Main products: power adapter, medical power, LED power, charger and so on.
Shenzhen Lianyunda Electronics Co., Ltd. is committed to doing a good job in power supply products, and sincerely welcomes customers to contact us by phone or email.
As laptops become more powerful and consume more power, the current notebook power adapters have not met the requirements of next-generation notebooks, and it is necessary to develop power adapters that meet the requirements of next-generation notebooks.
Analysis of the structure of the power adapter
Next, let's take a look at the internal structure of the power adapter. The main components of the circuit have been marked with a circle, the part name and function are as follows:
1. A varistor whose function is that when the external voltage is too high, the resistance of the varistor quickly becomes very small, and the fuse connected in series with the varistor is blown, thereby protecting other circuits from being burned out.
2. The fuse has a specification of 2.5A/250V. When the current in the circuit is too large, the fuse will blow to protect other components.
3. Inductor coil (also known as choke), the main function is to reduce electromagnetic interference.
4. Rectifier bridge, the specification is D3SB, the function is to convert 220V AC into DC power.
5. Filter capacitor, the specification is 180μF/400V, the function is to filter out the AC ripple in DC, which makes the circuit work more reliable.
6. Op amp IC (integrated circuit), an important part of protection circuit and voltage regulation.
7. The temperature probe is used to detect the internal temperature of the power adapter. When the temperature is higher than a certain set value (the power adapter of different brands has a slightly different temperature threshold), the protection circuit will cut off the voltage output of the adapter. To protect the adapter from damage.
8. The high-power switch tube is one of the core components in the switching power supply. The switching power supply can work “open and close”, and the switch tube is indispensable.
9. Switching transformer, one of the core components in the switching power supply.
10. Secondary rectifier, the function is to change the low-voltage alternating current into low-voltage direct current. In IBM's power adapters, the rectifiers are often operated in parallel by two high powers to achieve a large current output.
11. Secondary filter capacitors, 820μF/25V, have two functions, which filter the ripple in low-voltage DC. In addition to the above components, there are adjustable potentiometers and other RC components on the board.
Disassembly of the power adapter
The upper and lower covers of the notebook power adapter are injection-molded or glued with super glue. They do not need any screws, so they can only be cracked by violence. However, as long as the method is correct, the disassembled power adapter can be completely restored, and no traces of disassembly can be seen without careful observation.
Disassembly tools: electrician knife, hammer, screwdriver, electric iron, utility knife, etc.
Place the lateral side of the power adapter on the white paper, cut it with the electric knife blade along the gap between the upper and lower covers of the power adapter, and then tap the back of the electric knife with a hammer to cut the electric knife between the upper and lower covers of the adapter. At different positions of the gap between the upper and lower covers of the adapter, use the tip of the electrician knife to move along the slit. When a certain part of the upper and lower covers is first cracked, the tip of the blade is deepened, and then the upper and lower covers of the adapter are slowly separated.
In order to open the power adapter of the outer casing, you can see that the outer layer of the adapter circuit has a copper shielding layer, use a utility knife to cut the tape on the shielding layer, and then solder the two welding wires connected to the inner circuit board by the electric soldering iron. Click to remove the shield.
There is a thick layer of hard plastic film between the shielding layer and the circuit board. After cutting it with a utility knife, you can see the true face of the circuit board.