If you’ve followed along so far, you already know that the robot electronics are all powered using a single 11.4-volt LiPo battery, mounted on the base unit. And you also know that the output of that battery is fed to a fuse block, which in turn has four outputs.
Now it’s time to see what happens to those outputs, or at least three of them.
Buck Converter Modules
The second level of the robot is built upon the top layer of the Wild Thumper chassis. It’s an aluminum plate that is supported using standoffs.
I switched the supplied standoffs to 50mm ones so that I could get a bit more space underneath for my batteries and motor wiring. And instead of regular M3 screws, I used knurled M3 screws, making removal of the plate much easier.
A lot of the second layer is occupied by the voltage regulators, three buck converters mounted in a long aluminum chassis. The chassis itself is actually formed using two extruded aluminum chassis units, joined at the center. All the chassis hardware was purchased from Amazon.
The three buck converters, again all purchased from Amazon, have the following specifications:
- 5-Volt output 1 – 10-amp variable output buck converter
- 5-Volt output 2 – 10-amp variable output buck converter
- 6-Volt output – 5-amp variable output buck converter
All of these buck converters have trim potentiometers that are used to see their output levels. I measured the outputs at the end of the connecting cables.
The three voltages, along with an unaltered 11.4-volt connection, are fed out of the voltage regulator chassis. No connectors are used for an improved connection, all connections are done on the other ends of the output cables.
Three connections are routed to the top chassis of the robot:
- 5-Volts for logic supply
- 6-Volts for servo motors
- 11.4-Volts for Pixhawk power supply and further routing
The other 5-Volt connection is wired to a 2.1mm power plug, to power the Nvidia Jetson Nano. The Nano has an external stereo camera and an SSD drive, as well as an internal fan and a WiFi card. So it requires its own regulator.
Here is a wiring diagram for the regulator section:
As these are all adjustable regulators, you’ll need to set their voltages correctly. Each regulator has an onboard potentiometer to make this adjustment.