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Dual SSR inside a PowerStrip — Parallax Forums

Dual SSR inside a PowerStrip

tonyp12tonyp12 Posts: 1,950
edited 2013-11-19 10:03 in Robotics
Step1: Cheap $4 power strip from Harbor freight

Step2: Solder pcb board with CPC1966B (3Amp up to 240 VAC) SSR's
http://www.mouser.com/Search/ProductDetail.aspx?R=CPC1966Bvirtualkey56550000virtualkey849-CPC1966B
and PS2505L-1-A Transistor Output Optocoupler (for mains hertz detection)
http://www.mouser.com/Search/ProductDetail.aspx?R=PS2505L-1-Avirtualkey55120000virtualkey551-PS2505L-1-A

Step3: Cut the copper bar inside so it line up with the pads on the back of pcb. cut a hole in plastic for RJ12 6P SMT JACK
http://www.mouser.com/ProductDetail/Molex/85513-5002/?qs=%2fha2pyFaduikdRnLaL3shAQxtW4zSBwt9i32RLDmj%2fQ%3d

Step4: Solder pcb to copper strips inside power strip and also attach Neutral (only used for Opto) and Earth to pcb.

Step5: Control the signal with a Prop or Stamp , put a pull-up (~10k) on the Hertz detection pin it will be a 1 for short period during the cross over.

The SSR have zero-cross turn-on circuitry, so it will not go on right away but at next zero cross.
I tried to get dimming by using the added hertz detection and then a slight waitcnt and turn off the SSR, but no-go as the SSR must also have zero-cross turn-off.
You could toggle on/off after each cross over, but 30hz does have visual flicker even on incandescent bulbs so the hertz detection is only good to detect that main power is on.
640 x 450 - 106K
640 x 420 - 106K
640 x 554 - 82K
640 x 415 - 73K
640 x 704 - 96K

Comments

  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-09-03 09:44
    This is a pretty neat idea, what do you intend to plug in to these outlets? I think a neat idea would be to use them to control the heater in an el cheapo 120v soldering iron. Maybe add some WiFi to the prop and turn your lights off over the web?
  • evanhevanh Posts: 15,405
    edited 2013-09-03 16:20
    Due to the nature of triacs and SCRs, when they say it is zero-crossing they are talking about the turn on point because the turn off is always zero crossing. There is triacs that don't do aero-crossing.

    It's not a safe design if you don't have full isolation to your controller. From your description of the AC sense I suspect you are tapping neutral as a reference. Bad design!
  • tonyp12tonyp12 Posts: 1,950
    edited 2013-09-03 17:11
    >neutral as a reference
    No I don't, neutral is only used on the high-voltage-side of the opto-insolator
    You can not drive ±160v in series with a 47K resistor (use 100K for 220V) parallel-LED without ground (e.g neutral)
    I could also used earth, but even tiny 4mA is frown on as earth is only emergency ground.
    Check out data sheet.
    http://www.mouser.com/ds/2/286/ps2505-34260.pdf


    The SSR are are "highside" switches and don't need neutral at all.

    MCU Vss goes to the board but is never mixed with neutral or earth.

    I will put up schematic soon.
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2013-09-23 04:53
    Did you make that PCB yourself? I'd be curious to see it. This looks like a project I've been wanting to do, but having gotten around to yet.
  • tonyp12tonyp12 Posts: 1,950
    edited 2013-11-17 20:03
    DualSSR.jpg?psid=1
    DualSSR_Sch.jpg?psid=1


    Link Below is Zip file with Schematic and Dip file (and 3D models)

    Warning: 115AC is dangerous!

    https://onedrive.live.com/redir?resid=6D7787B33D967B1A%214163
  • Mark_TMark_T Posts: 1,981
    edited 2013-11-18 12:11
    What physical spacing do you have on that PCB between mains and low voltage? Are you aware that if its too small the first ant to crawl around
    inside it could kill you? It's usual to have 0.5" spacing and/or a routed slot in the PCB between dangerous and low-voltage sides for this and
    other reasons (such as condensation). The easiest fix for this is to pot up the high voltage parts of the circuit in epoxy so nothing can touch them.
  • tonyp12tonyp12 Posts: 1,950
    edited 2013-11-18 14:01
    DualSSR_Layers.jpg?psid=1
    Brown = Mains
    Green = Earth ground
    Blue = MCU traces.

    Solder mask is a pretty good insulator, so the only high volt part on the pcb's topside that are open to the air is the 8 upper pins and small pads.
    I can see I did not tent the via's on this side, that is a good idea to do.
    Due to size limit imposed probably not the best spacing.
    Should move down the Rj12 connector a little, so the Earth barrier would be complete.
  • Mark_TMark_T Posts: 1,981
    edited 2013-11-19 09:19
    tonyp12 wrote: »
    DualSSR_Layers.jpg?psid=1
    Brown = Mains
    Green = Earth ground
    Blue = MCU traces.

    Solder mask is a pretty good insulator, so the only high volt part on the pcb's topside that are open to the air is the 8 upper pins and small pads.
    I can see I did not tent the via's on this side, that is a good idea to do.
    Due to size limit imposed probably not the best spacing.
    Should move down ( or rotate left) the Rj12 connector a little, so the Earth barrier would be complete.

    Soldermask is not mains rated to my knowledge, I wouldn't trust my life to something like that.
  • tonyp12tonyp12 Posts: 1,950
    edited 2013-11-19 10:03
    If the worry is that a 10mm ant gets in there, epoxy the pins.
    Could also plug it in to a GFCI outlet for extra protection.
    Updated it a little, with a different connector 12.5 mm creap should be possible.
    I think 1.6mm pcb thinkness is OK?, as there is mains on the other side that is pretty close to connector.
    And maybe it's better not to Earth Ground the PCB?
    SSR2B.jpg?psid=1

    8mm looks like the recommended
    KwIKq.jpg
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