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Relay
#21
My mechanical relay’s are sticky as well.
After 2 years the reliability drops quite hard in my experience.
Already got 2/16 relays stuck in the on position and 1 stuck in the off position.
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#22
(11-03-2018, 05:30 AM)fietsenrex Wrote: Did some asking around at my workplace and multiple electricians but the RC snubber is only reccomended when switching highly inductive or capacitive loads.
But since I’m not switching high-power coils or anything I was advised not to break my head on it :p
So I only need to figure out which Logic mosfet i need

Thanks for the info fietsenrex, I'll probably leave it as it looks like nobody really uses a snubber.

You might consider the IRLB8721 for a mosfet. These are nice because they can handle a really large load without a heat sink. Way overkill for a relay but hey they are easy to work with and will cover just about anything. These turn on with 2.35v so they work with any MCU.

https://www.infineon.com/dgdl/irlb8721pb...6056732591

(11-03-2018, 06:18 AM)aquaalgae Wrote: The Reef Angel outlets don't have it but the ones you make do Rob? The reason I ask is because I was having all kinds of issues with Reef Angel including outlets not coming on/off when they should and weird flickering on the PWM LED channels. If I unplugged most of the stuff from the outlets, things would go back to normal.

Yeah they doesn't have the snubber but neither do I or likely anyone else. I might have just got caught up in it, thinking about it now maybe devices that require a snubber have that as part of the circuit for the device, that would seem to make more sense. Not sure why you were having that issue, sounds like noise was maybe getting into the DC side of the circuit, not sure. I use to have some similar issues were noise would get into the display and lock it up but that's been long solved. The way it's setup everything is isolated except the GND and I'm probably going to isolate that as well. I haven't had any major issues from the power bars except an odd relay dying but with the GND isolated as well it's even more protected. I just got some PH and EC circuits I made up that have full isolation, after I test it I'll pass it on to the power bars.
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#23
The “old” IRLB8721 is retired, currently it is the IRLB8721PBF which keeps popping up in my search for a Logic fet
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#24
Ah well it's the same anyways. Another that might be cheaper is the IRL540N you can get bags of them on ebay and should cover most projects. Here's a video I like that helps explains how to choose mosfets.

https://www.youtube.com/watch?v=GrvvkYTW_0k
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#25
Just a off-topic question, i could ofcourse use them to make my fans speedcontrollable?

Nice video btw

Nice video btw
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#26
Yeah he does a good job explaining. If you connect them to a PWM output you can control speed so you could connect them to LED channels. The DC accessory ports on the controller are capable of speed control and will be adding in v5.
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#27
Great Thanks.
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#28
came across this one, do I also need a 1K resistor?
http://www.pi3dscan.com/images/irlb8721.jpg
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#29
Yeah you should use the 1k resistor.
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#30
just for my peace of mind....
I tested the SSR using a MEGA loaded with the blink sketch.
when the LED is set to HIGH the SSR ignites and when it goes to LOW the SSR stops, just as expected.
but if the signal drops when the SSR is powered it remains on, even if I powercycle the SSR it remains on

guessing this is normal, but does the robo-tank also sets the digital output to LOW like in the blink sketch?
I think I already found it in the outlet tab but I want to know for sure
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#31
That is normal for the SSR, if you wanted it to go on or off when the signal isn't present you would add a pullup or pulldown resistor on the signal from SSR, I know you don't need that just saying. The controller does set the pin LOW and HIGH but it's reversed in the code, LOW is on, HIGH is off. If all your outlets are wired the same you can swap the LOW/HIGH in the code that you found, only one location for each. However if you're only adding a couple like this to already wired power bar we can add an if statement so it does right way for proper outlet number. Let me know your setup and we will get it right.
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#32
Why is it reversed?

For now it would be ON if the output is HIGH
I wouldn’t know how to change that on the hardware side, I was under the assumption that if the outlet was HIGH it means the relay is ON.
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#33
I just refreshed my memory as to why it's reversed and it's been like that from day one when I didn't know what an Arduino was. I got that from a bad example I followed or based on how I wired my power bar and never changed it because I didn't want to mess up everyones system. It wasn't a big deal with those relay modules because they could be wired normally on or normally off. In the end neither setup is better but yes HIGH makes more sense to turn on and what an SSR expects.

If you don't want to mess with components which I understand we can easily add a little code to sort it out. Just need to know which outlet number/s the SSRs are on. For example if outlet 2 is SSR and the others are original we can add.


Code:
if (_outletID[loc] == 1) digitalWrite(_pin[loc], HIGH);
else digitalWrite(_pin[loc], LOW);
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#34
All 16 outlets will be fitted with SSRs ;)
So it Just has to be swapped over, But I’m a special case anyways since I got custom library’s for the display :p
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#35
That's a nice upgrade and it'll make the code change super easy. You only need to change LOW to HIGH and HIGH to LOW in the outlet.h tab on controller sketch. The key now is to remember to make the change before doing an update or you'll get a surprise. :)
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#36
I’m surprised every update when my screen gets all scrambled and I forgot to comment out the wrong screen :p
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#37
lol... the other day I chased my tail for about an hour, I changed Wire1. to Wire. for the power bar then the next day I uploaded to controller and power bar wouldn't switch, I was freaking out thinking something went bad and finally realized I made that change haha.
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#38
Finally got the new powerboard finished.
https://flic.kr/p/2jwwXni
In the outlet.h there are 2 HIGH and 1 LOW
Just to be sure, I need to change all 3 right?

Still using V4.2 by the way
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#39
That should keep you going, looks great.

Yeah those are the lines you need to change, the extra HIGH is during boot up, that can be LOW or HIGH.
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#40
Got is sorted, thanks for the help :)
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