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| Need somebody to talk to about AC concept |
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| hamster_nz:
--- Quote from: tester43 on June 28, 2018, 09:09:31 pm ---But in AC you are sitting in the boat. Water is constantly kicking you up and down.There is no possibility to be aware is you are at the time at height 2, 6, -2 or other. That was my confusion. At least I know I can detect zero EMF (zero volts). So to overcome this situation I used Bridge rectifier to have my solid reference point - to get of the boat, stand of the rock and measure how waves are coming and change its height with time. --- End quote --- If you make a measurement in an AC circuit you might be the equivalent of sitting in a kayak, moving up and down on the waves. One end will go up slightly with respect to the other as the waves pass. However, think of GND as being a very large barge or super-tanker. It is so large that waves are unable to make it move significantly. It is still 'floating', but can be used as a stable reference for measuring the height of waves while still being out in open ocean. ... musings... To me it seams DC/AC thing is a matter of scale. Everything AC acts like DC at a very small timescale or when operating at low frequencies, and everything DC starts acting like AC at very large time scales or when operating at high frequencies. The tricky bit is the bit where things are "sort of DC, and sort of AC", and doing a simple DC or AC analysis doesn't tell the whole story. Typically that is also where all the interesting, useful things happen (like filters, and power supply ripple/noise, and PWM modulation, and high speed digital, and transmission lines, and ...) |
| NorthGuy:
Imagine, you have an output of the transformer, which, you know, produces AC. You decide one of the wires is your ground. You can connected it to earth. Then you draw the waveform of voltage on the other wire. This will be a sine wave centered on zero. Now add a rectifier. It'll have two terminals - "+" and "-" with DC between them. Now, looking at the diodes in the rectifier and at the waveform on the AC wire, draw the waveforms on the "+" and "-" terminals relative to your ground. This may take you a while to do. Look at the resulting "+" and "-" waveforms. What do you think? |
| BravoV:
--- Quote from: C on June 28, 2018, 09:36:15 pm ---If you want to compare electricity to Water then Voltage = pressure of the water. Current = the flow rate of water Resistance = size of pipe. Wire = pipe Capacitor = water tower where you store a mass of water Inductance = mass of water flow resisting change in flow rate. Inductance = water wheel resisting change in water flow rate, or changing (speed up or slow down) the water flow if the wheel has been rotated that has it's own rotating inertia --- End quote --- There, a bit improvements on inductance analogy ... :P |
| C:
--- Quote from: BravoV on June 28, 2018, 11:40:55 pm --- --- Quote from: C on June 28, 2018, 09:36:15 pm ---If you want to compare electricity to Water then Voltage = pressure of the water. Current = the flow rate of water Resistance = size of pipe. Wire = pipe Capacitor = water tower where you store a mass of water Inductance = mass of water flow resisting change in flow rate. Inductance = water wheel resisting change in water flow rate, or changing (speed up or slow down) the water flow if the wheel has been rotated that has it's own rotating inertia --- End quote --- There, a bit improvements on inductance analogy ... :P --- End quote --- Actually I think this change is bad. Your water wheel example of use of mass but does not match up to electrical inductance. Inductance is created by the magnetic field. More or less current changes the magnetic field. Using my deflations above with current = flow rate of water, A change of flow rate is a change in mass per unit of time. This mass of water is the equal of inductance. Where mass is resistant change in speed, inductance is resistant to current change. This fits in with the other deflations. A wire has some inductance, A coil of wire has more inductance. A pipe contains x amount of water(mass), A coil of pipe adds the centrifugal force to the mass of water causing an increase in resistance to change. |
| BravoV:
How about the wheel it self has a mass which is significantly greater than the mass of the flowing water (the parasitic inductance) ? |
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