320volt / Zener Power Supply Calculator

Zener Power Supply Calculator

zener-power-supply-calculator-schematic


Input voltage Max.: V
Input voltage Min.: V
Output voltage: V
Load current: mA
    Calculated Values:
R1 Resistor Value: Ohm      Watt
D1 Zener Value: Volt       Watt

NOTE: Zener is calculated as the value of using more than 0.1 volts, for example, ultimately resulting to 5v regulated 5v zener 5.1V zener will use the application.

zener-diyot-direcn-regulator

Zener Diode and resistor selection

Choosing a zener diode and resistor:

The zener voltage Vz is the output voltage required
The input voltage Vs must be a few volts greater than Vz
(this is to allow for small fluctuations in Vs due to ripple)
The maximum current Imax is the output current required plus 10%
The zener power Pz is determined by the maximum current: Pz > Vz × Imax
The resistor resistance: R = (Vs – Vz) / Imax
The resistor power rating: P > (Vs – Vz) × Imax

Example: Zener diode regulator output voltage required is 5V, output current required is 60mA.

Vz = 4.7V (nearest value available)
Vs = 8V (it must be a few volts greater than Vz)
Imax = 66mA (output current plus 10%)
Pz > 4.7V × 66mA = 310mW, choose Pz = 400mW
R = (8V – 4.7V) / 66mA = 0.05kohm = 50ohm, choose R = 47ohm

zener reg. info source: http://www.kpsec.freeuk.com/powersup.htm