in order to convert the AC supply to DC supply for the internal circuit, normally a rectifier is needed. But the output of the rectifier can not be a constant and always has the ripples.
Are there any methodes to minimize the ripples after the rectifier?
Or is it possible to obtain a constant voltage after the rectifier? for example, to use a voltage regulator?
After the rectifier you need a capacitor, mostly an polarized capacitor, make the 100 or 120Hz (2x 50 / 2x60Hz) ripple smaller. After that you can use a linear voltage regulator, resistor/zener, switchmode regulator etc to make the ripple small enough for your application.
The value of the pol. capacitor depends mainly of the current you need for your application.
As far as ripple rejection is concerned there is no better alternative as voltage regulators - on average they offer at least 60dB ripple attenuation ..
One can only dream of similar result while using passive components such as smoothing capacitors, RC or LC filters, not to mention another important feature, namely constant output voltage vs. connected loads ..
are there any more detailed information or reference regarding the design of voltage regulator for this application?
thanks
IanP said:
As far as ripple rejection is concerned there is no better alternative as voltage regulators - on average they offer at least 60dB ripple attenuation ..
One can only dream of similar result while using passive components such as smoothing capacitors, RC or LC filters, not to mention another important feature, namely constant output voltage vs. connected loads ..