preface
Although SSDs have been very popular, there is still market space for large-capacity mechanical hard disks for storing large-capacity video files, etc., and the corresponding 3.5-inch large-capacity external hard disks have also been introduced. Mechanical hard disk for power supply requirements are quite high, the use of external power, need to have enough power to ensure the stable operation of the hard disk.
The charging head network got an external power supply for the Seagate Backup Plus Hub mobile hard disk, which is produced by Eurocomm, which supports wide voltage input and 12V3A output to meet the power supply needs of large-capacity mechanical hard disks. The following is a detailed disassembly of this power supply, let's take a look at the workmanship materials of this power supply.
The Seagate Portable Hard Drive 36W adapter comes out of the box
This adapter features a classic straight-panel design with a DC rounded output cable and a frosted corner of the housing.
The pin-independent modular design is secured by a snap button with a tripped press plate on one side that can be separated when pressed.
The independent module design of the plug can be replaced, solving the embarrassing situation that the user cannot use the plug in different areas of the user's business trip, just replace the plug without buying a new power supply, saving money and worry.
There is also a charger nameplate on one side of the pin
Model: ADS-40RJ-12
Input: 100-240V~50/60Hz 1A
Output: 12V3A
The charger has passed CCC, CE, UL, KC, VCCI certification.
The manufacturer printed on the side is Shenzhen Oulutong Electronics Co., Ltd., and the charger is also PSE certified.
The other side is also printed with EAC, NOM, NYCE certification marks, etc.
The measured length of the charger body is 84.92mm.
The width is 53.04mm.
The thickness is 33.68mm.
The measured cable is about 1.5 meters long and the plug is 5525 specifications.
Intuitive feeling of the charger in your hand.
Total weight business 185g.
Seagate Mobile HDD 36W Adapter Disassembled
After having a basic understanding of this adapter, the following charging head network will disassemble it in detail, let's see how the material work of the product is.
Unpack the power supply along the upper and lower cover seams of the power supply, glue the input and output lines, and fix the PCB inside the housing.
The power supply is a traditional design, the components are sparsely arranged, and the switch tube and synchronous rectifier tube are equipped with heat sinks, which effectively reduces the temperature rise of long-term operation.
The wire is soldered between the input pins and the PCB, and there is an insulated isolation board between the pins and the PCB.
The power input line is rubberized and reinforced.
The output line is also glued and reinforced.
At a glance on the front of the circuit board, the transformer is insulated with yellow tape, and components such as capacitors are glued and fixed.
The primary demarcation on the back of the board is obvious, and a black line identifies the primary and secondary areas.
The length of the board was measured using a vernier caliper of 76.2mm.
The width is 47.1mm.
The thickness is 23.4mm.
The charger is a flyback topology with a fixed voltage output to meet the power supply of low-power equipment. Below we start from the input to understand the material information of the power supply.
Input delay fuse with a specification of 3.15A 250V.
The input X capacitance is 0.33μF.
The common mode inductor is magnetically surrounded and has an insulated base at the bottom.
The rectifier bridge at the input terminal is from DiYi Electronics, the model is KBP306G, the withstand voltage is 600V, and the rated current is 3A.
One high voltage porcelain capacitor, 1000pF, 1KV withstand voltage, in parallel with the primary electrolytic capacitor.
The high voltage filter capacitor comes from the Acon intermediate, is 400V 82μF, and the glue is fixed to the board.
The switching power supply main control chip is from Onbao, model OB2362, which is a highly integrated current mode PWM controller. The chip has integrated high-voltage start-up, low standby power consumption and wide output voltage range, good compatibility, suitable for cost-effective flyback power supply design.
The switch tubes are from Universal Semiconductor, MFIRF7N65, NMOS, withstand voltage 650V, conductivity 1.5Ω, and are available in TO220F insulated packages.
Close-up of the primary current sense resistor.
Small capacitor that powers the main control chip, from Sanying, NXA series, 50V 4.7μF.
M7 diode for flyback RCD absorption circuitry.
Close-up of the transformer with EF-25 core.
CT 817B optocoupler for output voltage feedback.
Blue Y capacitor close-up.
The secondary synchronous rectifier controller adopts MPS chip-source semiconductor MP6902DS, which is a synchronous rectifier controller that supports DCM and QR flyback, supports 12V standard synchronous rectifier tube and 5V logic voltage drive rectifier, supports 8-24V output voltage range, supports up to 400KHz operating frequency, and supports high-side and low-side synchronous rectification.
Synchronous rectifier tubes from new power, NCE0157A2, NMOS tubes, withstand voltage 100V, conductivity 14mΩ, available in TO220 package.
The two output filter electrolytic capacitors are from Acon neutrals and are low internal resistance models, each with a specification of 1000μF 16V.
The output common-mode inductor is used for filtering.
All disassembled, let's take a family portrait.
Charging head net disassembly summary
With the progress of the information society now, the amount of data that individuals want to store is getting larger and larger, and the choice of 3.5-inch mobile hard disk as fixed storage has a faster speed and greater capacity than a 2.5-inch mobile hard disk, so it is also accepted by many people. For hard drives that hold precious data, a stable power supply comes first.
Charging head network through disassembly to understand, Oulutong this power supply using Diyi technology rectifier bridge input filtering, switching power supply using Apo OB2362 + MPS MP6902 synchronous rectification scheme, primary switch tube from Universal Semiconductor, secondary synchronous rectifier tube from new power, capacitors all using Acon zhongyuan. As the Original Seagate factory selection of Continental Power Supply, although its appearance is not impressive, the internal design is still quite reliable.