Is it a malfunction even if the switching power supply is output? I may think.
The sound is different from usual, what does it smell like, it’s hot, maybe it’s because of my mind?
Please refer to the causes and countermeasures for each of the common symptoms.
Abnormal noise
Fan
As the grease in the fan bearing deteriorates (hardens), it loses its function as a lubricant. Therefore, as the fan rotates, a larger force (torque) is required and the fan rotation noise becomes louder.
If the fan makes a strange noise, replace the fan.
The life of the fan at an ambient temperature of 40 ° C is about 4 to 5 years. It will last faster in a dusty environment.
* The fan manufacturer’s definition of life is when the rotation speed reaches 70% of the rated rotation speed. The time when the fan stops is not the life of the fan.
Trance
Since the core of the transformer vibrates, it makes a “boom” or “keen” sound, but it is usually not noticeable. There is no problem with the power supply itself.
However, if it is too large, it will be returned to the manufacturer.
Harmonic current suppression circuit
A power supply with a harmonic current suppression circuit may make a humming noise when the input is turned on. It is temporary until the internal voltage stabilizes and is not a malfunction.
Offensive odor (white smoke rises)
If the pressure inside the electrolytic capacitor rises for some reason, the “explosion-proof valve” of the electrolytic capacitor will open to release the pressure. At that time, a “shoe” sound is heard and white smoke rises and gives off a strange odor, so people who see it for the first time mistake it for smoke.
The power supply is out of order, so replace it with a new one.
Since it is a phenomenon that does not occur normally, ask the manufacturer to analyze it.
If an overvoltage is applied to the electrolytic capacitor, the internal pressure may increase. The explosion-proof valve opens to reduce the internal pressure before the electrolytic capacitor explodes. The explosion-proof valve has a slit (notch) in the head of the electrolytic capacitor, and the shape of the slit differs depending on the manufacturer. When the explosion-proof valve is opened, the gas inside is released, so smoke is emitted and there is a strange odor, so many people mistakenly think that it has “smoke”. The opening of the explosion-proof valve is proof that the safety device worked normally.
異常発熱
The power supply heats up because it transfers heat to the housing (chassis, cover) for heat dissipation.
If the temperature inside the power supply rises too high, overheat protection will work and the output will stop.
To lower the temperature of the power supply, change the power supply to one with a larger capacity (lower the load factor), change the location and orientation of the power supply, and open a slit in the housing to allow heat to escape.
Smoke / ignition
Since the parts used in switching power supplies are flame-retardant, they are unlikely to ignite due to smoke.
By the time it has protection, it is designed to stop safely.
However, usage outside the warranty, usage environment, and some adverse conditions may overlap.
In the unlikely event that smoke or fire occurs, immediately turn off the input and return it to the manufacturer as it is without touching anything.
LED blinking
Overcurrent protection is working.
When the output current exceeds the rated current value, overcurrent protection is activated, the voltage drops, and the LED turns off. When the output current drops, the output voltage also returns and the LED lights up. This is repeated.
The power supply is working properly.
Since the load is heavy, change the power supply to one with a large capacity.
When the peak current flows at startup like a motor, select the power supply based on the peak current value.
Overcurrent protection works when the power supply is selected with a constant current.
LED Off
The power is not output when the LED is off. Check input voltage, overvoltage protection, sensing, remote control, etc
Not entered
The proper voltage is not input to the power supply.
The fuse on the power input side may be blown or the breaker may be tripped.
If the fuse is blown, replace it and return the breaker. Check the wiring just in case.
Overvoltage protection working
When the overvoltage protection is activated, the output will stop.
The output voltage of the constant voltage power supply does not rise.
The cause is that overvoltage protection operates when a voltage (counter electromotive voltage) is applied from the load side.
The counter electromotive voltage is the voltage applied to the power supply side when the current of the motor changes significantly when the load is a motor. Actually, the reproduction experiment is difficult.
After taking measures against them, turn off the input and re-enter.
If it still does not output, the power supply itself may be defective and will be returned to the manufacturer.
Sensing terminal is open
For power supplies with a sensing function, if the sensing terminals (+ S, -S) are open, the output voltage rises and overvoltage protection operates and the output stops.
Connect the sensing terminal to the load, or connect the sensing terminal to the output terminal (+ V, -V) of the power supply with a short piece.
Remote ON / OFF control is OFF
When the OFF signal is output to the power supply by remote control, the power supply stops.
The OFF signal can be turned off with the power input by inputting a voltage of 0.5V or less to the connector.
Returns the remote control signal from OFF to ON.
Fan abnormality
Stop
In addition to fan failure, the power supply fan stops when the load is light (10% or less) and when the remote control function is OFF.
The power supply itself is normal.
Abnormal noise
It is the same as the “abnormal noise (fan)” mentioned above.
Output error
Output stop
Same as “LED goes off” above.
High output voltage
The variable output voltage volume is turning to the right (clockwise).
Return the variable output voltage volume to the left (counterclockwise).
The output voltage is low
Measure the voltage on the power supply side, not the voltage on the device side.
The variable output voltage volume is turning to the left (counterclockwise).
Return the variable output voltage volume to the right (clockwise).
Alternatively, the capacity of the electrolytic capacitor may be lost (life).
Replace the power supply.
Output voltage is unstable
Overcurrent protection is working.
When the output current exceeds the rated current value, the overcurrent protection works and the voltage drops, and when the output current drops, the output voltage returns to the original value. Repeat this.
The power supply is operating normally, so change the capacity of the power supply to a larger one.
This is the end of the article.
Repair and analysis methods differ depending on the manufacturer, so please check before requesting.
Thank you for reading.