02-18-2018, 03:06 PM
Hello everyone, I've been working on a circuit board for the power bars to make assembly easier and would love to get some feedback to see if anyone thinks there could be issues or improvements.
The board is solder directly to the AC outlets then 3 AC wires need to be soldered from the AC socket on the case to the circuit board, and it's up and running, the board is also fully isolated from the controller using optocouplers.
The power bar would no longer have a power supply installed because they are so big and the case needs to be large to accommodate it plus if the power supply dies its difficult to replace. I know having an external power supply has downsides too because it uses up another precious AC outlet in the wall so what I did was added a movable jumper to the circuit board so outlet 8 can always be on and used for the 12v power supply to power up the controller. This way you save the plugs in your wall and still have 7 available in the power bar.
So now 12v from the controller goes into the power bar, then into some DC-DC converters and it powers up the optocouplers used for isolation. Then there's a mini AC-DC power module on the circuit board that puts out 1000ma and used to power the relays making it fully isolated. 99% of currently users are only partially isolated unless you added a second power supply for the relay module.
I also added an I2C IO expander so only 4 wires (USB cable) is needed to connect to Robo-Tank instead of that hard to find expensive VGA cable, in the future I can update the code so 8 AC power bars could be connected instead of 2 currently allowed. This won't affect any current users as there'll be an option on the display for the power bar type attached.
Here's some technical data, if you see an issue or something that could be improved please let me know. All the components for relays are the same as the blue 8ch relay modules.
The image below is for the universal AC outlets, I'll have one for the other outlet types as well. The board is 193x137mm
This is the front and what you would see when you open the case. The green part of the board in the red circle I drew is where the AC Hot and DC ground plane come close, I added cutouts there which can't be seen so it can't create a bridge, same as the blue 8ch relay modules.
![[Image: Power-Bar-Universal-RevA-Front.jpg]](https://www.robo-tank.ca/pictures/Power-Bar-Universal-RevA-Front.jpg)
This is the back of the board and can't be seen when mounted.
![[Image: Power-Bar-Universal-RevA-Back.jpg]](https://www.robo-tank.ca/pictures/Power-Bar-Universal-RevA-Back.jpg)
This side has the 8 AC relays, AC-DC power module (HLK-PM01) and electrolytic capacitors.
The downside to I2C is cable length is quite limited, 10ft would probably be the maximum so I'm also going to make I2C extenders so longer cable could be used. I'll also have an expander for the controller so you could plug into the main I2C port and have a bunch of USB I2C ports for the power bars and whatever else might come.
It'll probably be a month before I have everything to test, I'll start with the North American outlets and once its working then I'll get for other outlet types.
The board is solder directly to the AC outlets then 3 AC wires need to be soldered from the AC socket on the case to the circuit board, and it's up and running, the board is also fully isolated from the controller using optocouplers.
The power bar would no longer have a power supply installed because they are so big and the case needs to be large to accommodate it plus if the power supply dies its difficult to replace. I know having an external power supply has downsides too because it uses up another precious AC outlet in the wall so what I did was added a movable jumper to the circuit board so outlet 8 can always be on and used for the 12v power supply to power up the controller. This way you save the plugs in your wall and still have 7 available in the power bar.
So now 12v from the controller goes into the power bar, then into some DC-DC converters and it powers up the optocouplers used for isolation. Then there's a mini AC-DC power module on the circuit board that puts out 1000ma and used to power the relays making it fully isolated. 99% of currently users are only partially isolated unless you added a second power supply for the relay module.
I also added an I2C IO expander so only 4 wires (USB cable) is needed to connect to Robo-Tank instead of that hard to find expensive VGA cable, in the future I can update the code so 8 AC power bars could be connected instead of 2 currently allowed. This won't affect any current users as there'll be an option on the display for the power bar type attached.
Here's some technical data, if you see an issue or something that could be improved please let me know. All the components for relays are the same as the blue 8ch relay modules.
The image below is for the universal AC outlets, I'll have one for the other outlet types as well. The board is 193x137mm
This is the front and what you would see when you open the case. The green part of the board in the red circle I drew is where the AC Hot and DC ground plane come close, I added cutouts there which can't be seen so it can't create a bridge, same as the blue 8ch relay modules.
This is the back of the board and can't be seen when mounted.
This side has the 8 AC relays, AC-DC power module (HLK-PM01) and electrolytic capacitors.
The downside to I2C is cable length is quite limited, 10ft would probably be the maximum so I'm also going to make I2C extenders so longer cable could be used. I'll also have an expander for the controller so you could plug into the main I2C port and have a bunch of USB I2C ports for the power bars and whatever else might come.
It'll probably be a month before I have everything to test, I'll start with the North American outlets and once its working then I'll get for other outlet types.
