Current sensing and standard resistor

In summary, Brandon has a 12v switching transformer that has one of the legs of a black brown silver gold 2w resistor broken off. He has been unsuccessful in finding a standard .01 2w resistor and has found a current sensing resistor at the values, but should it be used. The resistor in the power supply is ceramic, blue in color, and looks like the ones you would find in electronics store on the shelf. Brandon took some EE in collage but only remembers enough to be dangerous. He just wanted to be honest.
  • #1
I forgot ohms
7
0
I have a 12v switching transformer; one of the legs on a black brown silver gold 2w resistor is broken off. I have had zero luck finding a standard .01 2w resistor. I did find a current sensing resistor at the values, but should it be used. The resistor in the power supply is ceramic, I think, and bluish silver in color. Looks like the ones you would find in electronics store on the shelf but just not in .01.lol I took some EE in collage but only remember enough to be dangerous. Just wanted to be honest.
Thanks Brandon
 
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  • #3
Studiot said:
I doubt your resistor is 0.01 ohms.

Check again using this calculator

http://www.csgnetwork.com/resistcolcalc.html
That calculator doesn't have all the color bands for the multiplier. Here's a better image: http://www.google.com/imgres?imgurl...=X&ei=S7GHTdvGA4HerAHttuyzBg&ved=0CB4Q9QEwAA".

If it is a current sensing resistor, the resistance should be really small.

Are you sure the color code is black-brown-silver? Not not brown-black-silver (which would be 0.1 ohms, not 0.01 ohms).

If th current sensing resistor you have is the same resistance value as the one that broke, the only think that matters is how much current it needs to handle. A .01 ohm 2 W resistor can handle 14 A of current. Is your other resistor rating for that much?
 
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  • #4
the resistance should be really small.

(Really) small yes, 10 milliohms, no. That is the sort of resistance of a soldered joint so would be a waste of time for any soldered in component.

If 10 milliohms was necessary in the circuit it would most likely be formed from a carefully sized pcb track.
 
  • #5
It is black brown silver gold. I will check the specs on other resistor. My local distributor has access to five resistor manufacturer , and not a one offer. 01 ohm 2watt. Smallest I could find is .1 ohm 2watt. I guess I could parallel a bunch of .1 but don't have the space.
 
  • #6
The power supply is a 12-15vdc 15amp. We use them to power battery chargers and tire truer. I race 1/12 scale RC cars. The tire lathe is to cut down foam tires to achieve proper roll out.
 

FAQ: Current sensing and standard resistor

1. What is current sensing and why is it important in scientific research?

Current sensing is the process of measuring the flow of electrical current in a circuit. It is important in scientific research as it allows scientists to analyze and understand the behavior of different components in a circuit, and to ensure that the circuit is functioning properly.

2. What is a standard resistor and how is it used in current sensing?

A standard resistor is an electronic component with a known resistance value. It is used in current sensing as a reference point to measure the voltage drop across the resistor, which is then used to calculate the current flowing through the circuit.

3. How do scientists choose the appropriate current sensing method for their research?

The appropriate current sensing method depends on various factors such as the type of circuit being used, the desired accuracy and sensitivity, and the budget of the research project. Scientists may also consider the type of signal being measured and the potential impact of the sensing method on the circuit.

4. Can current sensing be used for both AC and DC circuits?

Yes, current sensing can be used for both AC (alternating current) and DC (direct current) circuits. However, different methods and components may be used for each type of circuit, as the behavior of current flow is different in AC and DC circuits.

5. What are some common applications of current sensing in scientific research?

Current sensing is commonly used in many scientific research fields such as physics, electrical engineering, and materials science. It is used to measure current in various types of circuits, including power supplies, motors, and electronic devices. It is also used for monitoring and controlling current in renewable energy systems, such as solar panels and wind turbines.

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