Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Radio control receiver voltage not same as max motor voltage

Status
Not open for further replies.

obrien136

Junior Member level 2
Joined
May 27, 2014
Messages
24
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
174
I have a receiver for an RC car that has a 6V max voltage and the motor has a 9V max voltage. BY that I mean, the max supply voltage you can apply to the receiver is 6VDC, while the motor takes a 9V max input drive voltage. I don't get enough torque out of the motor with a 6V drive input so I was wondering if I cam use different voltages for the receiver and the motor controller as shown in the attached drawing.

George

controller-receiver.png
 

You can use two separate power supplies with a common ground. Or you can derive the lower (6V) voltage for the receiver from the higher (9V) source by a voltage regulator. This regulator also reduces a possible motor interference which may affect the receiver.
 

@obrien136

Most motor controllers have the motor power connected directly to them. Receiver power is often provided by that controller by what is called a BEC (battery eliminator circuit). The BEC is a voltage regulator to reduce motor drive voltage to whatever voltage is needed for the receiver. Here is how I would re-draw your circuit to include the BEC concept. New connections are in BLUE.



Every motor controller I have seen can be divided into a signal or logic section and a motor control section. The motor control section operates at whatever voltage is being used. Today, those voltages can be quite high relative to the typical logic signal of +5V. One could certainly design a signal section that would operate at those higher voltages (as implied in your drawing), but then consider whether the 5-V signal from the receiver would be detected as a positive (asserted) logic signal? Assume for that question you are using 48 V for the motor supply. Now, with your 9-V supply, I don't think that would be a problem. So, as suggested just above, you could get by with a separate lower voltage supply for the receiver.

However, unless there is a reason not to use a BEC-type circuit, I would concur with the suggestion by jiripolivka and use a voltage regulator to provide power for both the logic of the motor controller and the receiver.

John
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top