Preface
Delta's PJT-100WBB series is an open power module, which supports 90-264Vac input voltage, with 12V, 15V, 18V and 24V output voltages, and a nominal output power of 100W. The module has a nominal weight of 150 grams and dimensions of an industry standard of 2 inches x 4 inches.
The output voltage of this module obtained by the charging head network is 18V, the output power is 100W under forced air cooling, and the output current is 5.55A, and the output power is 80W under natural convection, and the output current is 4.44A. The power module is connected by terminal blocks for easy installation and maintenance.
The power module has passed CB, CE&UKCA, REACH, TSCA, TUV and UL safety standards, and supports operating environments from -10°C to 70°C.
Unboxing of Delta's PJT-100WBB open power module
Delta's PJT-100WBB open power module achieves 100W power and size control very well, and the two sides of the motherboard are equipped with heat dissipation plates for the main heating devices of the rectifier bridge and primary switch MOS tube.
One side of the heat sink is pasted with a module information sticker, model PJT-18V100WBB, support 100-240V~50/60Hz 2.5A input, and 18V5.55A output, passed the CE certification.
The soldering of the large and small devices on the back of the motherboard is clean and neat, and the craftsmanship is of high standard.
The length of the PCBA module is about 101.8mm measured by vernier calipers.
The width of the PCBA module is about 51mm.
The thickness of the PCBA module is about 30.1mm.
The weight of the power module is about 138g.
Analysis of Delta's PJT-100WBB open power module
After reading the appearance of Delta's power module, let's take a look at the design and materials of this power module.
The front of the PCBA module is at a glance, where the right side is the input terminal, soldered power input socket, fuse, NTC thermistor, safety X2 capacitor, common mode inductor and rectifier bridge, Y capacitor jacket heat shrinkable tube insulation. On the left side of the gray safety X2 capacitor is the high-voltage filter capacitor, transformer, and on the left side is the filter capacitor, filter inductor and output terminal.
The rectifier bridge and primary switch tube are fixed on the upper heat sink, and the output rectifier tube is fixed on the small heat sink in the lower left corner, so as to increase the heat dissipation area, and use forced air cooling or natural convection to dissipate heat.
There is a primary main control chip on the back of the PCBA module, and the demarcation between the primary stages is clear.
Through the observation of the PCBA module, it is found that Delta's power module uses a flyback switching power supply with a fixed voltage output. The output voltage is fed back by an optocoupler. Let's start with the input to understand the information of each device.
PCBA module input at a glance, soldered fuse, NTC thermistor, safety X2 capacitor, common mode inductor and safety Y capacitor, right side heat sink fixed rectifier bridge.
The fuse jacket is insulated with heat shrinkable tubing, and the specification is 5A250V.
Green NTC thermistor silkscreen SCK 054 844 for inrush current suppression at power-up.
The safety X2 capacitor is from Europ and has a specification of 0.33μF.
The common mode inductor is made of magnetic surrounding, and the jacket is insulated by heat shrinkable tubing.
Blue Y capacitor jacket heat shrink tubing insulation.
The rectifier bridge and switch tube are fixed on the heat sink on the side of the PCBA module, and the power supply information label is pasted, and the position of the corresponding secondary components is insulated with tape.
The rectifier bridge is fixed to the heat sink using screws and coated with silicone grease to conduct heat.
The side of the PCBA module is equipped with a rectifier tube heat sink and a high-voltage filter capacitor.
The high-voltage filter capacitors are from Chemi-Con and are miniaturized and long-life electrolytic capacitors of the KXG series, with a specification of 400 V and 180 μF.
The power supply main control chip model is DAP018B, from onsemi, customized for Delta, with a switching frequency of 65kHz and extremely low standby power consumption.
The filter capacitor that supplies power to the main control chip is insulated with heat shrinkable tubes.
NTC thermistors are used to detect the temperature of the power supply and provide overtemperature protection.
The primary switch is from Infineon, model SPA11N65C3, NMOS, withstand voltage 650 V, conduction resistance 380 mΩ, and is available in a PG-TO220FP package.
A 200mΩ resistor is used to sense the primary current.
The transformer core is insulated with tape on the secondary side.
Blue Y capacitor jacket heat shrink tubing insulation.
Everlight EL816 optocoupler is used for output voltage feedback.
The Schottky diodes are from STMicroelectronics, model number STPS30120CT, 120V30A, in a TO220AB package that is screwed to a heat sink.
The output side is welded with a high-voltage filter capacitor, a potentiometer and an output socket.
The two output filter capacitors are from ruby.
The capacitance specification is 25V1000μF, which is the ZLH long-life series.
The filter inductor is magnetically wrapped.
The output filter capacitor specification is 25V560μF.
The screen K511 chip is a single voltage comparator for secondary overtemperature protection.
Close-up of a thermistor used to detect secondary temperatures.
The chip of silkscreen T4F3 is a voltage reference from Texas Instruments, model TL432, which cooperates with optocoupler for output voltage regulation.
The blue potentiometer is used to fine-tune the output voltage.
Close-up of the DC output terminal.
Summary of the charging head network
Delta's PJT-100WBB power module has an open design and is suitable for use in situations where it cannot be touched by people, such as in a chassis. The power module supports a wide voltage input of 90-264Vac, the output voltage is 18V, and the nominal output power can reach 100W under forced air cooling, and the output power derating is 80W under natural convection.
Through analysis, the charging head network learned that Delta's power module adopts a flyback switching power supply architecture, the primary controller is a customized DAP018B model, the primary switch is Infineon SPA11N65C3, and the rectifier Schottky diode is STPS30120CT STMicroelectronics.
The power module adopts Japanese long-life electrolytic capacitors, and the components are reinforced with glue. Components such as rectifier bridges and switches dissipate heat through heat sinks on both sides of the module to reduce the temperature rise. The primary stage of the power module is equipped with a thermistor for overheating protection to ensure safe and reliable operation.