To the power off

@ Jason - I never thought that dimming a light /Speed control of an AC Motor with Zero crossing detect could be that simple. :clap:
I was looking for something like this a while ago, and never could find anything that simple that I had the Impression of that it could actually work.

Think I got there. A night’s sleep certainly helped. PCB layout changed too. I think I incorporated your TVS and snubber suggestions as well as increasing the PCB size, moving the Gadgeteer socket and I added another set of holes that could be used to fix a protective cover. There’s a keep-out area marked on the silkscreen too.

Thanks for all you suggestions on this. Hopefully it’s not too far away from manufacturing now.

Did you consider also adding an actual routed slot for isolation ? You’ve come so far… :wink:

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C1 in 0603 ? :think:
Which voltage you would expect across C1 if triac is OFF ?

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Arrrhhhh!! Overlooked that :wall: . Thanks for picking it up. Going to change R ( and C ( to 1206 or 1210 I think. Should they be bigger?

I hadn’t considered it, so far. I’ll see what’s possible as it’s a great idea. :clap:


Place C1 & R3 closer to the 230V connector and as Lutz1 mentioned… Use a 400V capacitor and for R3 reserve space for a 2Watt resistor

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Another idea is to add a LED to each channel so that you can see if a channel is ON/OFF. might be handy during software development.

@ RobvanSchelven - LEDs in place. Other stuff on way.

Thanks again to all.

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@ Jason - Cool project Jason. I’m very interested to hear how it works out. This will be a nice community creations board too. Hope you are planning on doing that?

@ RobvanSchelven - Any thoughts of the power requirements for R2? Should it be the same as R3?

I think 0.5 watt 0805 should be enough. if you take a look at the datasheet of the optocoupler
Intelligent Power and Sensing Technologies | onsemi Page 4 shows a schematic under Typical application. You see a another resistor drawn at pin 4 of the optocoupler to the triac. You could add a landing patern 0805 in case its needed.

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Nice job and design!. If you are going to produce a few proto’s count me in for one… I am happy to buy one !

@ RobvanSchelven - It’s not tracked yet, but here’s the final layout (I hope). Larger components, TVS, cut-outs, larger copper area for heat sink, moved connector and hatched keep-out area.

Apart from tracking, I think I’m there. I want to do some final testing of the design before I push the button, but it will happen in the next week or two.

Thanks for your invaluable input. I’ll keep you posted on prototypes


Looks great ! Thanks

Hi Jason, another great project.

It’s only a minor thing but I like things like this to be correct :slight_smile:

I see looking at the 3D model that you don’t have any Layer Stack setup as the PCB appears thin. If you use the attached values for Layer Stack Manager you will get a better looking PCB in 3D and if you export this, the board thickness will be more accurate.

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@ Dave McLaughlin - I noticed that too right after I posted it. It’s fixed already and looks much nicer.

Many thanks.

@ Jason - Exploring the drawing i was wondering if the gadgeteer connector doesn’t need to be rotated by 180 degree.

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Maybe. Let me take a look later. I hope to track the PCB tonight too.

@ RobvanSchelven - Agreed. The existing modules have the tab on the other side so I’ll rotate it as I lay it up. Thanks.

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