Home » Forums » Archived: Hardware

Power Supply decoupling

Submitted by Paul Reed on Thu, 14/07/2011 - 19:54

 I am building a 'standalone' 2 channel energy monitor but am a bit stuck with the power supply decoupling.

I am using a LM8705 5v regulator, and whose spec sheet shows 0.33uF on the LM8705 input and 0.1uF on the output, which seem very small capacitance, especially when I see 2 x 47uF caps on my Uno board (I presume that they are used in connection with the power supply).

Any advice please.

‹ How to get your hands on an emonTx kit Achieving good precision with currents of less than 5 A ›
»
Guest's picture

Re: Power Supply decoupling

Submitted by Guest on Thu, 14/07/2011 - 22:12.

What problems are you seeing - and what input is being used to provide your regulator input?

The more variable the input to the regulator, the larger the capacitor at that end you will need

Cheers,

Ben

»
Guest's picture

Re: Power Supply decoupling

Submitted by Guest on Fri, 15/07/2011 - 08:22.

No problems yet Ben because I'm still building it, but want to make sure that I get the values right at design stage.
The input is a 12v transformer supply fed via a rectifier bridge.

»

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.