Nick Cripps Posted November 12, 2023 Author Share Posted November 12, 2023 Questions 16 to 19 are straightforward and you either know them or not so not much to discuss there. Here's an explanation for Q20 for those who may want it. The nominal capacity of a battery is defined as the current to discharge the battery in one hour. This applies to all batteries regardless of their voltage, 'C' rating or even chemistry so the only information you need to look at in the question is the capacity (2200mAh) and the current (11A). For some unknown reason all model aircraft batteries are quoted in milliAmp-hours (mAh) which we first convert to Amp-hours by dividing by 1000 to give the capacity a 2.2Ah so that we have consistent units for the calculation. So if the battery can give 2.2A for one hour and we are discharging it at 5 times that rate (11/2.2) then it will last for 1/5 of an hour or 12 minutes. This is theoretical of course as you would never normally completely discharge a battery (especially a Lipo) and, in the real world, the capacity of a battery is dependent upon the rate of current it is being discharged at - the higher the current, the lower the available capacity. Hint for Jon: the formula is given in the units 😉 Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 12, 2023 Author Share Posted November 12, 2023 Moving on, we finish off with the traditional picture round: 21. 22. 23. 24. 25. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted November 12, 2023 Share Posted November 12, 2023 5 out of 5 on that one! Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 12, 2023 Share Posted November 12, 2023 Ditto but I’ll admit to having to check my “informed guess” for 24. Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted November 12, 2023 Share Posted November 12, 2023 4 out of 5 - don't know second one... Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 12, 2023 Share Posted November 12, 2023 3.....4/5 Wrong age (16) 4......4/5 No idea of the aeros designation. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 12, 2023 Share Posted November 12, 2023 1 minute ago, Cuban8 said: 3.....4/5 Wrong age (16) 4......4/5 No idea of the aeros designation. Reckon 5/5 on 5. Quote Link to comment Share on other sites More sharing options...
J D 8 Posted November 12, 2023 Share Posted November 12, 2023 Got the lot [I hope] Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 12, 2023 Share Posted November 12, 2023 (edited) The battery ratings given as mA hours for modelling use is probably just an historical thing where in the dim and distant past, batteries for model flight use would need to be physically tiny and accordingly, with only a fraction of a full Amp Hour capacity. Either that, or a large lightweight model that could carry the battery weight for valve receivers. When I started in the early/mid seventies, the normal size would be the four cell AA nicad of 0.5 A/hr or labelled 500mA/Ahr. All transistorised gear so nowhere near the current draw of older technology. Rechargeable batteries for other domestic uses didn't have quite the physical size or weight constraints - e.g. wet cells for early wireless sets - car and motorbike batteries etc so |Amp Hours figures would have made more sense. Bit before my time but the old DEACS button cells that I've read about in the history books 😉 were even smaller. DEAC was, I believe, a trade name for a brand of cells that comprised all sorts of types and sizes not just model batteries. I'm sure I recall DEACS still being advertised well into the 70s in the model mags. Edited November 12, 2023 by Cuban8 Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 12, 2023 Author Share Posted November 12, 2023 That makes sense, C8. I flew control-line in the mid-to-late '70s but some of my friends dabbled with racing 1/12th scale electric cars and they used DEAC packs. At the time, the 6-cell Nicad pack was charged from a 12V battery via a resistor, switching it off manually after the appropriate charge period. When one of them found his DEAC pack low at low voltage one day, he connected it up to his charger for a quick top-up but then forgot about it while he went off to get a drink. Some minutes later there was a loud pop as his DEAC overheated and burst open! A quick search shows that DEAC is a trade name - Deutsche Edison-Akkumulatoren-Company GMBH. Quote Link to comment Share on other sites More sharing options...
Jon H Posted November 12, 2023 Share Posted November 12, 2023 6 hours ago, Nick Cripps said: Hint for Jon: the formula is given in the units i came at it another way but ended up with the same result. 2.2/11 x 60 was the formula i was trying to remember. in any event, 5/5 for me on that one and i think 5/5 for the new set too 1 Quote Link to comment Share on other sites More sharing options...
Jason Channing Posted November 12, 2023 Share Posted November 12, 2023 (edited) On 11/11/2023 at 09:47, Engine Doctor said: Fruit cake with mazipan for me thanks😀 Seriously though looking at most drivers today passing a theory test is forgotten the moment they are given their pass. A bit like schooling these days , students are rauught to pass the exam and not any indepth knowledge of the subject . Learn it parrot fashion and pass . I think ive got them all correct this time , possibly maybe 🤔. That's how Airline pilots pass the theory these days, question banks galore with no real understanding of the manuals, My sons a licensed aircraft engineer and that's a different story. Edited November 12, 2023 by Jason Channing Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 13, 2023 Author Share Posted November 13, 2023 Time for the answers to the picture round. How did you do? 21. Wot 4 22. Tomboy 23. Riot 24. Crescent Bullet 25. Panic Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 13, 2023 Author Share Posted November 13, 2023 That's it, all done, hope you enjoyed it. Anyone get 25/25? Feel free to use any of these for your own club quiz night - I'm sure you can think of plenty more to add if you do. 4 1 Quote Link to comment Share on other sites More sharing options...
Phil Green Posted November 13, 2023 Share Posted November 13, 2023 Thanks Nick, this has been a fun topic when theres not much flying 😁 1 1 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 13, 2023 Share Posted November 13, 2023 4/5......couldn't recall the Crescent Bullet. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 13, 2023 Share Posted November 13, 2023 On 12/11/2023 at 13:32, Nick Cripps said: That makes sense, C8. I flew control-line in the mid-to-late '70s but some of my friends dabbled with racing 1/12th scale electric cars and they used DEAC packs. At the time, the 6-cell Nicad pack was charged from a 12V battery via a resistor, switching it off manually after the appropriate charge period. When one of them found his DEAC pack low at low voltage one day, he connected it up to his charger for a quick top-up but then forgot about it while he went off to get a drink. Some minutes later there was a loud pop as his DEAC overheated and burst open! A quick search shows that DEAC is a trade name - Deutsche Edison-Akkumulatoren-Company GMBH. Didn't know that old rascal Edison was originally involved with the company.......... Quote Link to comment Share on other sites More sharing options...
J D 8 Posted November 13, 2023 Share Posted November 13, 2023 Sadly only got 3, thought bullet was a gangster and tomboy a ballerina. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted November 13, 2023 Share Posted November 13, 2023 I got the Panic, I’ve had quite a few. I also thought the Wot 4 was a UnoWot, had a few Wot 4 s too. Downhill from there. Mutter, mutter. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted November 13, 2023 Share Posted November 13, 2023 Almost forgot! cox, fleet, film, king, bus, cloud, pin, hour, top, smoke On 11/11/2023 at 21:34, Phil Green said: Heres an easy two-minute between-rounds thing, middle word? brian --- 049 digi ----- air arm solar ---- star hobby ---- charles air --- stop lenticular ----- nine gudgeon --- point amp ---- glass spinning --- gun magic ----- signals 1 Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 13, 2023 Author Share Posted November 13, 2023 I thought the last one was radio Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted November 13, 2023 Share Posted November 13, 2023 Seems to work with either smoke or radio. Quote Link to comment Share on other sites More sharing options...
Nick Cripps Posted November 13, 2023 Author Share Posted November 13, 2023 It does! I'll claim 100% then. Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted November 13, 2023 Share Posted November 13, 2023 Missed the Tomboy and on Phil's Quiz missed the Amp Hour Glass connection too. Shameful on both counts. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 13, 2023 Share Posted November 13, 2023 What's Magic radio - was it a brand I've missed...or something else? 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.