In electronics, a power supply is a device that converts AC voltage continuous, feeding the various circuits electronic device you connect to (computer, television, printer, router, etc.).
supply network in one or several strains, virtually
Rating
power supplies for electronic devices, can be classified mainly as linear power supplies and switches. The linear with a relatively simple design, which can become more complex the higher the current to be supplied, however their voltage regulation is very efficient . A switching power supply, the same power as a linear will be smaller and usually more efficient but is more complex and therefore more susceptible to breakdowns.
Linear Power
linear sources, follow the pattern: transformer, rectifier, filter, and output regulation. First, the transformer adapts the voltage levels and provides galvanic isolation. The circuit that converts alternating current continually called rectifier, then usually have a circuit that reduces the ripple as a filter capacitor . Regulation, or stabilization voltage to a value set, is achieved with a component called voltage regulator. The output can be simply a capacitor.
A switching power supply is an electronic device that converts electrical energy by switching transistors. While a voltage regulator uses transistors biased in the active region of amplification, the sources
TES switched actively use the same switch at high frequencies (20-100 KHz typically) from cut (open) and saturation (Closed). The resulting square waveform is applied to core transformers ferrite (iron cores are not suitable for these high frequencies) for one or more output voltages of alternating current (AC) which are then ground (with gave two quick
) and filtered (inductors and capacitors) for output voltages of direct current (DC). The advantages of this method include smaller size and kernel weight, increased efficiency, thus less heat. The disadvantages comparing with linear sources is that they are more complex and generate high-frequency electrical noise that must be carefully minimized to avoid causing interference to nearby equipment to these sources.
Switching Power Supply
sources are switched scheme: rectifier, switch, transformer, rectifier and other output. The control is obtained with the switch, typically a PWM circuit Pulse Width Modulation), changing the duty cycle. Here the functions of the transformer are the same as for line sources, but their position is different. The second rectifier converts alternating pulse signal coming from the transformer into a continuous value. The output can also be a filter capacitor or an LC type . (
The advantages of open source is a linear better regulation, better speed and EMC characteristics. On the other hand, the switched gain a better performance, lower cost and size.
Specifications
A fundamental specification of power is the yield, defined as total output power between active power input. As mentioned earlier, switching power supplies are better in this aspect.
The power factor is the active power between the input apparent power. Is a measure of the quality of the stream.
Apart from reducing the ripple as possible, the source must maintain the output voltage to the voltage applied regardless of fluctuations in the line, line regulation or charge required by the circuit load regulation.
Special Power
Among the alternative power sources, we can find where the power is delivered to the load is being controlled by transistors, which are controlled in phase to deliver the power required to load.
Other alternative sources of power, scheduled and special are those where the frequency is varied, keeping the voltage amplitude achieving a variable font effect in cases such as motors and transformers in voltage ...
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