The continuous conduction harassment nominal measuring frequency range of home appliance products 148.5 kHz-30MHz, the actual is 150 kHz-30MHz, the measurement is to be done on power terminal, load terminal and additional terminal.
The main source of continuous conduction harassment
The switch frequency and harmonic disturbance of switch power supply, the rectifier noise of power rectifier circuit, AC motor operation noise, DC motor brush noise, the electromagnetic disturbance of electromagnetic induction heating equipment, the crystal oscillator of Intelligent control equipment and the electromagnetic disturbance of digital circuit etc. (Related testing equipment of Lisun Group: EMC Testing Equipment)
When we find the point of exceeding standard, through harassment locating mode, then the corresponding disturbance suppression measures can be taken. (The explanation is made respectively according to the fault location and the sources of conduction disturbance).
For the ordinary continuous conduction harassment of Power end, it can be controlled by the following circuit,
For the conduction harassment of load terminal and additional terminal, it can be controlled by the following circuit.
No matter whether we take measures to the power terminal, load terminal and additional terminal, if the independent filter is used, we have to pay attention to its installation.