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Topic: Sabertooth Dual 2x25 and Arduino power distribution board (Read 1 time) previous topic - next topic

dustinwloring1988

I'm trying to make a power distribution board that will have 3 outputs they are:

1) 24v for the Sabertooth Dual 2x25
2) Arduino Uno v3
3) 3.3v (optional use)

Hocked up to the Sabertooth are 2 electric scooter motors with the following specs

*Type: Brush Motor
*Voltage: 24V DC
*Current: 15.4 Amp
*Output: 280W
*Rotation: 2750 RPM
*Torque: 0.90 N-m

Hocked up to the Arduino is 2 gyro sensors, 1 accelerometer, 16x2 LCD, i2c real time clock w/battery backup, compass sensor, 2 (pressure sensors) Interlink Electronics 1.5" Square FSR

I'm also not sure what battery pack set up to use they cannot be Lead Acid batteries. So I had 2 options in mind they are:

Six 8.4v 5100mah NiMh battery packs hooked up two sets 3 in parallel then the 2 sets hooked up in series so that I get 25.2v 10200mah

Or

Four 12v 3800mah NiMh battery packs hooked up two sets 2 in parallel then the 2 sets hooked up in series so that I get 24v 7200mah

Thanks,
Dustin

Krodal

#1
Feb 04, 2013, 07:57 am Last Edit: Feb 04, 2013, 08:04 am by Krodal Reason: 1
For the Arduino you could use a DC-DC converter to about 7.5V and supply that to Vin.
Many DC-DC converters have an adjustable output, so you can set them to 7.5V.
The Arduino Uno supplies 3.3V (but not a lot of current) for sensors and so.

The Sabertooth motor driver contains already a DC-DC converter with 5V output. It is not recommended to connect that to the 5V pin of the Arduino (a lot discussion on the forum about that), but some say it should be no problem.

I think you can't make a regulated 24V power supply. Just use the battery output to the Sabertooth motor driver. You have to add a fuse for current protection, and perhaps a shutdown relay.

Do you have more specs for the motors ?
Is the 15.4A the maximum current ?

Using batteries in series and parallel could be very dangerous. I would not stand next to it.
You might try a battery pack for an electrical bicycle. Some of them are 24V 15...20A.
They might cost a few hundred euros/dollars, but it is worth it, because of the safety issue.

dustinwloring1988

No that was all the specs I had on the motor it's used in the early model e300 scooter so I would hope that it is the normal running amps.
For the fuse Since the Sabertooth can handle 25amps per channel and the motors need 15amps would a 40amp fuse in between the power distribution board and the Sabertooth.
Here are some specs on the step down regulator


Pololu D24V6ALV Step-Down Voltage Regulator
Product code : RB-Pol-116
• Step-Down switching DC-DC converter
• Maximum output current: 600mA
• Input voltage: 4.5V to 42V
• Selectable output voltage: 2.5V to 7.5V
• Features under-voltage and short-circuit protection
Thanks for your help,
Dustin

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