Hi, All
I want to test the water and learn how much support is out there for a power management and distribution system for the APM 2.x. The APM 2.x is now a well understood and reliable FC. Maybe now it is time to design a stable and reliable power system for it?
There are far too many threads and comments in the forums regarding power issues. In most situations the APM is relying upon ESC bec's that were not designed for a UAV FC and there is much trial and error patching together bits and pieces of varying quality from different sources. None of the open source UAV projects has built an intelligent power management system for our UAVs yet.
I spent the last 2 days thinking about what in my opinion our APM 2.x's need. My idea is explained below. But, I want to hear your idea's and thoughts. That's the aim of this post.
My idea is a pcb that sits underneath APM 2.x. The signal pins A0-A11, signal pins for the PWM outputs and one of the UART ports from the APM are extend down into it and attach it to the APM 2.x. Headers on the PCB to attach devices to A0-A11 and Servo/PWM outputs. The pcb has 3 switching power supplies. One for the APM, one to power the PWM outputs and one to power FPV equipment or accessories. A AT2560MEGA processor to control routing of power, and monitor voltage and current. External pcb's that attach to each battery route power to the main pcb, monitor voltage and current, and can isolate the battery.
APM 2.x Power management and Distribution system (apm pmds) pcb
- ATMEGA2560 processor
- Monitor various voltages and currents
- control routing of power between batteries and power supplies
- isolate batteries and servo/PWM outputs
- isolate batteries and power supplies
- Communicate with APM 2.x
- Develop power management strategies
3 switching power supplies
1) apm ,pmds, sensors, rc receiver & rf modem
- 2 amp
- current sensor
- voltage sensor
- able to independently switch between batteries
2) A0-A11 and servo/PWM output
- 5 amp
- current sensor
- voltage sensor
- able to independently switch between batteries
- able to adjust power output for HV servos
- Opto-Isolators on the servo/PWM signal outputs
- Isolate the power via physical switch
- support for optional external capacitor array
3) fpv transmitter and camera or accessories
- 2 amp
- current sensor
- voltage sensor
- able to independently switch between batteries
- able to shutdown fpv transmitter/camera/accessories in a low power situations
Battery controller pcb's
- Isolate battery
- current sensor
- voltage sensor
- Monitor voltage in up to 4 cells
