Dimensioning of DC power supply with not stabilized output using a full-wave rectifier realized by a Graetz silicon bridge and capacitive filter of leveling for ripple reduction (residual waving).
Nominal voltage of the PRIMARY winding
V ac NOM
Nominal voltage of the SECONDARY winding
V ac NOM
Nominal power of the transformer
50 Hz (sinusoidal)
60 Hz (sinusoidal)
Total capacity of the filter capacitors . . . C
Define automatically an appropriate capacity
based on the above data
Real supply voltage:
V ac EFF
Real applied load:
|Theoretical transformation ratio|
|Percentage of characteristic voltage drop relative to the nominal transformer power||%|
|Secondary no-load voltage with real applied supply voltage||V max|
|Voltage drop of the secondary winding relative to the applied load||V ac|
|Real output voltage of the secondary relative to the applied load||V ac EFF|
|Peak-to-peak secondary voltage related to the applied load||V PEP|
|Rectifier + capacitive filter :|
|Rectified voltage related to the applied load||Vp|
|RMS rectified voltage related to the applied load||V EFF|
|Output ripple related to the applied load and to the filter capacity choosed||Vrpp|
|Considered voltage drop of the rectifier||V|
|Minimal power dispersed by the rectifier (bridge) with the applied load||W (diodes)|
Voltage drop on the secondary caused by the load can change in function of construction or designing of the transformator itself.
The no-load output voltage of the transformator is obtained summing the expected drop at the maximum power at the nominal voltage. Pratically the output voltage at the nominal power will be equals to the nominal voltage.
The output ripple (Vrpp) can change in function of the quality of the used capacitors.
The ripple value (Vrpp) is made reasonably valid up to 50% of V RMS, beyond this value the inaccuracy increases.
Normally a supply must be able to work correctly with supply voltages which can change at least of +/- 10% respect to the nominal or the project value.