Q:Is the DC power supply a switching power supply?

Yes! Modern switching power supply there are two: one is the DC switching power supply; the other is the AC switching power supply. DC power supply that is DC power supply, is to maintain a stable current in the circuit device. Such as dry batteries, batteries, DC generators and so on. DC power supply has positive and negative two electrodes, the potential of the positive pole is high and the potential of the negative electrode is low. When the two electrodes are connected with the circuit, the potential difference between the two electrodes can be kept constant, so that the positive electrode Negative current.

Q:What is the difference between an open switching power supply and an ordinary switching power

Open-type switching power supply generally refers to no sealed shell, and can be cooled by natural air-cooled, all the wind a program to do the power of open switching power supply can do more

Q:Switching power supply, starting resistor is very hot, no output. What is the reason.

That is, switching power supply can not afford to vibrate, if it is self-oscillation to check the rectifier components are not short-circuit, positive feedback circuit is not normal.

Q:Name and function of the components of the switching power supply T1, T2, R11, R12, D6, C2, Q1, D5, U1, U6,

This is a single-ended flyback switching power supply circuit, in this switching power supply, T2 is a high-frequency transformer, the role of voltage conversion, R11 is the starting resistance of U1, the input voltage of 85 - 2-265 AC, the choice should be in the 1--2W, 150 - 330K resistance between, usually need to use multiple resistors in series, otherwise it is easy to damage. R12 is the current limiting resistor of the switch, but also U1 overcurrent current detection resistor, the output short circuit when the voltage drop on the resistor will become high, U1 protection to stop the output drive signal. D6 is the transformer provided to the U1 supply voltage rectifier. C2 is the main filter capacitor, usually with electrolytic capacitors, voltage is greater than the maximum voltage input of 1/3, the capacity of about 1W / micro-law output. Q1 is the FET, is the switch tube. Generally also mos. D5 and R7, C5 are connected to the transformer primary to form the transformer spike voltage absorption circuit. When the switch is turned off, the moment the transformer will have a very high induced voltage generated, this circuit can be absorbed by this spike voltage (or is limited to a safe Of the range). Also called DRC or RCD spike voltage absorption circuit. U1 is the switch tube drive circuit, here should be a PWM integrated circuit, also known as pulse width modulation, is the English "Pulse Width Modulation" abbreviation, referred to as pulse width modulation. U6 is a photocoupler,

Q:Car cd with the battery all right, with a switching power supply speaker has a buzzing sound

Need to use the power supply, switching power supply impurity

Q:Give you a switch on how to look at it is isolated and non-isolated?

With a multimeter input and output side of the resistance, if very small or direct conduction is non-isolated, if the resistance is large, is isolated

Q:Two-wire NPN near switch, switching power supply, and how to connect with Mitsubishi PLC?

Using the source PLC. Close the switch to the common (COM) and input X

Q:Switching power supply how maintenance

1. No output, the fuse is normal This phenomenon shows that the switching power supply is not working or into the protection state. First to measure the power control chip boot pin whether there is a starting voltage, if no start voltage or start voltage is too low, you have to check the starting resistor and start the foot of the external components of the leakage, this time if the power control chip is normal, then the above check You can quickly find the fault. If there is a starting voltage, then the output of the measurement control chip in the boot moment whether there is a high, low level of the jump, if no jump, indicating that the control chip is bad, peripheral oscillator circuit components or protection circuit problems, Chip, and then check the external components; if a jump, the switch is generally bad or damaged. 2. Insurance burn or fry the main inspection 300V on the large filter capacitor, rectifier bridge diodes and switch tubes and other parts, anti-jamming circuit problems can also lead to insurance burn, black. It should be noted that: due to the breakdown of the switch lead to insurance burns will generally be the current detection resistor and power control chip burned. Negative temperature coefficient thermistor is also easy to burn together with insurance. 3. There are output voltage, but the output voltage is too high This failure is generally from the regulator sampling and regulator control circuit. In the DC output, sampling resistor, error sampling amplifier such as TL431, optocoupler, power control chip and other circuits together constitute a closed control loop, any problem will lead to an increase in output voltage. 4. Output voltage is too low In addition to the regulator control circuit will cause the output voltage is low.

Q:Switch power jumper do not know which one which then do?

Motherboard if it is old-fashioned 9-pin is the left side of the HDD LED left and then the left is the POWER LED lower right is restart the rester right power Not the old 9-pin, then the board marked on the plug can be a If it is green black line green line red line red line red line is red line is red!

Q:Switching power input is marked with 220V AC, 36V output, but the actual input voltage is 238V, the output of the switching power supply affect it? Will it damage the switching power supply? Do not know the reason is not the voltage, power after a period of time (10 minutes), the switch power suddenly no output, and the display is not bright, switching power is not already broken? Guiqiu prawn to the doubts!

The actual input voltage at 238V, the output of the switching power supply has no effect, the general input voltage range of 10% or more; "Power after a period of time (10 minutes or so), the switch power suddenly no output, and the display does not light," the switching power supply is already broken