Reduce voltage to a motor

[MichaelC]

Hi all,

How do you go about reducing the voltage of the motor output ? Thinking of using a Tk-35 board for a 1/35 project, and the gearbox that comes with the kit uses a single AA battery. I think I can safely use 3.0 volt, but6 volt from Clark Tk-35 might kill it ? Can't afford to burnt out the motor to test it out unfortunately.

Would a single inline resistor do it with the correct rating ?

MichaelC.

[AlwynTurner]

Hi, I had to reduce the voltage on some servos and I used a 22 ohm resistor in series, although you might want to start with a 47 ohm to start with so you don't blow the motor, and change it to a 22 ohm if it winds up too slow.

Alwyn

[tao]

These little $ 6-10 step downs are good for dropping voltage and are adjustable.

DROK® DC Step Down Variable Voltage Regulator 36V to 24V 12V 5V 3.3V 3V Buck Converter Electronic Volt Stabilizer Car Automatic Battery Adjustable Regulated Power Supply DIY Voltage Transformer Bare Module Board

[tao]

Though note..the voltage can't be reversed like with a turret motor.. so then a resistor or 3A 100v Diode Rectifier..I used those you can keep adding pairs to drop voltage.

[AlwynTurner]

Hi Michael you could also consider these mini-controllers, haven't used them but am thinking of putting one in my universal carrier
http://www.35rctank.com/html/p3.html
Alwyn

[MichaelC]

Thanks guys. This is more complicated than I thought. I will have to look into what the motors are rated at and see what I can do on the Tk-35 side.

[MichaelC]

I managed to get the output to abut 2.5v - 3.0v from almost 8 volt at 100% throttle by adjusting the radio. I have to make sure that I choose the right profile when I use it otherwise it will definitely kill everything, but it is good enough for now.

Interesting enough, when I just put a 100 Ohm resistor in line, I get a drop in voltage but the motor won't move. I guess it has something to do with the amp as well as mentioned.

MichaelC.

[AlwynTurner]

Hi Michael yes 100 ohm is far too much, try 47 ohm and then 20 ohm. It worked for me - I'm no electronics expert - I just experimented until I found what worked.
Alwyn

[tao]

If is just a voltage drop to a main power source lower those little voltage regulators are great. Great for stepping up
the voltage too (I like to run the TARR heat element at around 9 volts)

[BarryC]

Michael,

Ohm's Law is the solution to your question.

http://www.bcae1.com/ohmslaw.htm