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VOLTAGE REGULATOR PowerPoint Presentation
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VOLTAGE REGULATOR

VOLTAGE REGULATOR

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VOLTAGE REGULATOR

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    1. VOLTAGE REGULATOR

    2. Voltage Regulator Zener diode is a voltage regulator device because it is able to fix the output voltage at a constant value (DC voltage). RS is to limit the zener current, IZ so that it is less than the maximum current, IZM (to avoid the zener diode from broken).

    3. Zener as Regulator

    4. Voltage Regulator How to determine whether the zener acts as a regulator or not?? Use Thevenin Theorem See example If VTH<VZ, regulation does not occur.

    5. Voltage Regulator. Referring to zener I-V charateristic curve, if the voltage across the zener diode zener is between 0-VZ, the zener diode is operating in the reverse bias region, thus it DOES NOT functioned as a regulator. VTH must at least the same value as VZ (VTH ? VZ) so that the diode CAN function as a voltage regulator because it is operating in reverse breakdown region.

    6. Zener I-V Charateristic

    7. Zener Diode Regulator

    8. Thevenin Equivalent Circuit

    9. Examples of zener as voltage regulator

    10. Cases in Zener Regulator Circuits

    11. Zener Diode Three types of Zener analysis Fixed VS and RL Fixed VS and variable RL Variable VS and fixed RL

    12. Zener Diode - Fixed VS and RL

    13. Zener Diode

    14. Zener Diode - Fixed VS and Variable RL

    15. Zener Diode

    16. Zener Diode - Variable VS and fixed RL

    17. Zener Diode

    18. IC Regulator The 78xx (also sometimes known as LM78xx) series of devices is a family of self-contained fixed linear voltage regulator IC. The 78xx family is a very popular choice for many electronic circuits which require a regulated power supply, due to: i. ease of use and ii. Low cost.

    19. 78xx and 79xx IC When specifying individual ICs within this family, the xx is replaced with a two-digit number, which indicates the output voltage the particular device is designed to provide (for example, the 7805 has a 5 volt output, while the 7812 produces 12 volts). The 78xx line are positive voltage regulators, meaning that they are designed to produce a voltage that is positive relative to a common ground. There is a related line of 79xx devices which are complementary negative voltage regulators. 78xx and 79xx ICs can be used in combination to provide both positive and negative supply voltages in the same circuit, if necessary.