Compact and high efficiency power factor correction unit

BPF Series

8

Bellnix

DC-DC Converter

BDD20160127

7. Various functions

7-1 Capacitance of external output capacitor

Output holding time can be extended be connecting external output capacitor. Capacitance of the

capacitor can be calculated using the following expression.

out

P

V

V

C

C

t

/

)

(

)

(

2

1

2

2

2

1

2

1









t: Holding time at instantaneous failure (sec.)

V1: Output voltage=360V (V)

V2: Minimal held voltage at instantaneous failure

(V)

C1: Capacitance of internal capacitor=270uF (F)

C2: Capacitance of external capacitor (F)

Pout: Actual load power (W)

*Select the capacitance of the external capacitor within the range of the maximum load capacitance.

Note that connecting the external capacitor increases the inrush current.

7-2 ON/OFF control

This function allows turning the power factor correction ON and OFF. ON/OFF control of the standby power is

not supported. Setting the ON/OFF terminal (CN3 Pin 2) High or Low (relatively to SGND terminal (CN3 3Pin)) it

is possible to turn the power factor correction function ON or OFF. By combining with the auxiliary power supply,

it is possible to perform ON/OFF control by opening and closing the circuit.

Although the switching operation is stopped when the output is OFF, voltage of approximately 1.41 x input

voltage is generated on output terminal through diode rectification.

Avoid chattering on ON/OFF terminal. The chattering may cause malfunction of internal circuits.

The terminal is connected internally to the light-emitting side (diode) of a photo coupler. (20mA max)

When the ON/OFF control is not used, leave the ON/OFF terminal open or connect it to SGND.

VAUX

ON/OFF

SGND

2.2kΩ

本体内部

外側

SW1

Fig.a Example of connection circuit when the ON/OFF control is used.

SW1 closed: ON, open: OFF

Internal connection

External connection