Loss of power over junctions

In summary, the conversation discusses the topic of power loss and voltage drop in electrical trains and motors, particularly in regards to junctions made with movable parts and brushes. The use of carbon/graphite brushes and coil-shaped hair springs is mentioned as possible solutions, with a two turn coil of metal tape or 0.010" brass shim also being considered. The conversation also touches on the use of flexible conductors and the trade-off between space and efficiency in different solutions.
  • #1
Jarfi
384
12
Good day. I was wondering what the extent of resistance/voltage drop occurs over junctions that are made off movable parts and brushes. Electrical trains tend to get the voltage from brushes so it can't be too great, also brushed motors.

In my case I was planning to run an electric brushless motor, but it is situated on a moving part, so either it was making long wires that can bend and twist a little, but that takes some space which would make my mechatronic machine larger. But then ofcourse I figured a simple coal brush or whatever like they use in brushed motors, and since this moving part will be moving far less, slower then in a brushed motor, it should last, my only concern left was weather there was a great amount of power loss in the junction between the brush and the moving part.

I made a quick sketch of the concept, the moving part moves +/- 30 deg, around an axis.
 

Attachments

  • brush.JPG
    brush.JPG
    21.1 KB · Views: 396
Engineering news on Phys.org
  • #2
Assuming you don't get arcs, it is just a regular resistor: P=I^2*R
Lower currents (and therefore higher voltages for the same power) are better, but can lead to problems elsewhere.
 
  • #3
A carbon / graphite brush will be less reliable and more bulky than a coil shaped like the hair springs in a meter.
You can wind say a two turn coil of metal tape to carry power to the moving part.
I would consider cutting strips of 0.010” brass shim from a model shop. Size will depend on power.
Avoid passing current through metal bearings. It is better to use an extra flexible conductor.
 
  • #4
Baluncore said:
A carbon / graphite brush will be less reliable and more bulky than a coil shaped like the hair springs in a meter.
You can wind say a two turn coil of metal tape to carry power to the moving part.
I would consider cutting strips of 0.010” brass shim from a model shop. Size will depend on power.
Avoid passing current through metal bearings. It is better to use an extra flexible conductor.

Thanks for the input,

I tried to get a mental picture of this but couldn't with my current education. Is there a name for what you are mentioning? Id gladly study a better solution than a carbon brush.

Also, a flexible conductor is a possibility, that is how the original concept was. I then recently have been leaning over to brushes due to advantages on size, a brushed solution takes less space then a flexing wire, my original concept had empty spaces for wires to move around in.

Brushed solution: possible power loss but less spacious

Flexing wire solution: efficient but space and engineering difficulties.
 
  • #5


Thank you for your question. The amount of resistance and voltage drop that occurs over junctions in electrical systems is dependent on several factors, including the materials used, the design of the junction, and the amount of movement or wear that occurs.

In the case of brushed motors, the brushes themselves can cause some resistance and voltage drop due to their contact with the commutator. However, this is typically minimal and can be managed by using high-quality materials and proper maintenance.

For your proposed brushless motor on a moving part, there may be some additional resistance and voltage drop at the junction between the brush and the moving part. This can be mitigated by using high-quality materials and designing the junction with minimal contact resistance. Additionally, as you mentioned, using a slower moving part can also help reduce wear and prolong the life of the junction.

Overall, while there may be some power loss at the junction, it is likely to be minimal and can be managed with proper design and maintenance. I hope this information helps.
 

What is "Loss of power over junctions"?

"Loss of power over junctions" refers to a phenomenon where the ability to control or make decisions about a certain junction or intersection is diminished or taken away entirely. This can occur due to a variety of factors such as changes in government policies, technological advancements, or shifts in power dynamics within a community.

What are some examples of "Loss of power over junctions"?

Some examples of "Loss of power over junctions" include: a government implementing automated traffic signals at an intersection, taking away the ability of local officials to manually control the flow of traffic; a community being forced to accept a new road or highway project without any say in its design or location; or a city implementing a new zoning plan that limits the control of property owners over their own land.

How does "Loss of power over junctions" impact communities?

The impact of "Loss of power over junctions" can vary depending on the specific situation and community. In some cases, it may lead to frustration and discontent among community members who feel their voices are not being heard or their needs are not being considered. It can also result in changes to the physical landscape of a community, potentially altering the character and functionality of certain areas.

What can be done to address "Loss of power over junctions"?

Addressing "Loss of power over junctions" can be a complex and multifaceted issue. Some potential solutions include advocating for more community involvement in decision-making processes, implementing policies that prioritize community input and feedback, and utilizing technology and data-driven approaches to create more efficient and equitable junctions.

How can researchers and scientists contribute to understanding "Loss of power over junctions"?

Researchers and scientists can contribute to understanding "Loss of power over junctions" by conducting studies and collecting data on the impacts of these changes on communities. They can also analyze and evaluate different policies and solutions to identify the most effective ways to address this issue and mitigate any negative effects it may have on society.

Similar threads

Replies
11
Views
3K
Replies
1
Views
782
  • Electrical Engineering
Replies
20
Views
2K
  • Electrical Engineering
Replies
12
Views
1K
Replies
5
Views
4K
  • Electrical Engineering
Replies
9
Views
2K
  • Electrical Engineering
4
Replies
136
Views
15K
  • Electrical Engineering
Replies
23
Views
4K
  • Electrical Engineering
Replies
3
Views
6K
  • Electrical Engineering
Replies
1
Views
2K
Back
Top