AN2300

Capacitive converter

Rev1

5/21

1

Capacitive converter

The schematic of the Capacitive power supply is shown in Figure 1. The capacitor C2

accommodates the AC mains voltage to a voltage level suitable for the application, while R1

and R2 are connected in order to limit the inrush current of the capacitors. The voltage is

then rectified by the diode D1 and regulated by means of zener diodes and electrolytic

capacitors. The output capacitor values, C4 and C6, have been chosen in order to keep the

output voltages ripples below 5%, at the given output load condition. The part list of the

converter is given in Table 2.

Figure 1.

Capacitive converter schematic

Table 2.

Capacitive converter part list

Reference

Value

Part type

R1

10

Ω 1/4Ω

Resistor

R2

150K

Ω 1/4Ω

Resistor

C1

47nF

X2 Capacitor

C2

2.2

µF

X2 Capacitor

C3

82nF

Ceramic capacitor

C4

10002

µF, 25V

Electrolytic Capacitor

C5

82nF

Ceramic capacitor

C6

4700

µF, 25V

Electrolytic Capacitor

D1

Diode 1N4007

D2

Diode 1N4007

Dz1

12V

Zener Diode 1N5349B730

Dz2

5.1V

Zener Diode BZX85C5V1

Vin

D1

Dz2

R2

C3

C6

C1

C4

C2

Vout1

Dz1

D2

R1

Neutral

Vout2

Line

C5