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How does the output voltage of the VFD change if the DC bus voltage level is fixed?
Wiki User
∙ 13y ago
The VFD outputs pulses at the DC bus voltage. Each pulse is from the DC bus and the voltage does not change. It is the average voltage that changes because the VFD changes the on and off times of these pulses. For a lower average ac voltage to the motor, the ON time is small and the OFF time is large. The VFD actually pulses about 4000 times per second, so the motor does not really know these are just lots of quick DC bus voltage pulses. To simulate an ac waveform, the VFD uses pulse-width modulation which means the pulse ON time at the peak of the simulated sinewave is longer, or fatter, than the pulses where the simulated sinewave is closer to 0 crossing.
Wiki User
∙ 13y ago
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How do you convert dc to ac current?
The AC current is fed into a rectifier, which is a set of four diodes that force the current at the output to be one direction. A capacitor across the rectifier output is then used to smooth out the voltage to a level higher than the desired DC output (eliminating, for example, the zero-voltage portions of the original AC sine-wave) A voltage regulator then regulates the voltage to a constant level.
Can you improve voltage level in the range of millivolt into a 15volt?
A voltage amplifier (high input and output impedances) with a gain of 83.5 dB will amplify a signal of 1 millivolt to an output of 15 volts.
What is the voltage level on the output modules?
It could be anything from 1.5 v to a megavolt, depending on the nature of the power modules.
Why transformers are not excited with dc?
by using step-up transformer we can change the voltage in higher level
Does alternating voltage changes its value or direction?
AC voltage with no DC offset will change both it's voltage level (constant change, hence AC) and polarity (ie direction) every 1/2 cycle when it crosses zero.
What are a business firm's fixed and variable costs of production?
Fixed costs are costs that do not vary with the level of output, such as rent and insurance premiums. Variable costs are costs that change with the level of output, such as wages and raw materials.
What happens to the value of average fixed cost as the level of output increases?
The average fixed cost is equal to fixed cost divided by level of output, if the output increases; the average fixed cost is less.
What is the Difference between linear IC and digital IC?
Both linear ICs and nonlinear ICs has an output voltage which is dependent on the input voltage. However, the difference is that linear ICs produce an output voltage which increases or decreases at a "fixed rate" relative to the input voltage. Nonlinear ICs do not do this. A voltage regulator may be considered nonlinear because as you increase the input voltage the output will climb at the same rate (just like linear ICs), however, once the input voltage reaches a particular level point, the output no longer increases as you increase the input. This is at the point where regulation begins. The nonlinear IC no longer changes its output at a fixed rate relative to the input.
Is it the value of input voltage equal the value of output voltage?
No. There are several factors that may affect the output voltage. For instance: Resistors, Transformer, Voltage regulators and others that can control the output voltage to a certain level.
How does a series regulator maintain the output voltage at a constant level?
A series regulator maintains the output voltage at a constant level by constantly changing the effective resistance of the pass device, usually the output transistor.
What is a v out?
"Vout" typically refers to the output voltage of a circuit or device. It is the voltage level that is generated or present at the output terminal or node of the circuit. Voltage output is a common measurement parameter in electronics and electrical engineering.
Why does the level of fixed cost not have any influence on the profit maximising level of output?
i really don't know
Is it true that fix cost remains same when output increases?
The real answer is it depends, ultimately all costs are variable even those costs that would initially appear fixed. Take for example business rates, these are set for the year and will remain the same regardless of the change in volume of the output, however should the output need to rise above the capacity of the existing business premises additional premises or even new premises would need to be acquired and with it a new level of fixed cost. This is sometimes described as step fixed cost, i.e. the cost remains at the same level until a step change is required and then the costs are again fixed at this new level until another step change is required
How do you convert dc to ac current?
The AC current is fed into a rectifier, which is a set of four diodes that force the current at the output to be one direction. A capacitor across the rectifier output is then used to smooth out the voltage to a level higher than the desired DC output (eliminating, for example, the zero-voltage portions of the original AC sine-wave) A voltage regulator then regulates the voltage to a constant level.
Can you improve voltage level in the range of millivolt into a 15volt?
A voltage amplifier (high input and output impedances) with a gain of 83.5 dB will amplify a signal of 1 millivolt to an output of 15 volts.
How do you get more vapor e-cig?
The "Juice" or "E-Liquid" content of "propyleneglycol" or "vegetableglycerine" determines the amount of "smoke" (vapor).Entry level devices have a fixed voltage / wattage rating, and most have fixed resistances in the heating head. Only changing the type of liquid will change the level of vapor in these units.Higher end units are able to change the voltage / wattage as well as the resistance of the heating coil to get more 'smoke' from the liquid.
Is Advertising fixed costs?
If advertising expense is fixed and has no concern with level of sales then it Is fixed but if it is changed with the change in level of sales then It is variable cost.
