Is there any different using two power supply?

[phonemyatt]

Hi, Im new member and I like building robot.Now, I m building R/C controlled robot car and all the parts in it is mostly from my old helicopter. Now, the problem is I need two power sources to run the motor and my new mbed microcontroller. My old helicopter run with 3.7V battery which like most heli but I wan to supply 5V at least to my microcontroller. So, should i use two different power supply or should i just step down 5V to 3.7V, supply 5V to microcontroller and 3.7V to my heli motor. FYI, I m gonna connect motor to gear to control 2 rear wheels. What are the adv and disadv? I can't find the datasheet for my heli battery online(if someone wan know parts no.,feel free to ask). My mbed is on the way and i can start this exciting project in a few day. cheers.

 

[sparkyscott1]

Is weight a concern? If so adding second power supply may also be an issue. If 5V will handle load requirements I would think that step down would be the most cost effective and fastest way and would also keep weight load to a min.

 

[BobK]

Is there is particular reason why you must run the micro at 5V? Modern micros will run at 3.7V, in fact most of the newest ones will not run at 5V.

Bob

 

[CocaCola]

Is there is particular reason why you must run the micro at 5V? Modern micros will run at 3.7V, in fact most of the newest ones will not run at 5V.

He stated he was using an mbed, this is a full featured ARM breakout board that requires 4.5 - 9.0 Volts to operate...

 

[BobK]

Didn't realise "mbed microcontroller" was a specific term. Thought he just meant "embedded microcontroller"

Bob

 

[CocaCola]

Didn't realise "mbed microcontroller" was a specific term. Thought he just meant "embedded microcontroller.

Well like the other thread where you want to point out that I misinterpreted a post and make an issue of it welcome to the crowd of misinterpreting a post, a post that what was clear to me... See how easy that happens when a lot of details are not given, or when you make assumptions because they are not clear to you? Because lests be fair he/she did state "My mbed is on the way" not 'My embedded microcontroller is no the way'...

To the OP the mbed board has 3.3 Volt take offs, that should be enough to supply the 3.7 Volt electronics, or is at least where I would head initially...