PCB Tech - PCB functional characteristics and related knowledge

The performance characteristics of the circuit board

1. Internal circuit board structure

The circuit board of the air conditioner is usually referred to as PCB in the technical information. Generally, the circuit board of the air conditioner is in the indoor unit, but due to the difference in size and function of the air conditioner, some air conditioners also have circuit boards in the external unit, and some air conditioners have multiple circuit boards, circuit boards and circuit boards in the internal unit. They are usually connected by connectors.

(1) Single board circuit air conditioner

The single-board circuit of the air conditioner means that the circuit of the air conditioner is mainly composed of a circuit board, which is common in hanging up. Generally, the circuits in the circuit board of single-board circuit air conditioners mainly include: CPU control circuit, power circuit, signal drive circuit, wind direction control circuit, internal fan control circuit, etc.

In addition to this main circuit board, single-board circuit air conditioners usually have a small circuit board indoors. The main circuits in the small circuit board are the indicator light circuit and the remote control receiving circuit. Several wires are connected between the main circuit and the small circuit board through connectors.

(2) Double board circuit air conditioner

The dual-board circuit of the air conditioner means that the main components of the air conditioner circuit are on two circuit boards, one is mainly the control circuit, usually called a computer board; the other is mainly the power supply circuit and the signal drive circuit, usually called the power drive board . The two circuit boards are connected by a multi-stranded wire connector, and the function of the connecting wire is mainly a DC power supply and a control signal.

(3) Remote control and indication PCB

Common air conditioners have remote control and indication functions. Generally, the remote control receiving and indication function circuit is made into a separate small circuit board, which is connected with the main control circuit board using several wires. The circuit board mainly has a remote control receiver and several light-emitting diodes., Common in on-hook.

The function of the remote control receiver is to receive the signal sent by the remote control, and send it to the CPU after conversion.

Light-emitting diodes generally have two red and green or three red, green and yellow, which are mainly used to indicate power supply status, compressor working status and other related working status.

(4) Air conditioner PCB with display screen

Air conditioner circuit boards with display screens are mostly found in cabinets, and a few on-hooks also have display screens. Generally, the internal machine is composed of two electric boards, one is a control board composed of a control circuit, a power circuit, a signal drive circuit, etc., and the other is an air conditioner circuit board with a display screen.

The air conditioner circuit board with a display screen, the internal circuit mainly includes a display circuit, a remote control receiving circuit, a key matrix circuit, etc., which are connected to the main control circuit board through a number of wires. Air conditioner circuit board with display screen, and some air conditioner control circuits also make the circuit on the display board.

Common display screens generally include LED digital tube display, LCD liquid crystal display, VFD fluorescent display and so on.

2. External circuit board structure

In addition to the internal circuit board of the air conditioner, the external unit of the air conditioner will also be equipped with an external circuit board according to the structure of the control circuit.

Two routing methods for circuit boards

In today's society, the coverage rate of electronic products is getting bigger and bigger. Unlike in our 70s and 80s, even the TV is very ugly to see, and it is simply incomparable to today. There is a direct connection between electronic products and circuit boards. Without circuit boards, there are no electronic products. But how are circuit boards produced? The following is a circuit board maintenance expert on the wiring method of circuit boards.

The first method: manual wiring method

The first step is to ensure the level and size of the circuit board.

The second step is to place the package of the components and arrange the package of the components.

The third step, according to the schematic diagram of the circuit board, you can directly use the Place/interactiveRouting menu to manually route.

The fourth step is to modify the circuit board, save it or print the file.

The manual wiring method is more difficult to operate and the efficiency is relatively low, but this wiring method is generally better than the automatic wiring method.

The second method: automatic wiring method

The first step is to use the schematic editor to design a schematic diagram, perform an electrical check (ERC) and generate a netlist of the schematic diagram (Netlist).

The second step is to enter the PCB environment and use the circuit wizard to determine the number of layers and size of the circuit board and other circuit board parameters.

The third step is to use the Design/Netlist menu to load the netlist. Note: At this time, it is easier to make common errors that the package in the netlist and the component package in the package library do not match.

The fourth step is to arrange the components and distribute the components on the circuit board reasonably. Arrange components automatically or manually. Note that this action often requires multiple layouts to achieve the effect.

The fifth step is to set automatic wiring rules and automatic wiring.

The sixth step is to complete retouching and other work. Save the circuit board file or print out.

The automatic wiring method is easy to operate and has a relatively high efficiency. The method made by this method is usually worse than the manual method.

How to design a circuit board, there are two different wiring methods, each has its own advantages, depending on which occasion it is used, you can use different wiring methods according to different situations.