12v to 5 v power supply

[EricC]

https://www.modmypi.com/electronics/power-and-batteries/hobbywing-5v-3a-ubec-step-down-converter.

Is this any use?

[JCurtis]

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.

[Ian Melville]

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.

[brinzlee]

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

[Keithvinning]

What I have used very successfully is a cigarette lighter socket

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

This gets hidden behind the dash and forgotten. No noise whatsoever and excellent charging output


Keith

[EricC]

I've just ordered the Anker, seems a much better unit.

Thanks for the onfo.

[Chris Parsons]

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

[EricC]

Anker arrived this morning, powered by
spare car battery.   PAW live all day
no problems. 

[Keithvinning]

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

[Chris Parsons]

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

[JCurtis]

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?

[Chris Parsons]

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

[JCurtis]

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.

[Chris Parsons]

Here you go - looks like it's the same as all the others?

Regards

Chris

[JCurtis]

Ta, I can get one with the same label on, thanks.