connection of a inductor and a resistance

[shaswat]

**broken link removed**



Guys i have a question regarding the schematic shown on the above link. The above link shows the schematic diagram of iWatt 1810 power supply. I want to know that why they connect a inductor with the resistance after the bridge rectifier.What is the purpose of connecting such a components.Is it used to limit the current or something I missing.

I want to let you know that i am new in this field and i don't have enough knowledge. I am not electronic genius so please help me in solving such a stuff...

 

[t_maggot]

Maybe the designer has put this resistor as a damper for possible resonant oscillations in the rectifier output pi filter that C5, L1 and C2 (and bead inductor) form. Because if you combine the capacitors, essentially you get one parallel RLC circuit in which the damping factor \[\zeta=\frac{1}{2R} \sqrt{ \frac{L}{C} }\] is inversely proportional to the resistor value. Just a guess of course.

 

[shaswat]

Ahh...... I don't know but your answer makes me little doubtful and confuse. What is the requirement of using (If talking about the RLC combination) in this circuit?Does it makes any sense??If yes then please elaborate as may be I am not getting what you want to say

 

[t_maggot]

Using a CLC (https://en.wikipedia.org/wiki/Capacitor-input_filter) filter instead of a single capacitor in the output of the diode rectifier bridge (https://en.wikipedia.org/wiki/Diode_bridge) has some advantages, so the designer choose to use it for his reasons (the reasons can include ripple (https://en.wikipedia.org/wiki/Ripple_(electrical)), EMC compliance, component costs, board space etc).

But combining a capacitor and an inductor can cause resonanse (https://en.wikipedia.org/wiki/LC_circuit) which is unwanted here.

So, adding the resistor, as a dumper (https://en.wikipedia.org/wiki/Damping) in this RLC (https://en.wikipedia.org/wiki/RLC_circuit#Parallel_RLC_circuit) can help to reduce these oscillations.

Hope this makes sense

 

[shaswat]

thanxxx..........................I got your point

 

[kgavionics]

afford you self a kind of big capacitor 1000uF and obove and you will get a descent power supply.

 

[shaswat]

1000uF results more VA losses........................