Recent content by mrkevelev

Good info here. Another related question: so if I know that a device is rated for an DC input voltage up to 12 V, and it doesn't mention current, as long as the voltage I give is 12 or less, then it shouldn't be damaged? What if I give it 12 V at a much higher current than it needs?

How is motor speed regulated (lets say a PM DC motor)? Is the voltage kept constant, and current increased/decreased, or is current kept same and voltage increased/decreased or both? What about torque and speed? Will giving a motor too much voltage or current damage it? I'm trying to...

Let's say I'm riding a bike at constant speed. Also assume that the person riding is rigid, no moving of the persons body, constant center of gravity. Assuming that there is sufficient friction between the tires and road. If I apply the front brakes, I will likely tip over. If I apply the...

Lets say there is a pulley attached to the ceiling. Hanging on the pulley is a rope and on each end is a 1000 lb. weight. I believe that theoretically it wouldn't take any torque at all to rotate the pulley if it were frictionless (maybe inertia would play a role, but let's ignore that)...

Here is the DE: Δu(r,θ)=0, 1 ≤ r ≤ 2, 0 ≤ θ ≤ pi and here are the Boundary Conditions: u(1,θ)=sin(θ), u(2,θ)=0, u(r,0)=0, u(r,pi)=0 Based on the Boundary Conditions I believe this is half of an annulus. Using the 2D Laplace equation for polar coordinates, find the solution u(r,θ). I've...