Average current in single phase bridge converter SCR

In summary, the conversation is discussing the concept of average load current in controlled rectifiers, specifically for full wave bridge rectifiers. The notes state that the average load current is Id/2, but the speaker is confused as to why the 2 is included in the formula and cannot find any resources mentioning it. There is also a discrepancy in the given answer for a question related to the topic. The conversation ends with confusion over whether the thyristor or load current should be divided by 2 for the average value.
  • #1
jaus tail
615
48
<< Mentor Note -- thread moved from the technical forums, so no Homework Template is shown >>

I'm studying controlled rectifiers and for full wave bridge rectifiers the notes(that I'm studying from says)
upload_2017-12-31_16-30-44.png

It says that the average load current is Id / 2
I don't understand how. Why should the 2 come in formula?
I tried searching in books but there wasn't any formula for average load current. Just average voltage.
There is also this question.

upload_2017-12-31_16-32-3.png

I'm getting answer as 6.66A
But they've given answer as 3.33A
Why will the load current be divided by 2 for average value? I realize this is homework but I'm sort of confused with the concept as to why is average load current divided by 2 in the formula and graph above.

I guess the thyristor current should be divided by 2 for average value. But why load current?
 

Attachments

  • upload_2017-12-31_16-29-18.png
    upload_2017-12-31_16-29-18.png
    7.6 KB · Views: 516
  • upload_2017-12-31_16-29-30.png
    upload_2017-12-31_16-29-30.png
    5.6 KB · Views: 527
  • upload_2017-12-31_16-30-44.png
    upload_2017-12-31_16-30-44.png
    31 KB · Views: 2,071
  • upload_2017-12-31_16-32-3.png
    upload_2017-12-31_16-32-3.png
    5.8 KB · Views: 733
Last edited by a moderator:
Physics news on Phys.org
  • #2
jaus tail said:
It says that the average load current is Id / 2
I don't understand how. Why should the 2 come in formula?
It's a little confusing -- could they mean the average load current for each pair of SCRs?
 
  • #3
They haven't mentioned anything. Just this question. And even in the formula they've said I(avg) = I(load)/2
And then they've stated formula for thyristor RMS current.
 
  • #4
Yep. I admit to being confused also. I also get 6.66 A which means we are either both right or both wrong. Let's know of your progess. Thanks.
 
  • Like
Likes jaus tail

1. What is a single phase bridge converter SCR?

A single phase bridge converter SCR (Silicon Controlled Rectifier) is an electronic circuit used to convert AC voltage into a DC voltage. It consists of four SCRs connected in a bridge configuration and is commonly used in power supplies.

2. How does a single phase bridge converter SCR work?

The SCR acts as a switch, allowing current to flow in only one direction. When triggered by a pulse from a control circuit, the SCR conducts and allows the flow of current from the AC source to the load. The SCR then remains conducting until the AC voltage drops to zero, at which point the SCR turns off.

3. What is the average current in a single phase bridge converter SCR?

The average current in a single phase bridge converter SCR depends on the load resistance, the supply voltage, and the triggering angle of the SCR. It can be calculated using the following formula:

Average current = (supply voltage / load resistance) * (1 - cos(α))

Where α is the triggering angle of the SCR.

4. How is the triggering angle of an SCR determined?

The triggering angle of an SCR can be determined using a control circuit that sends a pulse to the SCR at a specific phase of the AC supply voltage. This pulse triggers the SCR to conduct and determines the amount of current flowing through it.

5. What are the advantages of using a single phase bridge converter SCR?

Some advantages of using a single phase bridge converter SCR include its ability to convert AC voltage into DC voltage, its high efficiency, and its ability to control the output voltage by varying the triggering angle. It also has a simple and compact design, making it a popular choice for power supply applications.

Similar threads

Engineering How Do You Calculate Load Current Values in a Center-Tap Full Wave Rectifier?
    • Engineering and Comp Sci Homework Help
Replies
1
Views
856
Single Phase Full Wave Controlled Bridge Rectifier
    • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
Finding Turns Ratio and Average Current in the Primary Winding
    • Engineering and Comp Sci Homework Help
Replies
12
Views
4K
Half controlled single bridge rectifier
    • Engineering and Comp Sci Homework Help
Replies
6
Views
3K
Ripple frequency of three phase half bridge converter
    • Engineering and Comp Sci Homework Help
Replies
1
Views
3K
Why output waveform look like this in bridge rectifier
    • Engineering and Comp Sci Homework Help
Replies
7
Views
2K
Single Phase Controlled Rectifier Problem
    • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
3 Phase Systems Theory and Procedure -- Determining Average Power
    • Engineering and Comp Sci Homework Help
Replies
3
Views
2K
Engineering Calculating current and voltage of a rectifier circuit
    • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
How Do You Calculate Current in a Three-Phase System's Middle Capacitor?
    • Engineering and Comp Sci Homework Help
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top