Help me find the filter capacitor value for my setup

Status
Not open for further replies.
L

Lucifre

Full Member level 2
Joined
Jul 5, 2005
Messages
125
Helped
2
Reputation
4
Reaction score
0
Trophy points
1,296
Location
Detroit MI
Activity points
2,389
I have transformer, bridge rectifier, and LM317T, I am wondering, how do i find the value of the filter capacitor to put before the voltage regulator, and it's voltage rating?
 

Re: Cap question

Voltage rating should be higher than your max output. in your case I think 50V is fine.

For the value you can choose 470 uf.
 

Re: Cap question

For smoothing capacitor capacitance try to use the following formula:
Smoothing capacitor for 10% ripple, C = (5 × Io) /(Vs × f)
Io = output current from the supply
Vs = supply voltage (peak value of unsmoothed DC)
f = frequency of the AC supply (50Hz in UK)
As far as voltage, I woud say 2-2.5 x Max Dc in circuit: example - for 12V ac from transformer use 25Vdc rated capacitor..
More info here: http://www.kpsec.freeuk.com/powersup.htm
Regards,
IanP
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…