I am fiddling with a project: Glade air freshener with a wemos d1 so I can control it with Alexa. Currently its going from 120v house outlet -> 5v apple-usb adapter -> wemos d1 -> sparkfun power control board (using 3.3v power pin) -> Glade air freshener and it works as intended.
I noticed when testing and I had the onboard LED ON, the led dims when it activates, so I was like maybe make a circuit that uses a separate regulator that uses the 5v from the D1 that gets its power from the wall power supply and power the glade from the separate regulator. I found a eagle cad drawing of a d1 mini board and made a shield for it, took me a while but its on the way :).
I was about to place my order from mouser, I doubled checked the data sheet and realized I had the wrong type of capacitor in my cart, now I'm confused on which to choose.
The datasheet says
"a 10µF tantalum capacitor is recommended.
Aluminum electrolytic types of 50µF or greater can also be
used. A high-quality capacitor should be used to assure
that the ESR (Effective Series Resistance) is less than
0.5Ω
Data sheet:
the questions:
I was looking at using the 1206 package size (smallest I figure I can solder) and the tantalum with ESR that is in the .5 ohm range is 16v
Why would one choose 6v , 6.3v, 10v or even 16v for a project that will be regulated to 3.3v output with a 5v input?
Would a 16v rated capacitor work in a 5v to 3.3v circuit. I am still trying to understand hardware selection and understanding their datasheets and its tough, like need to go to school for this stuff
"A high-quality capacitor should be used to assure
that the ESR (Effective Series Resistance) is less than
0.5Ω"
What should one expect (operation wise of the 3.3v regulator circuit) if the ESR is too high or too low?
From some searching, if these capacitors are soldered backwards, they will explode easy enough to get right before soldering, but values and ratings is what I need help understanding
How much current is taking the glade air freshener? probably is a good idea to power it separately. Make sure that the USB adapter can provide enough power for all.
Regarding the capacitor, I'm not an expert, but I think that an SMD ceramic capacitor of 22µF at the input and output should be ok.
Ceramic capacitors in general have lower ESR than electrolytics or tantalum, but in the past were not so common for relative high capacities.
Low ESR is better (in general), with less internal resistance they charge and discharge faster, so they react faster.
And the maximum voltage for these smd capacitors usually is 10V or 16V, what is ok.
You can google for schematics of ESP8266 or ESP32 boards. Many of them have the AMS1117 regulator, and usually they put one or more ceramic capacitor at each side.
When you find the capacitor you need, use two of them in parallel. This setup will last longer and provide a lower ESR (Equivalent Series Resistance). It’s a trick I’ve used for years in automotive applications—if one capacitor fails, the unit keeps working, and the customer doesn’t experience any issues and no warranty recalls.
I finally got the pcb from jclpcb For the first board I just soldered on the hexfet and 10k resistor (like from the sparkfun powercontrol) and made the solder jumper I added to power the project from the 3.3v D1 regulator and It worked as it did before but nice and compact! (same led dimming/turning off/ and back on during air freshener activation).
I ordered everything from mouser , including the tantalum capacitors of the 10uf rating per data sheet. Interesting they have a humidity constraint... packaging had desiccant, and a moisture? indicating card and label that said to use within 168 hours after opening sealed packaging. Another note said to look up instructions on how to bake them to get rid of the moisture... interesting!!
I wound up buying both 10v and 16v just incase. Board #2 was populated with the TI reg1117 regulator, 2 of the 10uf 10v cap's and it worked! these SMD are crazy small for my Weller 40 watt soldering iron and skills but it all soldered in and noting went poof
easy enough to get right before soldering, but values and ratings is what I need help understanding
