Model Boat Mayhem

Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: funtimefrankie on April 24, 2007, 07:52:40 pm

Title: Battery elimination
Post by: funtimefrankie on April 24, 2007, 07:52:40 pm

My ESC doesn't have a BEC.
So are there any standalone ones available or can I use one of these L78S05CV from Maplins

http://www.maplin.co.uk/Search.aspx?criteria=L78S05CV&source=15&SD=Y

thanks
Frank

Title: Re: Battery elimination
Post by: malcolmfrary on April 25, 2007, 12:54:35 pm

The item you have found should be OK.  If you do a web search for the part number you will probably find a downloadable spec sheet for it (Maplins might have one hidden on their site).  Manufacturers somehow manage to print about 20 pages about something the size of a geen sheild stamp, but in amongst the dross is usually an application diagram.
The notes for the one you found claim a max input voltage of 35, and a max output current of 2 maps.  Treat this with caution - if you want 2 amps while losing 30 volts, thats a lot of watts to dissipate, and wouldneed water cooling.
Personally I would just go for a very ordinary 7805 regulator, capable of 1 amp, but if the supply voltage is ever going to be less than 7 volts the regulator will not behave.  Then you need a "low drop out" version.  If the supply is off a 6 volt SLA then you dont need a BEC, as modek electronics was designed to run off this type of supply.

Title: Re: Battery elimination
Post by: funtimefrankie on April 25, 2007, 01:11:12 pm

Thanks for the info. I'd be dropping from 12 volts, and I don't suppose I'd be near 2amps with a receiver, servo and esc

Title: Re: Battery elimination
Post by: HS93 (RIP) on April 25, 2007, 02:09:00 pm

try and keep the output wires as short as possible, we used them when  12th cars first started (before elec speed ctr) and they worked fine , we where using 7.2v what voltage are you using? and just out of interest what ctr are you using

Peter

Title: Re: Battery elimination
Post by: funtimefrankie on April 25, 2007, 04:35:32 pm

It's an Electonize 43X running on 12 volts

Title: Re: Battery elimination
Post by: HS93 (RIP) on April 25, 2007, 05:02:28 pm

If you get in touch with Electonize they will supply the components to up grade  , Or they will tell you what you need. Ill have a look if you want , its only a cap and reg  and a link , its a lot easyer than playing with external parts,  its the same board for both units I did one some time ago and it cost about £3 inc post from them.

Peter

Title: Re: Battery elimination
Post by: funtimefrankie on April 25, 2007, 05:48:42 pm

Sounds like a good idea.
I've had a delve into it and can see where you could fit a couple of components. I've also got one that has the BEC, but the board is a bit different. Ones got 43-1A printed on it,(without the BEC), the BEC one has 43-4A.
I'll get in touch with Electonize.