Cómo resolver el problema de exceso radiación de conmutación potencia suministro
Dentro de 1MHz:
Principalmente diferencial modo interferencia 1. Aumento X capacitancia; 2. Añadir diferencial modo inductancia; 3. Pequeño potencia alimentación puede ser procesado por PI filtro (it es recomendado que el electrolítico condensador cerca a el transformador debería ser mayor).
1M-5MHz:
Diferencial modo y común modo mezcla, usando el entrada terminal y a serie de X condensadores a filtrar salir el diferencial interferencia y analizar que tipo de interferencia excede el estándar y resolverlo;
5MHz:
The above is mainly based on co-mouse interference, and the method of suppressing co-mouse is adopted. Para la caja puesta a tierra, usando a magnético anillo on la tierra cable para 2 vueltas will greatly atenuate the interference above 10MHZ (diudiu2006); for 25--30MHZ, you can increase the Y capacitor to the ground and wrap copper skin outside the transformer , Change PCBLAYOUT, connect a small magnetic ring with two wires in parallel in front of the output line, at least 10 turns, and connect an RC filter at both ends of the output rectifier tube.
1M-5MHZ:
Differential-mode common-mode mixing, using a series of X capacitors in parallel at the input to filter out differential-mode interference and analyze which kind of interference exceeds the standard and solve it. 1. For differential-mode interference exceeding the standard, you can adjust the X capacitance and add a differential-mode inductor , to adjust the differential mode inductance; 2. For common mode interference exceeding the standard, common mode inductance can be added, and a reasonable inductance can be selected to suppress it; 3. The characteristics of the rectifier diode can also be changed to deal with a pair of fast diodes such as FR107 and a pair of ordinary rectifier diodes 1N4007 .
Por encima 5MHz:
Focus on co-moting interference, and adopt the method of suppressing co-moting.
For the grounding of the shell, using a magnetic ring in series on the ground wire for 2-3 turns will have a mayor attenuation effect on interference above 10MHZ; you can choose to stick copper foil to the iron core of the transformer, and the copper foil is closed-loop. Deal with the size of the snubber circuit of the back-end output rectifier and the parallel capacitance of the primary grande circuito.
For 20M-30MHz:
1. Para a clase de productos, u puede ajustar la capacitancia de Y2 a tierra o cambio la posición de Y2 capacitancia;
2. Ajustar el Y1 condensador posición y parámetro valor entre el primario y secundario lados;
3. Wrap copper foil on the outside of the transformer; add a shielding layer to the innermost layer of the transformer; adjust the arrangement of the windings of the transformer.
4. Cambiar el PCB Diseño;
5. In front of the output line, connect a small common-mode inductor with double-wire parallel winding;
6. Conectar RC filtros entrada paralelo at ambos extremos de el salida rectificador y ajustar razonable parámetros;
7. Add BEADCORE between the transformer and MOSFET;
8. Add a small capacitor to the input voltage pin of the transformer.
9. Tú puede aumentar el MOS unidad resistencia.
30M-50MHz:
1. It is generally caused by the high-speed turn-on and turn-off of MOS tubes. It can be solved by increasing the MOS drive resistance, using 1N4007 slow tubes for the RCD buffer circuit, and using 1N4007 slow tubes for the VCC supply voltage.
2. RCD buffer circuito adopta 1N4007 slow tube;
3. El VCC potencia alimentación voltaje es resuelto por 1N4007 lento tubo;
4. O el frente extremo de la salida línea es conectado en serie con a pequeño común modo inductor con dos cables enrollados en paralelo;
5. Conectar a small snubber circuit in parallel with the D-S pin of the MOSFET;
6. Add BEADCORE between the transformer and MOSFET;
7. Add a small capacitor to the input voltage pin of the transformer;
8. When PCB LAYOUT, the circuit loop composed of large electrolytic capacitors, transformers and MOS should be as small as possible;
9. El circuito bucle compuesto de transformador, salida diodo y salida suavizado electrolítico condensador debería ser as pequeño as posible.
50M-100MHZ:
It is generally caused by the reverse recovery current of the output rectifier tube,
1. Magnético cuentas puede ser encordado on el rectificador tubo;
2. Ajustar el absorbente circuito parámetros de la salida rectificador;
3. La impedancia de la primaria y secundaria lado across la Y condensador rama puede ser cambiado, such as adding BEADCORE a la PIN pin or connecting an apropiada resistor in series;
4. It is also possible to change the MOSFET to output the radiation from the body of the rectifier diode to the space (such as the iron clip MOSFET; the iron clip DIODE, change the grounding point of the radiator).
5. Agregar blindaje cobre lámina para suprimir radiación a espacio.
