Path: ...!2.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Jeroen Belleman Newsgroups: sci.electronics.design Subject: Re: Solar powered electrostatic motor drone ?? Date: Fri, 19 Jul 2024 00:42:05 +0200 Organization: A noiseless patient Spider Lines: 74 Message-ID: References: <1qwwjrq.1j72zdkfee00kN%liz@poppyrecords.invalid.invalid> <86oi9j9sojojf8qinhranoclb3mpoaj5ag@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 19 Jul 2024 00:39:34 +0200 (CEST) Injection-Info: dont-email.me; posting-host="458d03b24616e37ea8cdac84916ddbb9"; logging-data="2757489"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/+RIlqxPXOxNxi/3j0V2hy" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Cancel-Lock: sha1:s8cfIx9pqjmDFlkLS61HZhCrj18= In-Reply-To: Content-Language: en-US Bytes: 3997 On 7/18/24 23:59, john larkin wrote: > On Thu, 18 Jul 2024 21:49:14 -0000 (UTC), Phil Hobbs > wrote: > >> john larkin wrote: >>> On Thu, 18 Jul 2024 19:21:23 +0200, Jeroen Belleman >>> wrote: >>> >>>> On 7/18/24 18:42, Liz Tuddenham wrote: >>>>> Jeroen Belleman wrote: >>>>> >>>>>> On 7/18/24 07:46, Jan Panteltje wrote: >>>>>>> Researchers build ultralight drone that flies with onboard solar Bizarre >>>>>>> design uses a solar-powered motor that's optimized for weight. >>>>>>> https://arstechnica.com/science/2024/07/researchers-build-ultralight-dro >>>>>>> ne-that-flies-with-onboard-solar/ >>>>>>> >>>>>>> Well, ehh, unlimited flight time if any sun.. >>>>>>> Looks funny. >>>>>>> 4.5V to 9 kV power converter... >>>>>> >>>>>> I wonder if electrostatic motors would have been as practical >>>>>> as electromagnetic motors if the history of motor design had >>>>>> taken a different turn a century or two ago. >>>>> >>>>> I think Philips dabbled with them many decades ago. A report will be >>>>> somewhere in the Philips Technical Review. >>>>> >>>>> >>>> >>>> Thanks for that hint. The Philips Technical Review is a treasure >>>> trove of interesting stuff. >>>> >>>> I found a paper by B. Boll¥ on electrostatic motors: >>>> . >>>> >>>> Jeroen Belleman >>>> >>> >>> I wonder how many orders of magnitude an electrostatic motor is worse >>> than a magnetic motor, in some criterion like power per volume or >>> power per dollar. 6 maybe? >>> >>> >> >> The main problem for outdoor use is going to be leakage, I expect. >> >> Could be useful if you forget where you parked your car at the airport. ;) >> >> Cheers >> >> Phil Hobbs > > Seems to me that an electrostatic motor will need switching of many > kilovolts into the electrodes. Charging and discharging, efficiently. > > https://www.c-motive.com/ > > That alone seems messy to me. > > I was thinking of stacks of many stator disks with conductive sectors, interleaved with as many rotor disks. Running voltage would be a few hundred volts, maybe up to a kV. Commutation can be mechanical or electronic. If fed with AC, commutation is implicit, but some tricks would be needed to create a starting torque. Leakage in humid condition can be dealt with by covering the disks with an insulating coating. The problem is not so different from magnetic motors. Jeroen Belleman