Calculateur de Gain d'AOP Inverseur
Calculez le gain d'un amplificateur opérationnel inverseur.
Series Resistor
276.0 Ω
Series Resistor vs Input Voltage
Formule
## Zener Diode Voltage Regulator A zener diode in reverse breakdown maintains a nearly constant voltage. ### Formula **R_series = (V_in - V_zener) / (I_load + I_zener_min)** The resistor drops excess voltage. The zener must carry at least its minimum current for proper regulation even at full load.
Exemple Résolu
Regulate 12 V down to 5.1 V for a 20 mA load. Zener needs 5 mA minimum.
- 01Total current = (20 + 5) / 1000 = 0.025 A
- 02R = (12 - 5.1) / 0.025 = 276 ohms
- 03Resistor power = 6.9 x 0.025 x 1000 = 172.5 mW
- 04Zener power = 5.1 x 0.025 x 1000 = 127.5 mW
Questions Fréquentes
When should I use a zener regulator?
For low-current loads under 100 mA where simplicity matters more than efficiency. For higher currents use a linear or switching regulator.
Why does the zener need minimum current?
Below its minimum reverse current the zener does not maintain a stable breakdown voltage and regulation fails.
How do I choose the zener wattage?
Use at least 2x the calculated zener power for safety margin. Common ratings are 250 mW, 500 mW, and 1 W.
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