Power Supply Characteristics

There are numerous factors that determine the caliber of the charged power supply such as the load voltage, load present, voltage regulation, source regulation, output impedance, ripple rejection, and so on. Some of the characteristics are shortly explained below:

1. Load Regulation – The load regulation or load effect is the change in regulated output voltage when the load current changes from minimum to maximum value.

Load regulation = Vno-load – Vfull-load

Vno-load – Load Voltage at no load

Vfull-load – Load voltage at full load.

From the equation that is above can understand that when Vno-load does occur the load opposition is endless, that is, the away terminals are available circuited. Vfull-load occurs when the load opposition is for the value that is minimal voltage legislation is lost.

% Load Regulation = [(Vno-load – Vfull-load)/Vfull-load] * 100

2. Minimum Load Resistance – The load resistance at which a power supply delivers its full-load rated current at rated voltage is referred to as minimum load resistance.

Minimum Load Resistance = Vfull-load/Ifull-load

The value of Ifull-load, full load current should never increase than that mentioned in the data sheet of the power supply.

3. Source/Line Regulation – In the block diagram, the input line voltage has a nominal value of 230 Volts but in practice, here are considerable variations in ac supply mains voltage. Since this ac supply mains voltage is the input to the ordinary power supply, the filtered output of the bridge rectifier is almost directly proportional to the ac mains voltage.

The source regulation is defined as the change in regulated output voltage for a specified rage of lie voltage.

4. Output Impedance – A regulated power supply is a very stiff dc voltage source. This means that the output resistance is very small. Even though the external load resistance is varied, almost no change is seen in the load voltage. An ideal voltage source has an output impedance of zero.

5. Ripple Rejection – Voltage regulators stabilize the output voltage against variations in input voltage. Ripple is equivalent to a periodic variation in the input voltage. Thus,a voltage regulator attenuates the ripple that comes in with the unregulated input voltage. Since a voltage regulator uses negative feedback, the distortion is reduced by the same factor as the gain.