# input current of single phase controlled bridge rectifier

#### cpleng7

Joined Dec 18, 2008
120
May I know how to calculate input current for single phase controlled bridge rectifier?

#### t_n_k

Joined Mar 6, 2009
5,455
It's not that simple, since the current depends on the type of load. For a purely resistive load then a possible solution would be

$$I_{rms}=I_m \sqrt{\frac{1}{2}-\frac{\theta}{2 \pi}+\frac{sin(2 \theta)}{4 \pi}}$$

where Im=peak current & θ= firing delay angle

#### cpleng7

Joined Dec 18, 2008
120
this Irms formula not finding the Irms for the output current?

#### t_n_k

Joined Mar 6, 2009
5,455
The RMS values for load current and input current would be the same.