![]() ![]() Two inductors (EMI_元 and EMI_L4) are then used to make the LC arrangement on the positive rail.īetween 8W and 40W: An X-Capacitor is used (EMI_CX), and two Inductors are added on the AC side (EMI_L1, and EMI_L2). The input capacitance is divided into two capacitors (CIN1, CIN2). Lower than 8W: 2 LC filters are used after the rectifier. To help evaluate the impact of adding CAPZero, the dialog displays the worst case standby power dissipation of RX1+RX2 resistors or RX1+RX2+CAPZero, calculated at maximum line voltage.įor LED applications, the following filters are used: If Allow use of CAPZero is set to YES, PI Expert automatically adds a CAPZero device to the circuit when appropriate. CAPZero is a specialized Automatic X Capacitor Discharge IC to dramatically reduce dissipation from these resistors. The dialog displays the worst case additional standby power dissipation from these components.Ī side effect of adding RX1 and RX2 resistors for X capacitor discharge is a small amount of additional power dissipation, which degrades no load power consumption. PI Expert automatically adds resistors RX1 and RX2 to discharge the X capacitor and a CAPZero device to minimize their no-load power consumption. IEC950 standard requires that all capacitors larger than 0.1uF, which are connected to external mains, have a means of discharge for pluggable equipment of type A. Greater than 27 W: the size of the default X capacitor becomes larger than 0.1uF. Greater than 20 W: an X capacitor (CX) is placed between Line and Neutral which then has a common mode choke (LCM) placed before the bridge rectifier which feeds the bulk capacitor (CIN1).The default size of the X capacitor depends on the output power of the converter. An appropriate inductor (L1) is then inserted between the two capacitors in the DC plus rail.īetween 3 W and 5 W: PI Expert uses a π (pi) filter arrangement similar to the one above only with an inductor (L2) in the DC return in addition to the DC plus rail.īetween 5W and 10 W: a further modification to the π (pi) filter previously used is made whereby a resistor (R1) is placed in parallel with the inductance present in the return rail.īetween 10 W and 20 W: a common mode choke (LCM) is used in a π (pi) filter-like arrangement inserted between the two bulk capacitors (CIN1, CIN2). PI Expert separates the input capacitance into two capacitors (CIN1, CIN2) with equivalent capacitance that is greater than or equal to the minimum input capacitance (CMIN). Lower than 3 W: a simple π (pi) filter arrangement is used. For non-LED applications with standard bulk capacitors the following filters are automatically selected: PI Expert selects the most appropriate filter circuit based on the output power and the type of application. There are five different EMI circuits that PI Expert uses. PI Expert provides a starting base for a conducted EMI filter. Use the EMI Filter form to review and edit the EMI circuit configuration. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |