# Electronic – Full-wave bridge rectifier with capacitor filter and ripple voltage

filterrectifierripple

According to various sources, the ripple voltage of a full-wave bridge rectifier is

$$V_r = \frac{V_s}{2}fCR$$

where \$V_s\$ is the peak of the input voltage source, \$f\$ is the frequency, \$C\$ is the capacitor and \$R\$ the resistor.

I have simulated this circuit on PSPICE, circuitlab, and built it in real life:
https://www.circuitlab.com/circuit/423m43/fullwave-rectifier/

\$R\$ is \$4.7K\$ and \$C\$ is \$10 uF\$. Voltage source is sine wave with \$0 V\$ offset, \$5V\$ amplitude and \$40 Hz\$ frequency.

All 3 experiments give me a ripple voltage of approximately \$0.65V\$, but the formula gives me \$1.330 V\$ (twice as much).

What am I missing?