# Bridge rectifier transfer function

Tags:
1. Apr 12, 2017

### Cocoleia

1. The problem statement, all variables and given/known data
I am asked to decide which one of these is the transfer function of a bridge rectifier

I was thinking D, but my friend says D is for when there is only one diode. Can anyone explain what the right choice is and why? This is not homework, rather preparation for my final.

2. Apr 12, 2017

### Staff: Mentor

You'll need to provide an attempt at solution along with your reasoning for that choice. What exactly are the graphs showing?

3. Apr 12, 2017

### Cocoleia

Well they show vout along the x-axis and vin along the y-axis. I suppose it would make sense for D to be for one diode, since it would only start conducting at 0.7, and after I assume the slope is 1 ?

4. Apr 12, 2017

### Baluncore

I assume the horizontal axis is a floating differential voltage input, and the vertical axis is the resulting floating differential output voltage while some current is being drawn by a load.

For a rectifier the output voltage will always remain above or below the x-axis.
There will be no output until there is sufficient voltage to turn on two diodes in the bridge.

The output transfer function could be (b) or (g) depending on the polarity of the output.
I would nominate (g) as it is a positive output.

Half of the figures are simple cases of reversing the input or output polarity convention. Apart from the bridge, there are forward and reversed diodes. There is also a pair of back to back diodes in parallel.

Now you should be able to go through the figures and draw a circuit using one, two or four diodes that will give each of those transfer functions.

5. Apr 12, 2017

### Cocoleia

Thank you, this is really clear now!!!