rcaddict Posted November 16, 2019 Share Posted November 16, 2019 are thay worth installing - do they work link Quote Link to comment Share on other sites More sharing options...
Geoff S Posted November 16, 2019 Share Posted November 16, 2019 Probably not. That looks like an aluminium electrolytic capacitor. They are typical quite inductive because of the rolled construction of the etched alumimium plates (the etching increases the surface area and hence the capacitance). That means they have low resonanmt frequency even without adding a separate coil (the inductor) and so will change voltage quite slowly and not respond to sharp, high frequency glitches very well. They may help and probably won't do any harm. The best way to avoid brown outs is to fit a battery capable of sourcing easily the peak currents of your system. Personally I'm dubious of very high capacity (2AH) AA sized batteries because they have a high internal resistance and are more likely to result in low voltage troughs when you overload them temporarily. If you must fit an electrolytic capacitor then use a solid tantalum type. They typically have the same inductance as a lump of metal the same size (ie very low). I haven''t neded to buy any since I retired (over 20 years ago) but they were expensive then and probably are now. Better to use a decent battery in the first place. Geoff Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted November 16, 2019 Share Posted November 16, 2019 IMO, of no benefit and possibly making your set up less reliable by increasing the number of components that could develop a fault. On the subject of RX supplies I took some advice from a UK manufacturer of batteries, ESC's UBEC's and motors and used 3S2200 lipo and 20A UBEC on the basis of keeping it simple (using lipos I already had) and it was suggested that if a servo developed a fault/stalled then the UBEC would provide sufficient current to "burn it out" without dropping the voltage to the RX. I have a couple dual battery switches, but of course the switch is a common point of failure + both batteries' discharge at the same rate. Only advantage is if one battery cell goes open circuit, then the RX will be supported by the other battery. From experience cheap switches have caused the biggest issue and not ventilating ESC's sufficiently, oh and UBEC's that don't supply their rated current without "browning out" the RX Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 16, 2019 Share Posted November 16, 2019 Don't waste your time with capacitors. Get a properly specified battery or Ubec for your installation. No one size of battery will fit all and will depend on servo type. Please seek advice if you're not clear on how to check on your models servo power requirements. Not a straightforward exercise. Quote Link to comment Share on other sites More sharing options...
Stephen Smith 14 Posted November 17, 2019 Share Posted November 17, 2019 Posted by Chris Walby on 16/11/2019 21:46:59: On the subject of RX supplies I took some advice from a UK manufacturer of batteries, ESC's UBEC's and motors Really? Who's that, or are they a UK labellers? Quote Link to comment Share on other sites More sharing options...
gangster Posted November 17, 2019 Share Posted November 17, 2019 Nooo it’s papering over the cracks. Brownout is a technical word that some modellers have latched onto. I believe the technical definition really means poor installation or maintenance in terms of model flying. Get a decent switch harness and be prepared to change it frequently Also heed the words about batteries given above . For a normal sport model go with makers recommendation or if it’s big and fancy consider a back up system Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 17, 2019 Share Posted November 17, 2019 There are/were receivers which took a couple of seconds or more to re-establish a connection after a voltage dip on 4 cell packs or high IR NiMH packs which were subjected to high loads and I suspect that this popularised the brownout as a reason for having to break out the bin bags. I've certainly seen instances where models being flown on one popular system have suffered from this but fortunately my own radio still works on voltages where the servos have long since given up working when tested. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 17, 2019 Share Posted November 17, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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