Liquids Resistance

It provides a smooth and controlled starting torque by gradually reducing the resistance applied to the sliprings.

Far smoother than stepped resistance, but more expensive.

Can you give any material reference for better understanding about liquid resistance and stepped resistance? also How they influence in sliprings?

http://www.lmphotonics.com/ is a good place to start. Then search Google

Thank you for your reply.. Now i want to learn that.. If any doubt, I will post.. Please reply on that..

Regards,

Anguraj

I found this, a drawing I did for an apprentice many years a go

The liquid is just a medium for easily applying variable resistance. A set of resistors is imersed into a tank of electrolytic solution, which allows conduction across the gaps between them and the amount of resistance varies by how much of the surface area of the resistor is imersed. So by raising and lowering either the resistor or the solution, you can infinately vary the resistance in the circuit.

Crude but representative drawing from an old patenet (the web is woefully devoid of good images of this).

Thank you.. Your way of explaining regarding liguid resistance, I feel like just as in 3D imagination.. But your given diagram depicts some what clear.. It is very clear if you provide the numbered parts descriptions in the given diagram..Can you provide..?

The numbers on that drawing are related to the specific patent application, I don't have time to retype the entire thing. You can do a web image search for "liquid rheostat" and find it like I did, the image will link to the original page.

Tonys' drawing is another way to do it. There are as many ways to accomplish this as there are to skin a cat (American colloquialism meaning there is no right or wrong way to do it).