Switzerland the switching frequency of the AC-DC switching power supply module?(4)
When testing electronic and electrical equipment, the electronic and electrical equipment shall be tested for conducted interference voltage emission at its Marine boost power supply terminal. Although the test frequency bands of different standards are different, the test frequency bands of most products are 150K~30M. It can be seen from the lower limit of the test frequency that the operating frequency of the switching Marine boost power supply is close to 150K, and the more difficult it is to deal with the conducted disturbance.
3. What special applications are required for the power switching frequency?
In some special cases, the circuit operation is more sensitive to the switching noise of the Marine boost power supply. Such as power carrier, wireless communication, wireless identification, etc. The Marine boost power supply requirements for power carrier applications are as follows.
Remote control switch circuit
The remote control switch operation of the module power supply is carried out through the REM terminal. There are two general control methods:
(1) REM is connected to -VIN (reference ground), the remote control is turned off, and VREF<0.4V is required. REM is suspended or connected to +VIN, the module works, and VREM>1V is required.
(2) REM is connected to VIN, the remote control is turned off, and VREM<0.4V is required. REM is connected to +VIN, the module works, VREM>1V is required. REM is suspended, and the remote control is turned off, that is, the so-called "suspended shutdown" (-R).
If the control is to be isolated from the input, an optocoupler can be used to pass the control signal
At present, the power carrier is mainly used for intelligent carrier in the home, remote meter reading system, and remote street lamp control system. The use range of the carrier frequency of power lines in my country is 9KHz ~ 500KHz, and the carrier bandwidth is 4KHz. The development of power carrier is very limited due to the change of power line impedance and the interference of power line noise. In order to increase the communication distance of the power carrier, we must move away from the power switching frequency of the circuit carrier unit. The carrier frequencies currently used in China are 115KHz and 132KHz. In this case, the switching frequency is around 60KHz for the Marine boost power supply.