What Is a Power Supply Board?
A power supply board is responsible for supplying the voltage and current that meets the specifications to the circuits that make up the equipment.
Generally, the power supply circuit is designed to take 100 V AC commercial power as input and output the DC voltage required by the internal circuits. The DC voltage required by the internal circuits can be aggregated to between 3.3 V and 48 V, depending on the equipment. Furthermore, the required current values can also be aggregated.
The value of utilising a power supply board with a power supply circuit made for general purpose use as a finished component, rather than optimising and designing it for individual devices in-house, is significant.
Costs can be reduced by narrowing down the specifications to a few types of power supply board and producing them in large quantities. The reason for this is that engineers specialising in power supply circuit design can design high-performance designs.
Uses of Power Supply Boards
Power supply boards are used in a wide range of equipment, including industrial equipment, information processing equipment such as computers and servers, home appliances such as televisions and refrigerators, and audio-visual equipment such as recorders and audio components.
The installation space allowed for power supply circuits is becoming increasingly restricted due to the increasing sophistication and performance of various devices and the miniaturisation of equipment, resulting in the need for miniaturisation, high performance and high efficiency.
The need for dedicated power supply boards is increasing for these reasons, in addition to the potential cost savings compared to in-house design.
Principle of Power Supply Boards
Power supply boards include AC/DC power supply boards, which convert AC voltage to DC voltage, and DC/DC power supply boards, which boost or step down DC voltage.
1. AC/DC Power Supply Boards
Generally takes 100 V AC commercial power as input and outputs the specific DC voltage required by the equipment’s internal circuitry.
2, DC/DC Power Supply Board
After being converted to DC voltage in the equipment, the output is further boosted or stepped down to the specified voltage required by the internal circuits.
In addition to simply converting AC to DC or converting DC voltage, there are many power supply boards with various built-in protective functions, such as overcurrent protection circuits and overvoltage protection circuits to deter excessive current from flowing into the internal circuits, and overcurrent protection circuits to deter heating due to the amount of current flowing into the circuit. Many power supply boards are available.
In addition, power supply circuits can sometimes cause heat generation and ignition due to incorrect use of the equipment. As standards are strictly defined by various safety standards, power supply boards are generally compliant with various safety standards.
Other Information on Power Supply Boards
1. Benefits of Power Supply Boards
One advantage of power supply boards is that they reduce EMI (Electro Magnetic Interference) noise. The DC-DC converter IC, which is a major noise source, and the coils and capacitors are wired short, and the optimised structure reduces noise.
Noise emitted by DC-DC converters is amplified by the wiring acting like an antenna, so shortening the wiring is an effective noise suppression measure.
2. Types of Dc-Dc Converter Operation
There are two types of operation among DC-DC converters.
Linear Regulators.
This is a method of obtaining an output voltage by dividing the input voltage between the loads. The voltage divider ratio can be changed by using a transistor or similar between the loads and treating it as a variable resistor.
This method has the disadvantage of low energy conversion efficiency, as the power consumed by the voltage dividing resistor is lost. On the other hand, the advantages include low electromagnetic noise.
Switching Regulator
This is a method whereby a pulse wave is created from the input voltage by switching elements on and off, and smoothed at the output. The voltage can be controlled by changing the on/off ratio.
It has high energy conversion efficiency, but has the disadvantage of high noise generated during switching.