Explanation on Shunt resistor from meter

In summary, a meter shunt diverts an exact proportion of the total current away from the meter, allowing for accurate measurement. This means that the meter reading is always proportional to the actual total current. It can be visualized by thinking of the meter as a resistor, and using Ohm's Law to calculate the current flow. However, it is important to be polite and respectful when seeking help or clarification from others.
  • #1
omerhassan
3
0
I know meter shunts are used to direct most of the current away from the meter coil but my question is if you direct most of current away from the coil, how is the meter measuring the current flow accurately.

Im kinda slow in the head so no complex fried banana explanation. tnx
 
Engineering news on Phys.org
  • #2
Can someone explain this to be quick, or are you all also slow in the head
 
  • #3
A meter shunt diverts an exact proportion of the total current away from the meter but also an exact proportion goes though the meter.

So, if it takes 1 amp to make the meter read full scale, it will take half an amp to make it read half scale. Similarly, the meter reading is always proportional to the actual total current.
 
  • #4
omerhassan said:
Can someone explain this to be quick, or are you all also slow in the head

This comment is unacceptable. You can say what you like about your own intelligence, but it is insulting and outside Forum rules to assume anyone who doesn't choose to answer your question is stupid.

Answering questions is purely optional.
 
  • #5
Vk6kro thank you, I don't mean stupid, I mean slow typers. But I still don't understand your explanation but thanks
 
  • #6
Suppose the meter takes 1 mA and has a resistance of 900 ohms.
When 1 mA is flowing, the voltage across the meter is I * R or 0.001 amps * 900 ohms or 0.9 volts.

If you put a 100 ohm shunt across the meter, then the current through the shunt for a full scale meter reading would be 0.9 volts / 100 ohms or 9 mA.

So it now takes a total of 10 mA to get a full scale deflection on the meter.

Can you see that it takes 5 mA to get a half scale deflection on the meter?
 
  • #7
Think of the meter as a resistor.

Surely you can solve how current divides between parallel resistors?Changing them to admittances helps visualize it.

Ohm's Law - it's more than just a suggestion.
 
  • #8
omerhassan said:
Can someone explain this to be quick, or are you all also slow in the head

That can only be taken as an insult. "In the head" doesn't refer to typing speed.
Afiac, you can solve your own problems. Your main one is to learn to be polite when you need to know something and to apologise when you have offended someone.
 

1. What is a shunt resistor?

A shunt resistor is a type of resistor that is used to measure the current flowing through a circuit. It is placed in parallel with the component or circuit being measured, and the voltage drop across the shunt resistor is used to calculate the current.

2. How does a shunt resistor work?

When current flows through a shunt resistor, it creates a voltage drop across the resistor. This voltage drop is proportional to the current flowing through the circuit, according to Ohm's Law (V=IR). By measuring this voltage drop, the current can be calculated.

3. Why is a shunt resistor necessary for measuring current?

A shunt resistor is necessary because most meters are not able to directly measure high currents. By using a shunt resistor, only a small portion of the current is directed through the meter, allowing for more accurate measurements.

4. How do you calculate the current using a shunt resistor?

To calculate the current using a shunt resistor, you need to measure the voltage drop across the resistor and the resistance of the shunt resistor. Then, use Ohm's Law (I=V/R) to calculate the current.

5. What are the advantages of using a shunt resistor?

Using a shunt resistor allows for accurate measurement of high currents without damaging the meter. It also allows for measurements to be taken in parallel with the circuit being measured, without interrupting the flow of current.

Similar threads

  • Electrical Engineering
Replies
4
Views
909
Replies
6
Views
897
  • Electrical Engineering
Replies
26
Views
6K
  • Electrical Engineering
Replies
33
Views
567
  • Electrical Engineering
Replies
1
Views
826
  • Electrical Engineering
3
Replies
77
Views
5K
  • Engineering and Comp Sci Homework Help
Replies
4
Views
1K
Replies
23
Views
2K
Replies
6
Views
1K
  • Electrical Engineering
Replies
20
Views
2K
Back
Top