13 Volt 20 Amp with current limiter

This PSU has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. The power transformer should be capable to deliver at least 25A at 17.5 to 20V. The lower the voltage, the lower power dissipation. The rectified current will be ironed by the C1, whose capacity should not be less than 40.000uF.

The power supply unit (PSU) described is engineered specifically for high-demand applications, such as ham radio transceivers, which require substantial current to operate effectively. The output specification of 20 Amperes at a nominal voltage of 13.8 Volts is critical for ensuring that these devices function reliably under load.

To accommodate varying current requirements, the PSU incorporates a separate current-limiting output. This output is designed to provide a maximum current of 15 milliamperes, with the capability to scale up to a total output of 20 Amperes. This feature is particularly beneficial for protecting sensitive components during startup or when operating under fluctuating load conditions.

The power transformer selected for this design must have a minimum current rating of 25 Amperes and an output voltage range of 17.5 to 20 Volts. This specification is crucial as it allows for adequate headroom to ensure that the rectification and filtering stages can operate efficiently without exceeding the transformer’s ratings. The relationship between the output voltage and power dissipation is also significant; lower output voltages reduce power loss within the system, enhancing overall efficiency.

The rectification process is facilitated by a capacitor, designated as C1, which plays a vital role in smoothing the output voltage after rectification. The capacitor must have a capacitance rating of no less than 40,000 microfarads (uF). This large capacitance is necessary to minimize voltage ripple and maintain a stable DC output, which is essential for the reliable operation of sensitive radio equipment.

In summary, the PSU design integrates robust components and specifications to ensure reliability and performance in high-current applications, particularly for ham radio transceivers. The careful selection of the transformer, current limiting features, and substantial filtering capacitance collectively contribute to the effective operation of the power supply under demanding conditions.This PSU has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. The power transformer should be capable to deliver at least 25A at 17.5 to 20V. The lower the voltage, the lower power dissipation. The rectified current will be ironed by the C1, whose capacity should not be less than 40.000uF, (a golden 🔗 External reference