Jim Stevenson Posted October 19, 2014 Author Share Posted October 19, 2014 Peter, our posts crossed. But take a bow for the info. I like the supercap idea simply for the weight savings and automatic run time limiter. Same ideas the cheap cells really. I have no fixed ideas of how to do this so all ideas welcome. I would even look at beamed power, no battery just a car sized generator and transmitter, but I suspect that could be a way off yet. Keep posting, I can keep learning. Jim Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted October 19, 2014 Share Posted October 19, 2014 I would think a test bed lash up would be a good way of approaching this, get a capacitor with a big capacity, and a DC Brushed Motor (I would think for a "proof of concept" a dirt cheap one would suffice) - charge up the Cap and hook up the motor - and lets find out the results.... for me this is totally unknown territory, but the electrical theory would seem to work, and there is a US Patent issued for a "toy aeroplane powered by a capacitor" Here - **LINK** - what I/we don't know is how practical it will be for your application Edited By Dave Hopkin on 19/10/2014 16:09:36 Quote Link to comment Share on other sites More sharing options...
Jim Stevenson Posted October 19, 2014 Author Share Posted October 19, 2014 Dave, This is something I along the lines of what I have in mind. It will need more research but it's a valid learning process. I might have to resort to a battery but we'll never know till I try. However getting the bits together may well take a while so be patient. Regards Jim Quote Link to comment Share on other sites More sharing options...
John Privett Posted October 19, 2014 Share Posted October 19, 2014 Posted by John Privett on 17/10/2014 20:54:50: One of the members of my club is a free-flight flyer and specialises in small ducted-fan models. His latest is electric and employs a small controller that does the job an ESC would normally do - so they are available. .... I don't remember all the details. I also don't know where he got the controller from, I can ask if you want? Just had a reply back from him - it was one of Derek Knight's (mentioned earlier in the thread) units when Derek was trading as Knight & Pridham. Derek is still trading by himself, selling edfs, flight controllers and other associated FF goods. Quote Link to comment Share on other sites More sharing options...
Jim Stevenson Posted October 20, 2014 Author Share Posted October 20, 2014 Hi John. I assume that it's forum policy that the forum is not used as a sales platform but if, as I am doing in this case, one member requests that either a third party (Derek Knight) makes contact with me regarding his merchandise, or that someone supplies a contact for the third party to enable the forum member to complete a project, will this break the rules? That was a big lump of legal jargon. Did it work? Regards Jim Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted October 20, 2014 Share Posted October 20, 2014 Jim, go part way down this page I think the F515. KP Free Flight Electric Control is what you are looking for, but drop them an e-mail I'm sure they can help. Quote Link to comment Share on other sites More sharing options...
Jim Stevenson Posted October 20, 2014 Author Share Posted October 20, 2014 Hi Frank. Thanks for the info, this will go in my bookmarks for future use. Unfortunately it contains the line: "Combine this tiny 1.3gm device with an electric speed controller" so although it will be useful for other things I still need an ESC. Luckily my motor is from eFlight so there is a matching ESC available "off the shelf". I might still need this to allow me to connect a capacitor instead of a battery. Regards Jim Quote Link to comment Share on other sites More sharing options...
onetenor Posted May 2, 2015 Share Posted May 2, 2015 How can a capacitor supply continious current ? Quote Link to comment Share on other sites More sharing options...
AJ Posted May 2, 2015 Share Posted May 2, 2015 Any cap will store a charge which can then be drawn as required. A super capacitor does the same thing but stores a far larger charge and has low leakage so it can hold the charge for some time. The big benefit is that it can be charged far more rapidly than a chemical battery. A. Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted May 2, 2015 Share Posted May 2, 2015 Posted by onetenor on 02/05/2015 16:46:40: How can a capacitor supply continious current ? In the US Patent (linked above) I am GUESSING the Charger unit is used to charge up a very large the Capacitor, which when discharged across a DC brushed motor will supply sufficient voltage to drive the motor - the motor run duration would be dependent on the capacity of the capacitor and the resistance built into the motor circuit to limit current flow - in this application the capacitor is acting in a way that effectively becomes the on-board "battery" So yes it could, how practical it would be is another matter..... a like "pop pop" engines, they work in theory and on a very small scale, but not when you try to scale the up Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 9, 2022 Share Posted May 9, 2022 (edited) The Peterborough club members are champions of supercap flight, I think the main problem is the low voltage, only a rapidly-declining 2.7v peak per 'cell' and of course two in series for 5.4v gives half the capacitance, 4S/10.8v would be a quarter etc. The exponential voltage drop can be corrected to a degree with a PWM controller but again, to flatten the curve, through the run it will average around half the peak voltage, and of course the controller itself needs a working minimum voltage, so might only be worthwhile for upwards of 2S. For ease maybe direct drive with no electronics and treat it like a simple rubber-power model (similar declining power curve)? Cheers Phil Edited May 9, 2022 by Phil Green Spelling :-( Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 9, 2022 Share Posted May 9, 2022 (edited) EDIT: Sorry I just realised how old this thread is! Not sure why it popped up..... my mistook ? Eg this one has a single 3F supercap: https://www.amazon.co.uk/Capacitor-Electric-Throwing-Free-flying-Airplane/dp/B079J6QTVY Edited May 9, 2022 by Phil Green Quote Link to comment Share on other sites More sharing options...
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