I have a question about "smoothing capacitors". I have a 5v arduino project that will have 6 individual 5v components attached to it. Since I need these running at different times, I wanted to take a similar approach that of Nick Gammon's in his very helpful example (http://www.gammon.com.au/forum/?id=12106) and use a few MOSFETs to switch these little guys on & off individually (instead of the regular arduino pins), while also minimizing any potential power surges that could affect the microcontroller and/or the components themselves. These components are all 5v, and they have a maximum draw of ~170mA when they are all powered on at the same time.
So, if I used 6 different MOSFET switches to turn switch the +5v power line on for each component as directed via the arduino uno, I was wondering:
could I still only use 1 capacitor (like Nick did in his example)?
would a capacitor of 100uF work, or should I use something bigger?
My plan is to first test the circuit with the mosfets & capacitor(s) using a USB, and later on, moving the project to battery power.
These components are all 5v, and they have a maximum draw of ~170mA when they are all powered on at the same time.
Each component must have its own decoupling capacitor (capacitors). How big the capacitor(s) shall be ? That depends fully on the dynamic parameters of the component (the load).
What "a component" does?? - you must specify that..
The problem with decoupling fast logic is stray inductance between the chip
and the decoupling cap - small caps near the chip win because of this. Any
capacitor technology that's not wound will work (winding produces inductance).
Many electrolytics are wound.
I see... it sounds like a capacitor would definitely be needed. I will experiment with this to see what I find out. As for the "components" these include a GPS, and a HIH-6130 temp/hum sensor
