source:Industry News Popular:adapter release time:2021-12-28 10:17:21 Article author:sznbone
The following are the main reasons for the low output voltage caused by the power adapter:
1. Switching power supply load short-circuit failure (especially DC/DC converter short-circuit or poor performance, etc.), at this time, first disconnect all loads of the switching power supply circuit, and check whether the switching power supply circuit is faulty or the load circuit is faulty. If the load circuit is disconnected and the voltage output is normal, it means that the load is too heavy; or it is still abnormal, it means that the switching power supply circuit is faulty.
2. The failure of the filter capacitor or rectifier diode at the output voltage can be judged by the replacement method.
3. The performance of the switching tube is degraded, causing the switching tube to fail to conduct normally, which increases the internal resistance of the power supply and reduces the load capacity.
4. Poor switching transformer not only causes the output voltage to drop, but also causes insufficient excitation of the switching tube and damages the switching tube.
5. The poor 300V filter capacitor results in poor load carrying capacity of the power supply, and the output voltage will drop as soon as the load is connected.
The output voltage is too high
Excessive output voltage generally comes from voltage stabilization sampling and voltage stabilization control circuits. In the closed control loop composed of DC output, sampling resistor, error sampling amplifier such as TL431, optocoupler, power control chip and other circuits, any one of the components will cause the output voltage to rise.
The fuse is normal, no output voltage
The fuse is normal and no output voltage indicates that the switching power supply is not working or has entered a protection state. The first step is to check the value of the startup voltage of the startup pin of the power control chip. If there is no startup voltage or the startup voltage is too low, check whether the external components of the startup pin and the startup resistor are leaking.
If the power control chip is normal, the fault can be quickly found through the above monitoring. If there is a startup voltage, measure whether there are high and low level jumps at the output terminal of the control chip at the moment of power-on. If there is no jump, it means that the control chip is damaged, the peripheral oscillation circuit components are damaged or the protection circuit is faulty, and the control chip is replaced. Chips, check the peripheral components, and check them one by one; if they are changing, most of them are bad or damaged switch tubes.
Insurance burned out or blown up
Mainly check the rectifier bridge, each diode, switch tube and the large filter capacitor on 300 volts and other parts. It may cause the insurance to burn and turn black, or it may be caused by a problem with the anti-interference circuit. It is especially worth noting that the fuse is burnt due to the breakdown of the switch tube, which usually burns out the power control chip and the current detection resistor. The thermistor is also easy to burn out along with the insurance
Read recommendations:
MKS-1203000EX Switching Power Supply
How to recognize the power adapter? The three easiest detection methods!
Precautions for matching plug power cords for electrical and mechanical equipment of household elect
Popular recommended products
200-500W Switching Power Supply
2020-08-2924-65W Switching Power Supply
2020-08-2912V2ASwitching Power Supply
2020-08-28MKD-571202000 ADAPTER AC ADAPTER CE ADAPTOR UL ADAPTOR Linear Adapter
2020-08-28MKA-571652420 ADAPTER AC ADAPTER CE ADAPTOR UL ADAPTOR Linear Adapter
2020-08-28EI-66 ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Power Adapter Linear Adapter
2020-08-28EI-57 ADAPTER LINEAR ADAPTOR Linear Power Adapter Switching Power Adapter INTERCHANGEABLE ADAPTOR Li
2020-08-28EI-48 ADAPTER LINEAR ADAPTOR Switching Power Adapter INTERCHANGEABLE ADAPTOR Linear Adapter
2020-08-28EI-41 ADAPTER AC ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Adapter
2020-08-28EI-35 ADAPTER AC ADAPTER SWITCHING ADAPTOR Linear Power Adapter Linear Adapter
2020-08-28ER42 High Frequency Transformer
2020-08-2712-36W POE POWER SUPPLY
2020-08-27Transformer,Power Transformer,Ring Power Transformer
2020-08-27Transformer，High Frequency Transformer，Frequency Transformer
2020-08-2712-24W Medical Switching Power Supply
2020-08-273-12W Medical Switching Power Supply 3W Switching Power Supply 12W Power Supply
2020-08-2745W PD Charger,45W Charger,PD Charger
2020-08-2736-90W Charger,36W Charger,90W Charger,40W Charger,50W Charger
2020-08-2724W USB Charger,24W Charger,USB Charger
2020-08-2724W 2USB Charger,24W Charger ,2USB Charger
2020-08-2710-24W Charger,24W Charger,10W Charger
2020-08-2730-500W LED Power Supply 30-500W Power Supply
2020-08-27Related Information
What are the unique advantages of high frequency switching power adapter
2022-04-20General Mechanism Analysis of Switching Power Adapter.ac power adapter wholesaler
2022-04-19Suppression method of low frequency ripple of switching power supply
2022-04-16Why is the power adapter making noise?
2022-04-15When the power adapter is in normal use, what is the normal temperature?
2022-04-1490% of people use the car charger incorrectly, are you using it right?CAR POWER SUPPLY sales
2022-04-13The difference between a power adapter and a voltage regulator
2022-04-12Select the power adapter to determine these three adaptation conditions.SWITCHING POWER Vendor
2022-04-11Why is the original power adapter better than the non-original one?TRANSFORMER Production
2022-04-09What are the industries where the power adapter can be applied?CAR CHARGER wholesale
2022-04-08What is the difference between high-end and low-end power adapters? How to check after playing,CAR P
2022-04-07How to design a good power adapter,CAR CHARGER wholesaler
2022-04-07Customized desktop power adapter
2022-04-06The quality of the switching power supply determines the safety of electricity use,CAR CHARGER whole
2022-04-02What are the advantages of wireless chargers?
2022-03-30PD charger is a must-have at home
2022-03-29What are the main materials of the power adapter shell?
2022-03-26What is a PD power adapter? It can make charging ubiquitous
2022-03-25Slow charging? Try a fast charger
2022-03-24Do you understand the cause of abnormal noise in the power adapter?
2022-03-23Reasons for abnormal noise of the power adapter
2022-03-22Talking about the common problems of the power adapter
2022-03-19General manufacturer power adapter reliability test items
2022-03-18More energy efficient and safe power adapter
2022-03-17Five ways to solve the power adapter overheating?
2022-03-16What are the common connection faults of cottage shared chargers on the market?
2022-03-15How to use the car charger and matters needing attention!
2022-03-14Do you know the difference between a power adapter and a charger,CAR CHARGER Processor
2022-03-12The power adapter has a very wide range of applications,Audio Transformer
2022-03-11What is the development trend of the power adapter industry,AC ADAPTER
2022-03-10Popular recommended products
MKS-1202000-36 Switching Power Supply
2020-08-29MKS-1201250HEU Switching Power Supply
2020-08-29MK-C1806028 MKA ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Power Adapter Linear Adapter
2020-08-2840W 4USB Charger,40W Charger,4USB Charger
2020-08-2719V2A 36W Switching Power Supply
2020-08-2830-500W LED Power Supply 30-500W Power Supply
2020-08-2712W 2USB Charger,2USB Charger,12W Charger,USB Charger
2020-08-2760W 6USB Charger,60W Charger,6USB Charger,Charger
2020-08-2730W PD Charger,30W Charger,PD Charger
2020-08-2724-65W Medical Switching Power Supply
2020-08-27Transformer，High Frequency Transformer，Frequency Transformer
2020-08-27500W Charger,Charger
2020-08-2836-65W Switching Power Supply
2020-08-29100-300W Charger,100W Charger,200W Charger,300W Charger
2020-08-27ER42 High Frequency Transformer
2020-08-27MKA-571652420 ADAPTER AC ADAPTER CE ADAPTOR UL ADAPTOR Linear Adapter
2020-08-283-15W Switching Power Supply
2020-08-2824-65W Switching Power Supply
2020-08-293-12W Medical Switching Power Supply 3W Switching Power Supply 12W Power Supply
2020-08-27MKS-120200BS-36 Switching Power Supply
2020-08-2936-90W Charger,36W Charger,90W Charger,40W Charger,50W Charger
2020-08-27EI-66 ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Power Adapter Linear Adapter
2020-08-28MKS-120200EU-36 Switching Power Supply
2020-08-2912-36W POE POWER SUPPLY
2020-08-2712-24W Medical Switching Power Supply
2020-08-27EI-28 AC ADAPTER LINEAR ADAPTOR Linear Power Adapter Switching Power Adapter Linear Adapter
2020-08-28EI-41 ADAPTER AC ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Adapter
2020-08-2845W PD Charger,45W Charger,PD Charger
2020-08-2712W CAR CHARGER,12W USB CAR CHARGER,CAR CHARGER,12W CHARGER
2020-08-2712VDC8A 96W power supply
2020-08-28