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Power Ramp
In telecommunications, power ramp is the way in which the signal increases ("power-on ramp") or falls off ("power-down ramp"), which may result in spectral splatter. See also * Soft start * Power gating * Voltage scaling Dynamic voltage scaling is a power management technique in computer architecture, where the voltage used in a component is increased or decreased, depending upon circumstances. Dynamic voltage scaling to increase voltage is known as overvolting; d ... Telecommunications engineering {{telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Splatter
{{unreferenced, date=February 2008 In radio electronics or acoustics, spectral splatter (also called ''switch noise'') refers to spurious emissions that result from an abrupt change in the transmitted signal, usually when transmission is started or stopped. For example, a device transmitting a sine wave produces a single peak in the frequency spectrum; however, if the device abruptly starts or stops transmitting this sine wave, it will emit noise at frequencies other than the frequency of the sine wave. This noise is known as spectral splatter. When the signal is represented in the time domain, an abrupt change may not be visually apparent; in the frequency domain, however, the abrupt change causes the appearance of spikes at various frequencies. A sharper change in the time domain usually results in more spikes or stronger spikes in the frequency domain. Spectral splatter can thus be reduced by making the change more smooth. Controlling the power ramp shape (i.e. the way in whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Start
A motor soft starter is a device used with AC electrical motors to temporarily reduce the load and torque in the powertrain and electric current surge of the motor during start-up. This reduces the mechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network, extending the lifespan of the system. It can consist of mechanical or electrical devices, or a combination of both. Mechanical soft starters include clutches and several types of couplings using a fluid, magnetic forces, or steel shot to transmit torque, similar to other forms of torque limiter. Electrical soft starters can be any control system that reduces the torque by temporarily reducing the voltage or current input, or a device that temporarily alters how the motor is connected in the electric circuit. Operating principles Whenever the armature of an electric motor is moving, both the ''motor action'' and ''generator action'' are occ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Gating
Power gating is a technique used in integrated circuit design to reduce power consumption, by shutting off the current to blocks of the circuit that are not in use. In addition to reducing stand-by or leakage power, power gating has the benefit of enabling Iddq testing. Overview Power gating affects design architecture more than clock gating. It increases time delays, as power gated modes have to be safely entered and exited. Architectural trade-offs exist between designing for the amount of leakage power saving in low power modes and the energy dissipation to enter and exit the low power modes. Shutting down the blocks can be accomplished either by software or hardware. Driver software can schedule the power down operations. Hardware timers can be utilized. A dedicated power management controller is another option. An externally switched power supply is a very basic form of power gating to achieve long term leakage power reduction. To shut off the block for small intervals of ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Scaling
Dynamic voltage scaling is a power management technique in computer architecture, where the voltage used in a component is increased or decreased, depending upon circumstances. Dynamic voltage scaling to increase voltage is known as overvolting; dynamic voltage scaling to decrease voltage is known as undervolting. Undervolting is done in order to conserve power, particularly in laptops and other mobile devices, where energy comes from a battery and thus is limited, or in rare cases, to increase reliability. Overvolting is done in order to support higher frequencies for performance. The term "overvolting" is also used to refer to increasing static operating voltage of computer components to allow operation at higher speed (overclocking). Background MOSFET-based digital circuits operate using voltages at circuit nodes to represent logical state. The voltage at these nodes switches between a high voltage and a low voltage during normal operation—when the inputs to a logic gat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
