Experiments with Super Capacitors for IoT Projects
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Random testing of super capacitors - was running these tests on the bench and thought a video might be interesting? The project I'm planning for this is going to be really cool and will make a video on that soon.
The 2.5F capacitor I'm using: DGH255Q5R5
The google sheet project docs: trigboard-docs...
Constant Current Regulator is a ZKE EBD-A20H
Power Supply is an Otii Arc
Tindie link to trigBoard: www.tindie.com...
Thanks to all the Patrons for dropping a few bucks in the tip jar to help make these videos happen!
/ kdarrah
Twitter: / kdcircuits
For inquiries or design services:
www.kdcircuits...
Very nice video. I like your low power projects, thanks for sharing :)
What about leakage current of the capacitor itself. Can it stay charged enough for days or at least one long night?
great stuff. great explanation of ESR!
Power provision to these IoT devices is a big problem. No-one wants to be changing batteries all the time and you can't get a fixed power run to all the places where they would be useful. If you could do something viable with indoor solar and a supercap it would open up so many possibilities!
Super cool stuff here. I'm glad Dave (over at EEVBlog) gave you a shout-out during Mailbag recently... I think I'm going to like this channel. :)
In particular, I've been thinking of doing indoor solar harvesting with supercaps for occasional updates on electrophoretic (eInk) displays, etc., so... I'm glad to see I'm not alone in exploring this space! Alas, my EE knowledge isn't what I'd like it to be, so I've been putting it off as I work on other things that are easier for me (I want to avoid back-feeding the solar panels, but also don't want to lose a bunch of voltage to a separate diode, and..... beyond that, I have ideas, but I don't yet know if they'll work). Anyway, I look forward to seeing what you come up with!
Thanks a lot for this video! It is a super interesting concept :-) Look forward to giving it a try. Could the light panels also be used for outdoor projects?
Can Supercapicitors charge via a Solar Panel/Hand Crank while it's being used and discharging?
yes, my continued testing is showing very good results - also designed a board for a part 2 to this
@@Kevindarrah Thank you, I'm looking at using a dc motor driven by a vawt to charge the caps via a charge controller, then using an inverter run a heater so when it's windy I'll be toasty! Sounds simple but I bet it probably isn't!
Hello. Can you please tell me the brand and model of the oscilloscopes you're using? thanks
Otii Arc - the plotting is built into the software
What if you pair up a cheap supercap with let's say a 470uf low ESR cap, that can't store much but can deliver a lot of current for those wi-fi transmissions, and charge gradually over time as the high ESR of the supercap allows? I think that should work.
Where can you buy such a flexible solar panel? I have flexible ones with a thin steel sheet backing, which makes them quite heavy. I'm looking for lighter ones like yours, where can I buy one?
Can you please make a video on " How to convert an old DVD ROM of PC into a independent DVD player with additional USB media input ". ?? It would be great as there is no such video on youtube regarding this topic.
Good stuff, wonder how much more the 5V would give?
yea I was curious as well - 27 wakes logged to the sheet!
I just want to make a usb powered board that holds its power for a few seconds when usb power is lost.. I cant figure it out.. high esr makes inrush current perfect for usb, but the esp32 fails because of peaks shown in your video. Low esr shorts the usb, using a resistor makes the voltage drop too much, a diode too.
dont tell anyone, you are clearly the best on youtube. Thanks for your content!
thanks!
I'm happy to see others share my interest! I've been working on similar projects, exploring ways to utilize capacitors in a more battery-like fashion. While they're fundamentally different components, I've achieved some promising results.
In fact, I developed a formula for this purpose when I was just 14 years old. I understand it might be controversial, but I urge you not to be discouraged by the math in the video description. The video itself might not be for everyone, but the underlying mathematics is sound.
Here's the idea: Why not take a look at the equations I present? If they align with your understanding, perhaps they could be helpful for your capacitor project as well!
th-cam.com/video/Q7EmfHowWkU/w-d-xo.htmlsi=nv0cwxwRTZmoLwz0
Will the trig board charge this super capacitor? Can we replace the battery with this super capacitor?
How long would last that coin capacitor as laptop cmos bios replacement?
Isn't 4V too much for the ESP32?
To my knowledge from what I've seen online you're gonna have to de-rate all those super capacitors a lot because none of them do actually have the capacitance that they are rated for, measuring super capacitors accurately is also a problem since most meters aren't designed to measure super capacitors.
If you have the means to measure your super capacitors you'd quickly find out that all those super capacitors don't even come near to the rated specs.
yep - mentioned in the video an experiment I was doing trying to measure the time constant to figure out capacitance... reason I used 10W resistor was to keep temps regulated on the "R" while charge/discharge. But funny thing was that capacitance was soooo off on that cheapy that I thought something was wrong with my setup!
For comparison.. How many wakes would you get with your Li-Po battery??
1000's
This is super interesting, thanks! I have some ideas for these kind of supercapacitor. I see they're available at 500F, which should be plenty for any application that wakes up from time to time. Add a small solar panel and you can probably get back most of the energy you consume in the pauses
Yes! Just what I was looking for. My greenhouse will have x number of sensors that will log data via WiFi. I wonder if I can charge the cap using RF harvesting of the same WiFi it uses for Tx?
Best show of ESR I've seen yet. I could see this being exceptionally useful for an outdoor sensor in an awkward/hard-to-reach area. Another TH-camr, Julian Ilett, is aiming to build a bluetooth speaker powered by giant scary huge supercaps (mostly for the cycle life).
Maybe I'll make a quick video showing you these experiment
Thank you Kevin ;)
This may be a bit too straight-forward, but what about hooking up a small generator to the door itself? Maybe even integrate everything into a small, self-contained unit that you can just glue or fasten to the door :)
Dave sends his regards! ;)
Epic video thanks!
solar with a supercap - love it for external wireless home security or post/mail notifications
How about two caps in parallel
10:57 Let's see what happens, were gonna start it. //bad cut// so this is exactly what I wanted to show you.
What ????
Great video to understand the impact of using a proper capacitor. Would love to see more of your experimental videos such as this!
Thanks, Kevin. Good stuff
Awesome
You should really try out Lithium-ion capacitors, basically a hybrid between supercaps and lithium batteries. Supercaps are usually horrible for IOT projects because the leakage is so high... but with LIC's its
cool - yes I need to check these out, thanks for the tip!
I actually use supercaps as backup batteries for my projects, the biggest issue is to manage power surges toward the supercap.
these are just two supercaps in series. you had to care for a kind of balancing or one of them will be dead soon.
This is a super interesting concept. Especially with the indoor energy harvesting idea. Powering IoT devices with the use of energy from light and heat. Would love to see you attempt using body heat to fill upp that super cap.
Hey! I’ve been looking for that esd mat forever. Do remember where it came from?
Great video , Keep up the good work. i am sharing this among my friends
Great video!
This is awesome video and pretty helpful. Actually I am working on a project whose one aspect is to send "phase missing" status to my databases when power goes off. I need 4 sec to 5 sec backup for esp32 and calculated nearly 0.7 F capacitor but I am planning to use 1.0F capacitor (cheap version 😊). I am concerned that will it work? As you showed that it did not work in your case.
By the way, I like the flow of your videos. Awesome content!
thanks! well it's easy enough to test, but I have a very similar idea as well to detect power outage. Might make a video on that
Hello Kevin, good job, as always wonderful content. I am worrying about how to charge those SC, as you said, there must be a resistor in series with it in order to control the peak current. If I use a solar panel as a charging source, the resistor would be in function of the max power of the solar panel. So, selecting a small solar panel (~1W/6V), the resistor would be high and there is gonna be a voltage drop in it that is not power efficient.
yep, I've got some cheap Ebay dev boards coming... will make a vid on how that all goes
This was very interesting (and useful). How does cold affect the supercaps? I believe you are in a good area to test this... if this was sitting outside around the freezing point, how would it affect the number of notifications?
I believe they perform better than lithium in cold temps - and yes you're right, I'm in the right climate for this. Going to rig up the mailbox to be supercap only
Interesting as always
Thanks for sharing :-)
Thanks Kevin keep up the good work and great to see your research on this! Any kinetic energy harvesting tests planed for remote trigs (wind/water/thermal where solar may not be viable)?
yea, was thinking about that. Gonna start with solar and take it from there.
Great experiment. Thanks for sharing.
You *really* ought to look into CapXX (now-a-days "Murata") super-caps. These have a great tradeoff between ESR and self-discharge.
"Sanyo " style caps --> low discharge but high ESR.
"Maxwell" --> UltraLow ESR, high self-discharge
CapXX/Murata --> moderate/low ESR, pretty low self-discharge
oh cool, thanks for this!
Very cool, I have a bank of supercaps from an ambulance cardiac machine and it has a very cool board on it that only delivers the necessary voltage/current. Has even maintained its charge sitting in my battery drawer for over 2 months. It won't even burn out an LED when charged to about 16volts. Even almost dead it has run a 4 leg piranha LED for over two weeks. I have a few small solar panels that would keep it charged. Looking for the perfect project for it.
cool, yea stay tuned - planning on doing a lot with solar in the future
@@Kevindarrah very cool, I will be sure to watch
Would no LED help?
Compared to the current draw from the chip itself, probably still won't allow the Trigboard to send once on the 1F cap...
yep, ESP32 current dominates while on
Kevin, I'm really intrigued!
Excellent 👍🏻
Good testing.
This is an off topic question but are you using both windows and mac? I could notice halfway through the video a windows desktop. Unless you're using a virtual machine.
By the way, where did you get all that setup for plotting graphs?
yea, that ZKE software was windows only, so just runs in parallels. 3 finger swipe slides between windows 10 and macOS