Variable Power Supply

 To achieve multiple output voltages from a single 10V transformer, you can use a combination of voltage doubler circuits, regulators, and DC-DC converters. Here's a practical approach:



Variable Power Supply Circuit 

0 to 30 V , 0 to 10 amp

Components Needed:

  1. Voltage Doubler Circuit:

    • Capacitors: Typically, 100µF to 1000µF, 25V.
    • Diodes: 1N4007 or similar rectifier diodes (2 pieces).

    Purpose: Converts 10V AC to approximately 20V DC (after rectification).

  2. DC-DC Buck Converters:

    • For stepping down voltages: Use adjustable or fixed DC-DC buck converters.
    • Common Models: LM2596 (adjustable) or LM2576 for fixed outputs.

  3. Linear Regulators:

    • For specific outputs: 7805 for 5V, 7812 for 12V, etc.
    • Capacitors: Typically 0.33µF and 0.1µF for stability.

  4. Voltage Regulator ICs:

    • LM317 (Adjustable): Can be used for various output voltages (needs external resistors for setting).

  5. Variable Power Supply Homemade

Circuit Design:

  1. Voltage Doubling:

    • Components:
      • 2 × 1N4007 diodes.
      • 2 × 100µF capacitors.
    • Circuit: Connect the AC output from the transformer to the diode-capacitor network to get approximately double the input voltage as DC.

  1. Voltage Regulation:

    • 12V Output: Use a LM7812 regulator.
    • 24V Output: Use the doubled DC (from the voltage doubler) and an LM7824 regulator.
    • 9V Output: Use a LM7809 regulator.
    • 6V Output: Use an adjustable regulator like LM317 or LM7806.
    • 5V Output: Use a LM7805 regulator.
    • 7.5V Output: Use an adjustable regulator like LM317.
    • 3V Output: Use a DC-DC buck converter.
    • 1.5V Output: Use a DC-DC buck converter.

Example Connections:

  • Voltage Doubler:

    • Connect the secondary winding of the transformer to the input of a diode-capacitor network. This will give you approximately 20V DC.

  • Regulated Outputs:

    • 12V: Connect the 20V DC to the input of an LM7812 regulator. Output will be 12V.
    • 5V: Connect to LM7805 regulator.
    • 9V: Connect to LM7809 regulator.
    • 3V and 1.5V: Use adjustable DC-DC buck converters to step down the voltage accordingly.

Useful Links for Better Understanding:

  1. Voltage Doubler Circuit:

  2. Linear Regulators:

  3. DC-DC Converters:

  4. LM317 Adjustable Regulator:

These resources will help you understand the components and how to assemble circuits for various voltage outputs from a single transformer.

      

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