and can see its working nicely with a simple 6 volts battery..with 4 standard servos and 4 HD servos..

the sum result is satisfying but the device was heating up...

and with 12 volts..
i told you..the device was heating up as it alone drives the HD servos..so, all we know it is not feasible to leave a power device to its limit..still nothing wrong is happened because the device is protected from over heating..
so i added an even more versatile configuration..as a Darlington pair...with T I P 3055..

we do not need to add any diodes in between pin 2 and ground, but can add an L E D, between these two leads, also acts as a power indicator..so you can see the output voltage stepped up to 6 volts..
but i request to you all, that if you are working with cheaper quality servos, it is advicible to go with 4.5 volts..because i have many bad experiences with cheap servos, as i tried to add some loads with 5 volts..and make sure your servos are good in H bridge circuits..

and with DP config this unit became more versatile..no input loss..(negligible), no over heating..and driving HDs a lots..still working on real crafts..test continues..

Friends..will share some B E C circuits that employs some complex components..research a lots yourselves..in your model making..and we will sucseed at will..imagine our craft completed with own ideas...its unimaginably satisfying...inspiration never ends..it will continue..on..and on...and on...

see some experiments here..with BEC..

once again..research yourself a lots..make your crafts even better..yes..not with complicated ideas..but through simple ideas...we must leave the ignorance behind us..and must study ourselves..wish you all a happy prosperous new year..with loads of nice crafts...

KIA 78D05 is the low drop out 5 volt regulator unlike LM7805 or simply 7805 But similar to LM2940CT-5
Datasheet is here.

Consult A. P. Malvino's 3rd Edition of "Electronic Principals" for any type of design. The simplest design book I have ever seen with Rock Solid Backbone and fine tuning.

LED is equivalent with a series Zener with resistance. So loading or input voltage variation varies the current of LED and the voltage across LED changes as the equivalent resistance drop changes. So, it is always preferred either a voltage divider with output to ground and connect the center pin of fixed Zener voltage or Diode string (Similar to diode).

If you add 2 transistor in Darling Pair as buffer, then 1.4 volt drop at output occurs.
Red LED is equivalent to 1.6 volt zener with series resistance. To avoid voltage variation due to change of current in LED use 2 nos of 4007 or 4148.

But the simplest is using one zener, resistance and Pass Transistor. Insted of using vero board, use metal TAB heat sink.

The best one is switched mode BEC for higher battery voltage.

And the cheapest ESC for 2S is make 3S3P diode array (1N4007) and make series with positive voltage drop. You will get 7.4 - (3x.7) = 5.3 volt (theoritically)

but practically you get 6 volt. (guess why?) ----------- Home Task.
Consult any book except I recomend.

Try it.

Thank you Kalyan..and continuing my research, to make my BEC even better..and found we do not need any complicated circuits then as this circuit powered a big craft with two motors and 4 HD servos..and some switched BEC is making some interferrence especialy in an FPV and UAVs..still happy..DP configuration makes some drops in voltage, but gives a better stability..and if we want to alter the output voltage according to our needs we can add a even simpler device in between..no need of further book referings..but must find myself by research..once again..thank you Kalyan..inspiration continues..