Q:How to make the switching power supply does not delay power

The relay directly to the circuit off, the big capacitor may be continued to flow about

Q:What is the PWM high-frequency switching power supply

PWM-type high-frequency switching power supply is the use of pulse width modulation (PWM), referred to as pulse width modulation, is the use of microprocessor digital output to control the analog circuit is a very effective technology, widely used in measurement, communication Power control and transformation in many areas of power. PWM switch regulator or steady current power supply basic working principle is in the input voltage changes, internal parameters change, external load changes in the case, the control circuit through the control signal and the difference between the reference signal closed-loop feedback, adjust the main circuit switching device Of the conduction pulse width, making the switching power supply output voltage or current control signal is stable.

Q:12V7A motorcycle battery can not use 14V3A switching power supply charge

Can be used, but can not often use, because: 12V7A battery suitable for the charging current of 0.7-2.1A, 3A current slightly larger. But if you insist on the use of a small change, do not change the original switching power supply, only need a series resistance, resistance size of about 1 ohm, power of 5 wirewound resistors, so that the output current can be controlled within 2.1A, You can also ensure that the battery can be fully charged.

Q:Is switching power and transformer the same thing?

Switching power supply is used to control the switch through the circuit for high-speed pass and cut off. The conversion of direct current into high-frequency alternating current is provided to the transformer for voltage change to produce the required group or groups of voltages. The transformer is voltage-converted by magnetic coupling. The switching power supply is in a field and can not be used instead of the transformer. Output without transformer, rectifier, filter, regulator way pure.

Q:I copied a circuit board, 7W switching power supply, line and the original circuit is exactly the same, that is slightly different alignment, no power after the output. I made two boards, are the same ask, ask the master, where is the problem? How to deal with?

There may be a transformer problem, you have measured the inductance of two transformers is the same, flyback switching power supply is the core to stay in the gap.

Q:I made a switching power supply, using boost dc-dc transform, input 18V, output 30-36V variable. Found that the output voltage has 300mv ripple and 1V burr. Has been added 10mh inductance and 6600uf capacitor filter. Switch tube plus RCD buffer Output with choke and EMI filter,

You said the burr is the overshoot Your inductance is not wrong? 10mH too big? Will it be 10uH wrong? In the out there, the overshoot is sure to exist, but this should be gone in the capacitor This has a lot to do with your measurement 1. Must be in the capacitance of the positive or the amount of load above, do not in the amount of inductance, there is no capacitance 2. With the oscilloscope, the ground connection will have a great impact on the measurement results you can move their own line of the line to see the extent of the test will certainly move The probe on the ground to try to short, the measurement results are correct The above two points to do, the measurement results should not be so big And to be honest, for the 30V output, there are 1V "glitches" that should be acceptable You can check the specifications of other switching power supply, this one usually 5%, 30V * 5% = 1.5V, 1V should be acceptable

Q:Now I want to buy a larger power test power, about 1KW. I have no money, so I want to buy a switching power supply, so that you can save a lot of money, but do not know can not accept the emotional load

Yes, the actual use of a lot. When using the attention, the output connected to a switch, stop, do not directly off the power, you must first disconnect the switch, to avoid inductive load current after the sudden change in the potential to damage the power supply. The above matters, even if other power supply, should be kept as far as possible.

Q:I bought a 3C certification 12V 500mA power adapter, I use 15 ohm 5W resistance to measure the voltage (12V, current 800mA) supposedly the specification is 500mA, more than 600mA should be protected, but why will show 800mA The The In addition, I use 10 ohm resistance to measure it to protect, is not the way I measured is not so measured? Or is this power adapter not 12V 500mA specification but 12V 1A? The The Solve? The Seek test method The

The protection value of the switching power supply is not equal to the rated value, the general protection value is greater than the rated value.

Q:Switching power supply CE certification is probably how much money

Or how much money, there are two or three thousand cheap, you have seven or eight points, of course, the requirements of high, then there are more than ten thousand, specifically look at your needs, look at my name in detail

Q:How to transform the switching power supply, the original AC 220 input into DC 84-100 input output unchanged

If the request is not high, can be used directly, do not change. Switching power supply can be adapted to such a voltage range, if the original undervoltage protection, it will be lowered. Power is not large, you can change the original rectifier part of the voltage rectifier.