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Energy Monitoring AC Power Bar Coming Soon
#1
Hi, I've been working on some improved AC power bars so I'm setting up some pre-orders if you want to save some money and help with the development.

There's two different power bars, the main difference is one will monitor power consumption for each individual outlet. I'm confident the non-monitoring power bar will be ready once I get the PCB's as this board is based off the layout of the current power bar so I'm estimating 4-5 weeks to ship. 

The other with power monitoring will take longer as it has a microcontroller (brain) of it's own so I have to take time to write the code for it, it's all pretty basic but will still take time. I haven't used this microcontroller yet so it's also possible I make a mistake on the layout and have to order new PCB's which would add about a 3 weeks delay. I've taken much time to do everything possible so that doesn't happen but it's possible. I expect to ship this in 6-8 weeks, that's why you can save more on this power bar with a pre-order.

The focus has been to create something safe and high quality instead of budget, based on my experience with the current power bar I'm confident this will be a success. The only problem I have with the original power bar is sometimes a relay can prematurely die which is likely related to an inductive load and that's been covered on these power bars with snubbers and TVS circuit for over voltage. Along with that everything else has been improved, the new PCB's will have 2 ounces of copper instead of the typical single ounce which will allow them to carry much more current then they will ever see. The power bars contain no internal high voltage wires so there's no chance anything can short out or wires degrading over time. The only wires are some 5v jumpers going to a separate PCB for the indicator LED's. 

There's independent fuses for each outlet, if a piece of equipment goes bad and causes a short the fuse for that outlet will blow protecting the rest of the power bar and equipment but more importantly everything else will remain running. There's also a main fuse which I've settled at 12 amps. I was going to push to 15 amps as everything is capable but for extra security went with 12 amps, the 240v version will be fused at 10 amps. Each individual outlet will be fused at 6-8 amps, that's still to be determined. I also removed the main on/off switch so one less thing to go wrong, there's really no reason for it and this is the only other thing that has caused an issue in the past.

Another nice improvement is some fail safes. With the current power bar if you unplug it from controller all outlets turn on which obviously has its issues. If the controller was restarted the outlets would all be on for about 5 seconds till the controller was able to set them. This has been solved on both power bars but the energy monitoring power bar is a little better because it a microcontroller of its own, the non-monitoring doesn't. But in the end you can get the same results. Now both power bars have some jumpers on the PCB for each outlet, you can set these so outlets are either on or off if no controller is connected. For example if you have the power bar on a UPS (uninterrupted power supply) when the power goes out all the outlets will switch to the mode the jumpers are set for. Once the power comes back on and controller starts up all the outlets will resume back.

The power bar with energy monitoring can be pre-programmed through the display so a little easier to work with but if the microcontroller fails in the power bar the PCB jumpers will still do what they should. There will also be an additional LED on this power bar which will turn on if a connection to the controller is seen. A little extra I'm going to add, if the electricity goes out or power bar is unplugged from controller the power bar will record this and once connection is resumed again the controller will send an email telling you how long it was disconnected and all the vital parameters of your aquarium. 

On both power bars there's LED indicators for each outlet so you know if they are on/off and there's a spare USB port so you can plug in another power bar or other Robo-Tank accessory.

At the moment I don't have a list of all the data the energy monitoring power bar will produce but will be the general voltage, amps, watts, cost and anything else I can dig up. I want it to produce every number possible so I will be checking all alternatives. All the data will be stored in logs so there will be graphs for everything and you can use the data to create alerts and custom rules. Over time I also plan to add something so it can learn how much current is typically used for an outlet and if it goes out of range you'll be alerted, things like that but you'll be able to setup rules to do that until then. For example if you have a heater plugged in which drew 2 amps turned on you could set a rule/alert to tell you it's over or under which would likely mean something is wrong with the heater. There's a lot that can be done with this info.

These power bars will also be fully serviceable, trying to design for this was a challenge but I came up with a nice solution with the case design. On the current power bar the outlets are pushed through the case and soldered to the PCB, because of that it's a literal nightmare to remove the PCB. With this case the outlets will push through a flat template which will hold them all in place. This will be pushed into the case which will have standoffs to screw the plate on the outlets. There will be standoffs also on the lid so the top of the power bar doesn't see get any pressure placed on it like the current one does.

Here's the links to each listing and as a bonus all the pre-orders shipped outside North America will be shipped via Chit Chats through the USPS mail system which will save you $40 or more. This is a company that just moved into my province, because shipping with Canada Post is really expensive this company collects packages and drives them across the US border and ships with the United States Mail Service. The beauty of this is the shipping includes full tracking, with Canada Post it costs $40 extra for tracking which is crazy. Unfortunately this is only available for the pre-orders at this time as this company isn't in my city so I have to ship them with Canada Post to their location first and that only works if I ship multiple packages at once. Because of this expensive it doesn't pay off for a single package. They do have plans to open in my city but could be a while.

I will be making a version of both power bars using universal outlets that work for EU, AU, US and UK however that will be an additional 3 week delay as I need to verify the PCB's for the North American version first.

This is the version without power monitoring.
https://www.robo-tank.ca/en/Robo-Tank-Pl...90431c814e

This one has power monitoring.
https://www.robo-tank.ca/en/Robo-Tank-Pl...903e219d01

And finally here's some pictures of what they will basically look like. Already there's a change, you see only 8 LED's but one will have 9 and the other 10.

[Image: SSR_multi-view.jpg]



[Image: SSR_CT_multi-view.jpg]
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#2
Nice one. It is good to have power meter in aquarium use. It is nice to see total consumption, cost in euros / dollars etc :)
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#3
(04-07-2019, 11:58 PM)niksunen Wrote: Nice one. It is good to have power meter in aquarium use. It is nice to see total consumption, cost in euros / dollars etc :)

power consumption is nice to see if equipment is going bad or something, so you would need a graph for that.
but it's a good thing that it will be a cleaner install and probably safer as well
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#4
Yeah niksunen, you know how good that info is. :) Thanks to you now I have to work hard to make my UI better than yours lol...

PCB's are definitely safer than using wires, for sure look safer. I enjoy assembling the power bar I already have as it's so easy, playing with wires isn't fun.
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#5
Hi, just thought I would post an update on the power bars which are coming along nicely but I did have a couple set backs. First when I designed the circuit board I forgot about the transformer required to monitor voltage, downside to this is the smallest available is quite large but it still fits.

I've been doing lots of variations and testing for the current monitoring, I'm pretty happy with how it's coming and think the accuracy will be ok. The readings are all stable and when comparing to my off brand kill-a-watt meter and regular volt meter the amps always match or definitely close enough. When comparing AC voltages I believe the kill-a-watt is wrong as my setup matches my volt meter which I trust.

Now when it comes to power factor this one doesn't always match up with the kill-a-watt and I have nothing else to compare so I'm not really sure which is correct. Some things match up and some are off by maybe .2. I'm basing mine off the popular OpenEnergyMonitor instructions for an Arduino so I'm fairly confident things are as good as they can be at this price range.

I've gone through a few different current transformers as I'm not really happy with the low end scale, anything under 5 watts doesn't really show up so I've ordered some more parts which should be here Tuesday and I will see if this can be improved. So I haven't nailed down the final design yet but it should be this week.

With that said I don't think it will be the most accurate, I'll say within 5-20% depending on the load, better accuracy with higher loads. In the end there's no way for me to really know without expensive equipment but don't let this worry you. Is it really that bad if a device truly drew 150w but this said 140w, obviously the cost shown over a month would be off some but the main purpose to monitor equipment is still achieved. I only mention this because I don't want to oversell it and say it's the most accurate but it's definitely within range and works well.

A bigger issue I'm having is with the SSR's, they work good but if pushing 4 amps they start to warm up more than I would like, still can touch easily but I want less. When pushing 7 amps through them they get way too hot to touch so I've ditched them and have been researching TRIAC's which is essentially the same thing. It's added more work for assembly but I'm happier using this approach vs an SSR as I don't know what's inside the SSR, building my own I can be sure all the components are high quality, over rated and have the proper safety ratings. I should have the final design finished this coming week and will post details then.

For the software this is what I'm doing for now, more related features will be added over time. 

If the software detects power monitoring and you visit the screen to turn an outlet on/off manually you'll get the following view. The watts for each outlet is shown under the outlet icon and a summary for the overall power bar is shown at the bottom. 

The controller will tally daily and monthly totals which will auto reset and the data will go into a graph which can be viewed for either. It'll also run an overall total which can be reset any time. Later I'm going to have a list in a spreadsheet view that will show daily and monthly totals as well so you can easily do comparisons over time. I'll break this down into outlets and overall power bar views.

If you touch the "Rate" you can change it and press and hold the total section and it'll reset as well. 

[Image: Main_AC_Manual.jpg]

The screen below is a view you can access from a shortcut on the home page. This shows all the totals for each outlet. Unfortunately I couldn't get all 8 outlets on one screen so added a button to toggle between outlets on a power bar and another button to view a different power bar. 

The "Rate" shown here and above is all the same, if you change one they all change, I only show it for each outlet because it fits.

The green "Set Range" box can be used to setup alerts, when you press it you get the next image.

[Image: Main_Energy.jpg]

This screen allows you to setup an alert for each outlet. If an outlet is turned on and the power being drawn doesn't fall in this range you will be alerted. Sorry the "home page notification" alert won't work yet, it's still coming.

[Image: Main_Energy_Alert.jpg]

The scrolling parameter box on the home page will also have the option to show the total power consumption, etc... for a power bar.

That's all I have for now, if you have any suggestions let me know.
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#6
Hi, so I've been busy with the power bars and finally got some boards ordered yesterday and should have them soon. 

As I mentioned instead of SSR's the switching is done with Triacs. I've settled with some that handle 16amps RMS, unfortunately these still put out a lot of heat under high loads and using a larger Triac doesn't help as it still needs to dissipate the same power. This was a bit of a challenge because I discovered it takes a large heat sink to keep it cool to my liking when pushed to 7 amps which I've settled on for the limit on an outlet. There's no way each Triac could have it's own heat sink as they would be too large, expensive and a waste overall. I needed something they could all share but couldn't find a pre-made sink so I went to the metal shop, got all shapes and sizes of aluminum and started testing. 

In the end from what I had the best was a solid chunk of aluminum 16mm x 16mm x 150mm, this worked better than tube or angle. With this it only starts to warm up if a Triac is pushed to 6.9 amps. If the Triac is pushing 4.8 amps the heat sink basically stays cool. If 2 Triacs are being pushed to these levels the total is 11.7 amps which is just under the max 12 amps the heat sink does warm up but still can be easily touched. With the board finished I can actually fit a 200mm long heat sink so there will be an extra 25% which will go a long way. I still may use channel with the longer length as it might get warmer but should cool quicker than the block but in this case the block might win as it might never get above a temp which it's looking like. This is also the worst case scenario, as more current goes through the Triac the heat really adds up and thankfully it's only possible one Triac can actually hit 7 amps as two would be 14 amps and blow the main 12 amp fuse. When I push it with 3.6 amps the heat is manageable with a small sink so I'm confident if 3 Triacs was running this which would be 10.8 amps the heat would be ok. And when you break it down into amps per outlet, 12amps / 8 outlets = 1.5 amps each the heat is much lower. It's not really possible to setup 8 Triacs on my desk but will test more when I have a board assembled. Sorry for rambling but thought someone might find this interesting.

The rest of the components are over sized and have been carefully selected, they have the highest safety ratings and from trusted manufactures ordered locally. Unfortunately with this design the overall cost did go up compared to the SSR's but this should be a nice power bar that will last. Each Triac has been isolated from the DC side up to 6700 volts and there's a heavy duty snubber that will protect from roughly the same over voltage caused from inductive loads. The current power bar has neither of these features and I believe the reason why a relay can die prematurely and because this is overdone it should handle the nastiest pumps out there.

The energy monitoring power bar has an ATmega32U4 microcontroller running at 16 Mhz (equivalent to Mega 2560), this is dedicated to reading power levels on each outlet. Reading consumption from 8 outlets does take some time, it takes a minimum of 5 seconds to read all 8 outlets with some stability. Set like this the numbers do drift slightly, for example you might have a range of 25.0w - 25.3w for a given load but if the number of samples for the reading is increased it can be rock solid at say 25.1w. Obviously I like that better but then it takes maybe 10 seconds to read all 8 outlets which I feel is a little long. Because of this I'm going to have it adjustable if you want to increase accuracy. Now don't let that scare you, it works good but if you plug in a device and expect an instant reading you will be disappointed. 

Last update I mentioned anything that was less than 5w didn't work, this has been improved quite a bit using a different transformer, resistors and code. I have a couple small lights that have a 3 watt bulb and now they shows up the same as my kill-a-watt knockoff. I also like the power factor numbers better, they feel more accurate now. I also expect things to be even better once everything is mounted on the PCB instead of using jumpers and filtering caps not ideally placed on breadboard and other boards.

And finally I can't post without some pics so here's the updated board.

[Image: ct_Front.png]

[Image: ct_back.png]
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#7
Someone asked for some sample readings so I thought I would post them as well, these are actual watts and shows the stability in 100ths but I'll only be displaying 10ths.

realPower = 23.92
realPower = 23.96
realPower = 23.97
realPower = 23.99
realPower = 23.96
realPower = 23.90
realPower = 23.95
realPower = 23.94
realPower = 23.94
realPower = 23.98
realPower = 23.98
realPower = 24.00
realPower = 23.90
realPower = 23.96
realPower = 23.97
realPower = 24.01
realPower = 24.02
realPower = 23.94
realPower = 24.01
realPower = 23.99
realPower = 24.03
realPower = 23.99
realPower = 24.03
realPower = 23.92
realPower = 23.98
realPower = 23.96
realPower = 23.97
realPower = 23.94
realPower = 24.00
realPower = 24.04
realPower = 24.02
realPower = 24.00
realPower = 24.03
realPower = 24.02
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#8
I got the boards last week and I'm happy to say they work good. I've got the power bar running on the controller and working on some code and have to finalize the case design. I must say it feels strange not hearing a click, I setup some custom rules to turn an outlet on/off with a float, when I move the float as fast as I can I get a nice strobe light effect. :) I don't have pictures today because I want to mount the heat sink first but I don't have the parts. I was going to pick them up this morning but they are closed for long weekend so now I have to wait till Tuesday.
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#9
I got the case designed and heat sink mounted so here's some pics of it ready to go.

The one thing that really bothers me is the placement of the LED's, I want them to the right more but I really screwed up on the board that holds them as I made it so large, I'm lucky to get it in without having to increase the case size just for it. The power bar is 245mm x 153mm x 49mm and all the outlets are flush with the top.

[Image: DSCN7485-Optimized.JPG]

This is everything mounted in the case, there's 8 - 7 amp fuses for each outlet and a main fuse of 12 amp. Each fuse holder has the outlet number as a label. 

[Image: DSCN7509-Optimized.JPG]

After removing a few screws and some bolts in the AC power socket the board lifts out the case and this is what you get. This allows easy servicing if anything ever goes wrong which I don't expect as all the parts are good quality and some have already proven themselves, always got to add that in. ;) All the parts can be replaced without much trouble. 

At the front of board you can see the large heat sink. I like how this turned out as it works well and overkill but it does add quite a bit of weight, the whole power bar in case weighs 910 grams which I think is more than double the current power bar so you wouldn't want to drop it.

The main heat sink is 7.6" x 5/8" square aluminum and the front is 7.2" x 1/8" flat aluminum which makes a triac sandwich. They're held in place using 3D printed brackets which work really well. They wrap around the sink so it's can't be pressed into the board and there's one screw at the top which squeezes things together so it's no going anywhere, the brackets are solid so the screws have a good bit as well.

[Image: DSCN7470-Optimized.JPG]

This is same as above but before the outlets are soldered in place, here you can see the white heat transfer compound on each triac.

[Image: DSCN7473-Optimized.JPG]

This is the back side of the outlet plate.
[Image: DSCN7483-Optimized.JPG]

This is the empty case and lid. You can see the LED board pressed into it, this will be glued in placed. I must say I really hate these lights though, they add a lot to the assembly time and because it requires messing with wires I can't say the power bar is wireless internally anymore. :(

[Image: DSCN7480-Optimized.JPG]

The "P" LED is for power, the others are for outlets obviously.

[Image: DSCN7489-Optimized.JPG]

The 2 USB's on the side are used to connect it to controller and plug in another accessory like a power bar or pH circuit. Doesn't matter which is used for any function. 

[Image: DSCN7499-Optimized.JPG]

This is the back and where the AC power socket is. There will also be 2 bolts on the side holding it firmly in place but for these pics I just placed the board in. Some of the outlets aren't flush because I made the holes a hair to small so it's a little tight and I didn't want to fight it, they will be flush not to worry. ;)

[Image: DSCN7503-Optimized.JPG]

I also changed the page to view energy for each outlet. I didn't like only 4 outlets being visible so with this you can view all 8 outlets and using the menu switch what's being viewed.

Instead of posting 4 pictures I put each view type on a row, power, energy cost, kWh totals and alerts. The charts for now will take you to the current graph menu but it'll return you here when you leave. 

For the alerts I'm going to have the controller generate the values. Whenever something new is plugged in you can press the "train alarm" button and it will generate a min/max after 24 hours and will display what it calculated. At the bottom you can press the alert type icon, it'll turn green and you'll get the alert if the outlet is on and not in the correct range.

The 7 and 30 day estimates for the cost and kWh will likely update every 24 hours.

[Image: Main_Energy3.jpg]
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#10
nice progress so far
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#11
thanks
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#12
Hi Rob, are you already selling the 230V version? thanks
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#13
Hi Simon, I will have some with universal outlets but don't have the boards just yet, plan to order some soon. If you only want the board for a DIY the one I have can be used. The universal outlet bar will only have 7 outlets though as I need the space for a transformer.
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#14
Thank you Rob, With only the PCB I can have all 8 outlets on a 230V power bar? thanks
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#15
Yeah that is possible. The 120v boards just need a short jumper added (which I would do) because of that transformer then it can be used for 230v, you can solder the wires from outlets directly to the board.

One other thing, I haven't been able to tune the energy consumption for 230v as I don't have it. You can either do this if you have/get one of those Kill-A-Watt meters. This would involve uploading some sketches to the controller which will change the calibration values in the power bar. If you don't want to do this once I have the correct calibration values you can then upload the changes.
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#16
Perfect! Thank you very much!! :)
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