Selection of some components

abr's picture
abr

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Joined: May 17, 2021

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Selection of some components
May 17, 2021 - 11:16am

Night light project. (My first project.)

 

I need some help to select some components.

 

I have a 240 VAC/50 Hz voltage supplying a Bridge Rectifier (4x1N4007) with an output of 24VDC for 6 blue LED in series.

 

I have to step down the voltage from 240VAC to 24VDC.  I don’t know how drop the voltage from 240VAC to 24VAC.  It is where I need some help.

 

From what I read, to step down the voltage, I need a Cx capacitor (?? µf 400V) and one resistor R1 (??Ω) in parallel  to discharge the capacitor and another R2  (??Ω) resistor on the other side.

 

 

I know the Bridge Rectifiers change the current from AC to DC and I will need another C1 capacitor to smooth the ripples and a resistor of R3 (120 Ω) before my 6 LED.

 

I could use the values already available on different websites but I would like know the step by step for selecting the Cx Capacitor and the 2 resistors before the Bridge Rectifier.

 

Thank you.

Sourav Gupta's picture

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Joined: Feb 12, 2018

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I think this question is addressed in another forum thread.

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abr

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Hi Sourav.  Yes, you are correct, I did post the same request elsewhere as I could not get the information that I am seeking.  I am looking for some guidance to put me in the right direction as my knowledge in electronic is limited.  Can I be blamed for being persistant at understanding how things work?  Regards

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