Garyl
Full Member level 5
Hey,
I want to design a low noise power supply and I wonder which method is better.
My transformer output is 14V AC at 20VA.
The power supply will be used for ham radio receiver application.
I will most likely feed that power supply to the 7812.
I am considering two solutions.
1. 2nd order RC Low-pass filter
https://www.adpslab.com/en/audio/audio-projects/14-simple-low-ripple-psu-for-dac.html
Schematic:
2. pi-filter
https://www.sunpower-uk.com/glossary/what-is-ripple/
My question is, which is a better solution to reduce the ripple effect and get a stable voltage output?
I want to design a low noise power supply and I wonder which method is better.
My transformer output is 14V AC at 20VA.
The power supply will be used for ham radio receiver application.
I will most likely feed that power supply to the 7812.
I am considering two solutions.
1. 2nd order RC Low-pass filter
https://www.adpslab.com/en/audio/audio-projects/14-simple-low-ripple-psu-for-dac.html
Schematic:
Low pass filter network
The decoupling network is a second order RC low pass filter. This network decreases noise transmission of the high-frequency content of any current that does pass through the resistor. The series elements are 2 small value resistors and DC voltage drop is acceptable because the current is low.
2. pi-filter
https://www.sunpower-uk.com/glossary/what-is-ripple/
A more effective method of reducing the ripple voltage is the addition of a π-filter (pi-filter) at the output of the rectifier. This low pass filter consists of a two smoothing capacitors, as well as a choke to provide high impedance to the ac ripple.
My question is, which is a better solution to reduce the ripple effect and get a stable voltage output?