understanding positive and negative rectifiers. Here I want to summarize the ideas behind the two circuit configurations - series and parallel, hoping ...
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### What are the advantages of full wave bridge rectifier with capacitors parallel to diodes?

I found a circuit where in the classical Graetz rectifier capacitors were added in parallel to each diode. It looked something like this: After the rectifier itself, there was the usual huge ...
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### AC to DC without transformer. How does this thing work?

I disassembled a Chinese-made flashlight and found they use just capacitors to bring down the voltage instead of a transformer. They are using it to charge small lead-acid battery. My question is how ...
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### Why don't more devices incorporate full-wave rectifiers as reverse polarity protection?

Recently, I was introduced to the idea of using a full-wave rectifier, in order to protect against reverse polarity damage in DC devices. I hadn't even considered using a rectifier in an already DC ...
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### If multiple sources are parallel with the diode, why does the one with a higher voltage turn on?

I've found this combination in many devices—for example, power supply redundancy modules, Ethernet-powered devices (PD of PoE), and RTC in circuits. In this circuit, the voltage source with a larger ...
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### 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 ...
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### No germanium diode available for small crystal radio -- can active components handle the task?

I know that germanium diodes are trivial to find online, but as this is for a demonstration I'd rather not spend \$6-7+ on shipping for a single 5 cent part for a project that's academic in exercise ...
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### What is the maximum frequency a bridge rectifier can handle?

I was designing a basic power supply with frequency ranging from 50-60Hz and thought about using this bridge rectifier KBPC50005. I cant seem to understand the range of input frequencies it can take, ...
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### Center tap split supply question

Lest's say that I have the following setup: a split supply (using two voltage regulators: a positive and a negative one) connected to a center tapped transformer (12-0-12). The output of the ...
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### Driving Permanent Magnet DC Motor via PWM

SUMMARY: I am currently trying to finish up a DIY project I've been working on for a while: Building an electric potters wheel. I acquired a treadmill and salvaged quite a few good parts from it, and ...
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### How does one compute the ripple currents seen by a rectifier filter capacitor?

Suppose one is designing a full-wave rectifier bridge, with a known maximum current load, and a known input inductance. Assume three-phase for this example, though the same concept applies to single-...
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### Op amp rectifier : transfer function and output impedance

I'm working on an EE student project which uses a rectifier to keep the peak value of a sine wave. You can find a PSpice pic of the schematics below (Ve is the input (1kHz), Vs is the output). Op amp ...
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### Determining amplitude of a 2 MHz sine wave

I'm designing a class E resonant inverter at a switching frequency of approx. 2 MHz. I need to control the inverter so as to maintain a constant current at the load. My strategy would be to put a ...
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### Why sine wave not square wave?

Rectifying square wave voltage seems to give us DC directly without the need of a capacitor. so, why do we prefer sine wave over it? What would change if I powered any adapter (laptop adapter as ...
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### Understanding the characteristics of a LED driver

I would like to understand the characteristics of a LED driver I have at home. Here is a photo of the label: I never studied LED drivers before. This post, this article, and this document helped a ...
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### 3-phase Brushless Motor - Are Volts and Amps at (X)RPM equal/similar when used as Generator?

If I have a Brushless 3-phase motor that spins at 3000rpm when given 6.0A @ 20v (no load) will it produce 6.0A and 20v (or anywhere close) when used as a generator and spun at 3000rpm?? And i suppose ...
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### How to interpret diode-mode readings from a multimeter

I'm using this multimeter to examine a heat gun fan. The fan has four contacts placed in a circle (well in a square inside a circle). Two opposite each other are labeled ...
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### SMPS Design Transformer Core Selection

I'm trying to construct an SMPS power supply with 230VAC at 50 Hz input and 5.6V/2.5A output. Here is the schematic: The design was optimized with EE19 core selected and I am expected to optimize the ...
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### 230V to 12V step down transformer

I'm making a water level indicator using an 89C51 for which I need 5 V input voltage. I used a 230 V to 12 V step down transformer and a regulator to get 5 V. I got the 5 V but then the transformer ...
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### Using normal diodes to rectify high frequency waveforms

Recently I was try to rectify the output of an “electronic transformer” using an ordinary rectifier diode 1N4007. The output of this device is bursts of frequency around 50kHz, with an envelope of ...
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