# Diode bridge

#### Overview

This is a diode bridge. It converts alternating current (AC), into direct current (DC). The circuit is set up so that current is always flowing towards the input of RL, and away from the output. More information about the properties of diode can be found here:’https://tphelectronics.com/2015/09/29/diodes/

AC signal output is most commonly just connect to ground (0v).

RL represents the circuit to which you’re applying the DC voltage.

#### Signal diagram explanation

This shows one full oscillation of the AC signal at the input. Whilst the signal is above the horizontal line, the voltage at the signal input is positive. Whilst the signal is below the horizontal line, the signal input is positive

#### Flow of current during positive half of the oscillation.

During the section labelled ‘Input is positive’, here’s how the current flows around the circuit:

The reason why the current can’t flow through D4, after passing through RL, is because D4 has already been reverse biased by current flowing from the AC input.

#### Flow of current during negative half of the oscillation.

During the section labelled ‘Input is negative’, here’s how the current flows around the circuit:

#### Conclusion.

As you can see, regardless of whether the AC input is positive or negative, the current flowing through RL never changes. If we could see what the current looked like at RL, It’d look something like this:

Notes for future.

I’ll add in a diagram and explanation as to how to dampen the rippling effect seen in the graph above.

## 22 thoughts on “Diode bridge”

1. Might want to throw some capacitance across the output to tame the ripple in current.

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• I randomly threw this post up here with just the image last night. I don’t know why it’s gotten so much attention since then :’)

But yes, I’m going to add another diagram with a capacitor across the inputs, to act as a reservoir and text explaining it. You are 100% correct, and I’ll get to that soon.

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• What size capacitor would you use with a +-5v AC input?

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• Use this formula: Vripple = Iload / 2 f C

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2. I think it doesn’t work
Input should be fed in at one diagonal and output should be drawn at other diagonal

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• I double checked using multiple sources, and this is correct. So yes, it should work.

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• How it works

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• During positive cycle it passes though diode bw input and output

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3. It’s not working I’ve checked it

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• I hope that this post is clear and works for you now.

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• Yes bro this works, but the previous doesn’t

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4. This diagram is really unclear and confusing. Let me update it first.

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5. Where are you from?

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• England. What about you?

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• Nice, which part of India?

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• South India

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• Telangana state

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• From which university r u from?

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• It really annoys me that you can’t reply to a reply on here. I’m not currently in university, but I’m applying at the moment. I want to do electronics and communications engineering at kent university, if you’re interested.

Are you currently studying at university?

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• I have completed my engineering

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