# Signal Distribution Box
**URL:** https://dao.arrowair.com/t/signal-distribution-box/49
**Category:** Engineering
**Tags:** electrical
**Created:** [September 10, 2024, 1:11pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49 "2024-09-10T13:11:57Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Julius](https://dao.arrowair.com/u/Julius)
#### Post date: [September 10, 2024, 1:11pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/1 "2024-09-10T13:11:57Z")
**Functions of the Signal Distribution PCB**
- Integrate all components of the aircraft system
- Battery 1-6
- Flight Controller
- Cockpit
- Charger
- Parachute
- Companion Computer
- Flight Sticks
- Altimeter
- Magnetometer
- …
- Power distribution and redundancy circuit
- Signal distribution
- Easy wiring
**Changes in V2 compared to V1**
- Added an Arduino with can bus interface to enable the digital switching of the DCDC converters (for the power supply and also the ones to enable the individual batteries)
- 18650 battery cell with charge circuit to start the Arduino without a battery connected
- Connection to the toggle switch PCB is now digital over CAN
- Changed the type of connectors for better assembly
- The options to enable the batteries over CAN makes it possible to use the new charge PCB
Schematic:
2D Layer:
Link to the files:
[https://drive.google.com/drive/folders/1cy5KKfoVCfPxOt3CjgzBpIf\_tykwnJXx?usp=drive\_link](https://drive.google.com/drive/folders/1cy5KKfoVCfPxOt3CjgzBpIf_tykwnJXx?usp=drive_link)
---
### Author:  [@errrks.eth](https://dao.arrowair.com/u/errrks.eth)
#### Post date: [September 11, 2024, 4:23pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/2 "2024-09-11T16:23:04Z")
wow man what a tease
---
### Author:  [@Julius](https://dao.arrowair.com/u/Julius)
#### Post date: [September 16, 2024, 2:56pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/3 "2024-09-16T14:56:36Z")
- Connection to the toggle switch PCB is now digital over CAN
---
### Author:  [@errrks.eth](https://dao.arrowair.com/u/errrks.eth)
#### Post date: [September 17, 2024, 5:50pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/4 "2024-09-17T17:50:53Z")
> Connection to the toggle switch PCB is now digital over CAN
That’s a fantastic optimization.
---
### Author:  [@thomasg](https://dao.arrowair.com/u/thomasg)
#### Post date: [September 23, 2024, 2:22pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/5 "2024-09-23T14:22:38Z")
This is a really solid improvement, thanks Julius!
Is there any particular reason you went with an 18650 cell instead of a 21700?
---
### Author:  [@Julius](https://dao.arrowair.com/u/Julius)
#### Post date: [September 23, 2024, 2:50pm UTC](https://dao.arrowair.com/t/signal-distribution-box/49/6 "2024-09-23T14:50:20Z")
Glad you asked!
So i originally wanted to put in a LiFePo4 cell, because they are a little bit more safe and have a better cycle life. I looked at some suppliers and you can’t really buy 21700 LiFePo4 cells, most are 18650. There are a few, but much more limited options compared to 18650.
I wrote this to the Freelancer, but she made the design with a 4.2V Li-Ion charge controller. I saw it to late and already ordered the PCBs. So now its a 18650 Li-Ion cell that will be used 😁
For the function its not important. On the plus side we safe a few grams with the 18650 cell!
---
### Author:  [@KBM](https://dao.arrowair.com/u/KBM)
#### Post date: [September 24, 2024, 2:23am UTC](https://dao.arrowair.com/t/signal-distribution-box/49/7 "2024-09-24T02:23:06Z")
18650 LiFePo4 manufacturers are evolving to 4680 batteries now