Recent content by Leafhill

If any of you happen to have a spare 100% efficient motor lying around, let me know. I'm willing to pay for it :-) Anyway, I think I've gotten a bit closer to my original question conserning the relationship between Watts and Newtons. As many of you have allready explained quite detailed...

Hi, Berkeman! Thanks for the link. I'll check it out. So it seams that I need to find ways of eliminating speed and motion from the equations. As I'm sure you are aware of by now I don't care much for motion. I simply don't need it, but I do need the power and I do need the force (May the...

So is there any equations anywhere taking into account thermal energy being produced to maintain a helicopter in its hover? If I know the weight of the helicopter and the downward force (gravity = 9.81 m/s^2) I should be able to calculate the amount of watts being consumed. Am I right?

Hi, Jeff! Thanks! So Power = force * speed. OK, but my speed is zero m/s. Nothing is moving, but the spring is kept tight and my motor is consuming watts. Clearly there is power being consumed, but it doesn't look like these equations cover the cases I'm explaining. The power that is usually...

Hi, Saunderson! I'm sure your equations are correct, but I'm more practical than theoretical, and have difficulties accepting the results. My view is something like this: If you are a waiter and holding a tray of food in one hand, you are continuously working against gravity by applying a...

Hi, berkeman! The motors I use is normally specified at 85% efficiency under normal load. This is not at locked shaft where it probably will be a bit lower. It will also heat up due to the higher current being pulled, but a proper motor controller can continuously monitor this and reduce this...

Hi, stewartcs! The motor output force does NOT depend on the motor specification. I can with high accuracy (using dedicated electric equipment) control how many amps and volts (or if you will watts) should be applied to the motor. The more I supply the motor, the more the motor will respond...

Correct! The object is not moving, but the force of one Newton is there and it is consuming power. How much? I'm sure you allready know this, but to be sure we and anyone else reading this are on the same page I'll write it anyway. Inside the motor is a copper coil facing a magnet. These are...

No, the motor is not moving, but it is connected to a power supply. This applies a force on its output shaft trying to pull on the object even if it is not able to actually move it.

Wow, fast reply! thanks! Still have some issues to understand, though. My brick is not actually moving so distance is kind of irrelevant. Its got the 1m/s^2 acceleration force (1 N), but what if a spring is holding it in place? It's not moving anywhere, but the force is still there and my motor...

Hi! So I thought I knew the laws of physics and electronics, but I've recently stumbled on to a puzzling bit of "Math vs Pratical application". I'm messing up the forces and equations in my strained little head, so I'll let you guys have a go. I'll go into practical applications of this...

Wait, I just realized something. Isn't the Coefficient of Discharge actually just a value for the efficiancy, or if you will the loss in pressure through the venturi? This value tends to be really high (such as 0.95), so at the inlet I should be getting about 95% of the velocity of the water...

Hehe, yeah the scale hasn't really been defined yet. I'm doing this with a friend and will keep it at a relaxing spare time project for now. The fish pond version as a start and scale it up later. I've noticed as you said, that the pressure rises with the square of the speed...

Cool! No, I haven't seen that particular one before.

Well, I made a tiny venturi design (using Pro Engineer) for my kitchen tap. 23mm inlet and outlet and 3mm throat. I printed it using the Zcorp 3D-Printer (amazing machine) and mounted the finished bonafied venturi to my tap. I measured the total pressure drop between inlet and throat to 2.8...