I need some help with half wave rectifier

bertus

Joined Apr 5, 2008
21,524
Hello,

Without a schematic we can not comment on your question.
A half-wave rectifier usualy has one diode.
See the attached PDF for more info.

Bertus
 

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Papabravo

Joined Feb 24, 2006
16,773
Yes, i need to make a presentation and I dont find anything about the second diode. There is nothing on the internet for a half have rectifier with 2 diodes.
There is a conflict between your description of what you want to build and the materials you are using. You still have not provided a schematic diagram, so we have no possible way to help you. Provide the diagram or accept your fate. Those are your choices as I see them.
 

Thread Starter

razvan23

Joined Mar 2, 2021
12
There is a conflict between your description of what you want to build and the materials you are using. You still have not provided a schematic diagram, so we have no possible way to help you. Provide the diagram or accept your fate. Those are your choices as I see them.
I dont have a diagram, it's my job to make one .
 

Papabravo

Joined Feb 24, 2006
16,773
I dont have a diagram, it's my job to make one .
I see. Then you should start by finding a diagram that is a half-wave rectifier with a single diode, spend some time to understand it. If you want to add a second diode, the most productive way to do that would be to add that diode in such a way that you make a full-wave rectifier. Anything else you do will just be foolish nonsense.
 

Thread Starter

razvan23

Joined Mar 2, 2021
12
I see. Then you should start by finding a diagram that is a half-wave rectifier with a single diode, spend some time to understand it. If you want to add a second diode, the most productive way to do that would be to add that diode in such a way that you make a full-wave rectifier. Anything else you do will just be foolish nonsense.
My teacher just gave the diagram
 

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crutschow

Joined Mar 14, 2008
27,697
That's not a standard half-wave power rectifier, it's a small-signal, half-wave precision rectifier, which is an entirely different animal.
If you Google that, you will find some info on it.
Since this is homework help, not homework do, you need to show us your attempt at answering the questions.
 

Papabravo

Joined Feb 24, 2006
16,773
This is a different animal entirely. It is not a power conversion circuit as would be the case for a Half-Wave rectifier. Since it involves an operational amplifier, it has a different purpose. I believe this is known as a Precision Half-Wave rectifier.

Words are NOT an appropriate method of communication when it comes to circuits. You should take this valuable lesson to heart and never rely on words alone to convey information about a circuit. If you have a means of simulating the circuit, that would be the best way to examine the operation.

Back to you original question. Do you understand anything about the operation of any of the components?

Here is a simulation of what it does. In order to understand this circuit you must understand what the opamp is doing. Do you?

See Post #15 for a screen clip of a revised circuit and the results of simulation
 
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Papabravo

Joined Feb 24, 2006
16,773
The TS's circuit has a higher value feedback resistor, so the output voltage will be different.
You're right I looked at his schematic and, since 40K is not a standard value, my brain just blew past it. My bad!
EDIT: I also upped the power supply voltage to avoid the distortion of getting too close to the positive rail with a gain of 4.
 

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Thread Starter

razvan23

Joined Mar 2, 2021
12
I asked if you knew what the purpose of the operational amplifier was. If you don't, that's OK we can help with that.
After i did my research about this type of circuit, i learned that we add the second diode to prevent the the op-amp going in negative saturation(in my schematic) if i am correct .
 

Thread Starter

razvan23

Joined Mar 2, 2021
12
This is my presentation about it.If you have anything to add please tell me. I dont know if I covered all the points (shematic, operation, the purpose of diodes D1 and D2, mathematical relationship, positive and negative output voltage, timing diagram. shematic, operation, the purpose of diodes D1 and D2, mathematical relationship, positive and negative output voltage, timing diagram).
 

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