How to Convert 4.8V DC to 1.2V DC for Your Device

Understanding Your Requirement

Does your device really need 1.2V? This is an unusual voltage, and we recommend verifying the necessity of this value. If your device will not function properly at a different voltage, you may need to continue with the conversion.

Estimating Current Draw

To proceed, you should first understand how much current your device will draw at 1.2V. This is crucial because different conversion methods can handle different current levels.

Options for Voltage Conversion

1. Using an Adjustable Voltage Regulator

If you need to maintain a more specific voltage, you might consider using an adjustable voltage regulator. A popular choice for this is the LM317. Here are the steps to use it:

Connect a 0.1uF capacitor across the input and output pins of the LM317, and a 10uF capacitor across the output and ground pins. Connect a 220-ohm resistor between the output and the adjust pins of the LM317. Connect the input of the voltage regulator to the 4.8V DC supply and the output to your load that requires 1.2V.

The output will be a stable 1.2V supply, even if the input voltage varies. Remember, the LM317 has a rated current capacity of 1.5A, so ensure your load requirement does not exceed this limit.

2. Using a Resistor Divider Network (for Low Current)

For lower current applications, you can use a simple resistor divider network. You would need to drop 3.6V from the 4.8V input to achieve the 1.2V output. A simple calculation can help you determine the resistor values required.

3. Utilizing Diodes in Series (for Higher Current)

The diode method can be effective for higher current requirements. You can connect five diodes in series with the positive output of your 4.8V supply. Diodes typically drop about 0.7V each, so five in series would drop approximately 3.5V, which is close to the desired 1.2V.

Switch Mode Conversion for High Efficiency

For higher current requirements or to achieve higher efficiency, a switch mode step-down converter (buck converter) is recommended. A switch mode converter can provide a stable 1.2V output with higher efficiency, minimizing heat dissipation and allowing for a more efficient use of power.

Advantages of Switch Mode Converters

Higher efficiency (typically 80-90%) Lower heat dissipation and reduced heat management issues Capable of handling higher current loads

By providing a high efficiency switching step-down converter, you can achieve a stable 1.2V output even with a 4.8V input, ensuring that your load receives the correct voltage without waste.

Conclusion

Depending on your current needs and the specific requirements of your device, you can choose the appropriate method for converting 4.8V DC to 1.2V DC. Whether it's a simple resistor divider, diode drops, or a switch mode converter, there are several approaches that can be tailored to your needs.