PilotAware
British Forum => Technical Support => Topic started by: EricC on September 18, 2016, 06:02:47 pm
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https://www.modmypi.com/electronics/power-and-batteries/hobbywing-5v-3a-ubec-step-down-converter.
Is this any use?
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That doesn't look like it has a USB output, so probably supposed to directly feed the 5v rail of the Pi so bypassing the incoming protection.
Due to the voltage drop caused by the Raspberry Pi, it is recommended to input a minimum of 6.5V to receive a stable 5V output. Anything lower than 6.5V will result in a low voltage warning on the Pi.
This I would treat as suspect personally, not least as the 5v rail is passed directly onto the USB ports and I've no idea what the voltage limits are for the various USB devices.
Be interesting to do some stabilisation and RF testing to see what these are actually like, a large ferrite on the output won't do all that much half way down the cable. And don't use one on a 28v aircraft.
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That unit comes from radio control modelling circles. They are used to power the 2.4Ghz receivers and servos and usually called UBEC or SBEC. I have seen them up-to 51V input and outputs around 12A.
No idea if they are fit for purpose, but I would not have thought them that bad if used for critical Radio links.
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I've just ordered this one.....The specs look good....even has a USB port built in.....will let you know my findings...
http://www.ebay.co.uk/itm/262489885410?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
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What I have used very successfully is a cigarette lighter socket
https://www.amazon.co.uk/Waterproof-Cigarette-Lighter-Socket-Charger/dp/B005LURIM2 (https://www.amazon.co.uk/Waterproof-Cigarette-Lighter-Socket-Charger/dp/B005LURIM2)
with an ANKER adapter
https://www.amazon.co.uk/Anker-Charger-PowerIQ-Technology-Motorola-Black/dp/B00VH84L5E/ref=pd_lpo_23_bs_lp_t_2?ie=UTF8&psc=1&refRID=P95BA2PD4PD5QZ060YKP (https://www.amazon.co.uk/Anker-Charger-PowerIQ-Technology-Motorola-Black/dp/B00VH84L5E/ref=pd_lpo_23_bs_lp_t_2?ie=UTF8&psc=1&refRID=P95BA2PD4PD5QZ060YKP)
This gets hidden behind the dash and forgotten. No noise whatsoever and excellent charging output
Keith
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I've just ordered the Anker, seems a much better unit.
Thanks for the onfo.
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I bought one of these...
http://www.ebay.co.uk/sch/sis.html?_nkw=Car+Charger+DC-DC+Converter+Module+12V+To+5V+3A+15W+with+Micro+USB+Output+Cable&_id=311320284184&&_trksid=p2057872.m2749.l2658
Cheap and it is rated to 3A so has capacity to spare - designed for wiring in but you could stick a lighter
plug on the end if you want to use a socket? The lead even has the correct plug on it for a PAW
Regards
Chris
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Anker arrived this morning, powered by
spare car battery. PAW live all day
no problems.
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I bought one of these...
http://www.ebay.co.uk/sch/sis.html?_nkw=Car+Charger+DC-DC+Converter+Module+12V+To+5V+3A+15W+with+Micro+USB+Output+Cable&_id=311320284184&&_trksid=p2057872.m2749.l2658
Cheap and it is rated to 3A so has capacity to spare - designed for wiring in but you could stick a lighter
plug on the end if you want to use a socket? The lead even has the correct plug on it for a PAW
Regards
Chris
Hi Chris.
When you have it installed in your aircraft can you let us know whether it interferes with your air band radio or not. This is the key to the effective use these inexpensive type of switched mode power supplies which can often be quite noisy.
Thanks
Keith
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Good point, I know what you mean - I will report back but it will be a while, I am adopting the 'power bank' battery pack approach for the time being...
Chris
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I may get a couple and see how robust they are, plus run some emissions tests on them. Being fully potted it will be difficult to see what is actually inside compared to what is claimed. The original link seems to be been removed, which "make" was this one as there are loads on there with various names and claims and it would be best to go for the same one?
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Yes, looks like the original supplier no longer has them (although I suspect they all come from the same production line!)
When I get home tonight I'll take a close up and post it - if you are able to run emission tests that would be very helpful, my logic was at £3.50 it was worth a punt...if it comes to it I could always post it to you to try out/evaluate?
This won't tell you that the next one you try will be the same of course, but if they are the same make perhaps?
Regards
Chris
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Yes, looks like the original supplier no longer has them (although I suspect they all come from the same production line!)
When I get home tonight I'll take a close up and post it - if you are able to run emission tests that would be very helpful, my logic was at £3.50 it was worth a punt...if it comes to it I could always post it to you to try out/evaluate?
This won't tell you that the next one you try will be the same of course, but if they are the same make perhaps?
Regards
Chris
I could test it, I am set-up for pre-compliance RF checks, although I wouldn't try and see how good it's protection is - generally when I try that I blow them up. A pic would be fine, I can always look to get something thats a close match.
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Here you go - looks like it's the same as all the others?
Regards
Chris
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Ta, I can get one with the same label on, thanks.
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Jeramy
Did you ever test the above? What are the results?
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Jeramy
Did you ever test the above? What are the results?
I ordered one, but as yet nothing arrived. I've just ordered another one - delivery is estimated at end of November. I've moved up from the £2.99 to the premium £3.65 version, I'm sure that will make all the difference 8)
I have been mulling a tweak to my 4 port chargers to also offer a 12v out, for those who have 28v aircraft and also want to use a.n.other 12v device - so only need the one supply for USB and 12v. Depends on what power output people would want at 12v.
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The 12v output sounds like a good idea. It would help if someone wanting to power FLARM Mouse or Redbox from a 28v aircraft.
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Hi Jeremy,
Following Richards train of thought....
From LXNav FlarmMouse Manual - LXNav FlarmMouse - 36 mA at 12 Volts, plus an extra 10mA at 12 Volts if using the standard LXNav external LED display.
From LX Navigation Red Box Manual - LX Navigation Red Box - ca. 60 mA at 12 volts, plus extra if using e.g. an LX Navigation external LED display. (LX Navigation recommends a 1 Amp fuse in the Red Box power lead at 12 volts, so presumably supply should be rated at least 1 Amp.)
I'm sure others will have plenty of alternative suggestions. Fortunately I'm on a 12 volt system (with a Charge 4).
Regards
Peter
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I have been mulling a tweak to my 4 port chargers to also offer a 12v out, for those who have 28v aircraft and also want to use a.n.other 12v device - so only need the one supply for USB and 12v. Depends on what power output people would want at 12v.
Yes please! The only real use I can think of is the FLARM, and it doesn't need much urge - even 100mA might be enough, but 250mA ought to be plenty. Could you add a 12V output on the Charge2 as well? We're just about to kick off a major panel upgrade on our (28V) share-o-plane and two Charge2s are in the drawings (one on the panel, and one in the rear). Deriving a 12V output for the FLARM mouse was one of the headaches remaining as we're rather tight for space, especially on the panel.
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I have been mulling a tweak to my 4 port chargers to also offer a 12v out, for those who have 28v aircraft and also want to use a.n.other 12v device - so only need the one supply for USB and 12v. Depends on what power output people would want at 12v.
Yes please! The only real use I can think of is the FLARM, and it doesn't need much urge - even 100mA might be enough, but 250mA ought to be plenty. Could you add a 12V output on the Charge2 as well? We're just about to kick off a major panel upgrade on our (28V) share-o-plane and two Charge2s are in the drawings (one on the panel, and one in the rear). Deriving a 12V output for the FLARM mouse was one of the headaches remaining as we're rather tight for space, especially on the panel.
It's a bit tight in a Charge2, but potentially possible, it's a reasonable form factor I think and I wouldn't really want to make it any bigger (although it would only be longer). I have to be careful about the costs involved, component prices have gone up 15%-20% over the last few months - my current stock of bits is running very low bought at pre-increase prices.
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I use one of these to run both my SD Nexus 7 and PAW:
https://www.amazon.co.uk/gp/product/B00OUK0N26/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
(https://www.amazon.co.uk/gp/product/B00OUK0N26/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1)
I cut the ciggy lighter plug off and wired it into a fuse on the RV's avionics bus. I have heard this in not recommended, but it seems to work fine.