Self Latching Relay

Discussion of the physical aspects
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oakbarn
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Self Latching Relay

Post by oakbarn »

I have been trolling the internet and have asked on other electronic forums, but since I want to use with the BCS, I am repeating it here. :P
Question:
Is there a board out there that will work? If so, could you point me to it.
What I need:

Self Latching Relay Board?
I am confused by what I found on the internet as it talks about manual buttons and triggers. I want one with a trigger to go from “NO” to closed.
I want a "switch" that is "NO" but electrically activated to "Closed". Once Closed, it stays that way until either manually or electrically returned to the "NO" State.

Basically I want to replace some manual Toggle Switches that I had planned set up on my Fermentation BCS. I am in the “building mode” now and while I have almost everything I need to start, I want to add automated switches that will jump to the correct State if I have a power outage while I travel.

I live outside of Dallas and we have frequent but brief power issues during Thunderstorm season. I do have the BCS on a Battery UPS.

This is my planned Process. I have the Toggle switches but have not wired my fermentation BCS yet.
It would be nice if the BCS could trigger the latching relay but I have no problems using an Out SSR to drive the trigger for the latching relay.


I will need to tweak this a bit but this is the "plan":


Process Lager
Run at Start Up
Timer 0 = Fermentation
Timer 1 = Primary
Timer 2 = Diacetyl
Timer 3 = Change


State 0 = Maintain Primary Temp @ 54 for 8 Days
Timer 0 = Fermentation = Enabled = Count Up
Timer 1 = Primary = Enabled = Count Up
Timer 2 = Diacetyl
Timer 3 = Change
Output 0 Glycol Chiller Maintain Primary Temp @ 54
Output 1 Glycol Valves Maintain Primary Temp @ 54
Exit 0 = Timer 1 Primary => 192:00:00 (8 days) goTo State 1
Exit 1 = DIN 0 (Step 1) = On goTo State 1
(Exit 1 : This is a Manual Toggle Switch (DIN 0) that I want to automate)
Alarm = None
State 1 = Ramp Primary Temp up to 70 over 3 Days
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary
Timer 2 = Diacetyl
Timer 3 = Change = Enabled = Count Up
Output 0 Glycol Chiller Ramp Primary Temp to 70 over 3 Days
Output 1 Glycol Valves Ramp Primary Temp to 70 over 3 Days
Exit 0 = Temp 1 => 70 goTo State 2
Exit 1 = DIN 1 (Step 2) = On goTo State 2
(Exit 1 : This is a Manual Toggle Switch(Din 1) that I want to automate)
Alarm = None

State 2 = Maintain Primary Temp @ 70 for 3 Days (Diacetyl Rest)
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary
Timer 2 = Diacetyl = Enabled = Count Up
Timer 3 = Change
Output 0 Glycol Chiller Ramp Primary Temp to 70 over 3 Days
Output 1 Glycol Valves Ramp Primary Temp to 70 over 3 Days
Exit 0 = Timer 3 Diacetyl => 72:00:00 goTo State 3
Exit 1 = DIN 2 (Step 3) = On goTo State 3
(Exit 1 : This is a Manual Toggle Switch(Din 2) that I want to automate)
Alarm = None

State 3 = Ramp Primary Temp down to 54 over 3 Days
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary
Timer 2 = Diacetyl
Timer 3 = Change = Enabled = Count Up
Output 0 Glycol Chiller Ramp Primary Temp to 54 over 3 Days
Output 1 Glycol Valves Ramp Primary Temp to 54 over 3 Days
Exit 0 = Temp 1 => 54 goTo State 4
Exit 1 = DIN 3 (Step 4) = On goTo State 4
(Exit 1 : This is a Manual Toggle Switch(Din 3) that I want to automate)
Alarm = None

State 4 = Maintain Primary Temp @ 54 for 12 Days
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary = Enabled = Count Up
Timer 2 = Diacetyl
Timer 3 = Change
Output 0 Glycol Chiller Maintain Primary Temp @ 54
Output 1 Glycol Valves Maintain Primary Temp @ 54
Exit 0 = Timer 1 Primary => 72:00:00 goTo State 5
Exit 1 = DIN 4 (Step 5) = On goTo State 5
(Exit 1 : This is a Manual Toggle Switch(Din 4) that I want to automate)
Alarm = Loop
State 5 = Maintain Primary Temp @ 54 Check SG for 1 Day
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary = Enabled = Count Up = Continue
Timer 2 = Diacetyl
Timer 3 = Change = Enabled = Count Up
Output 0 Glycol Chiller Maintain Primary Temp @ 54
Output 1 Glycol Valves Maintain Primary Temp @ 54
Exit 0 = Timer 3 Change => 24:00:00 goTo State 6
Alarm = Loop

State 6 = Maintain Primary Temp @ 54 Check SG for 1 Day
Timer 0 = Fermentation = Enabled = Count Up = Continue
Timer 1 = Primary = Enabled = Count Up = Continue
Timer 2 = Diacetyl
Timer 3 = Change = Enabled = Count Up
Output 0 Glycol Chiller Maintain Primary Temp @ 54
Output 1 Glycol Valves Maintain Primary Temp @ 54
Exit 0 = Timer 3 Change => 24:00:00 goTo State 5
Alarm = Loop
BrunDog
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Re: Self Latching Relay

Post by BrunDog »

As you noted, use a latching relay. It will require two outputs on the BCS: one to latch and one to reset. The trick is to note that the BCS outputs can only drive a few milliamps, and the relay you are designing in will have a contact rating (that must exceed the circuit power you are switching downstream) and a coil rating. Should the coil rating exceed those few milliamps, you will need an intermediate "amplifier" aka solid state switch aka SSR aka transistor circuit.

There are solid state latching relays also available, but again you need to pick the one which will appropriately power your downstream circuitry.
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

What I am trying to do is close the DIN. If I am away and something happens to the fermentor like a power Outage or a wrong click, the fermentor will go back to its correct state with the DINs as an exit condition.

On the latching Relay:
BCS 5 vdc + to one side of LOAD. Other Side Load to DIN 0.

I would like a board with at least 4 latching relays that have a built in trigger. I am not sure if this on would work:

http://www.amazon.com/SMAKN%C2%AE-6-Cha ... ge_o04_s00


No Instuction that I can find.

Until I get the relay knowlwge and board, I am wiring with Toggle switches but running the Relay Control wiring as well.

When relay is closed, DIN 0 is closed. Because it is latching, it stays closed without power. I have lots of Outs that are not used on the Fermentor BCS 462. I have not got it setup yet but plan:



Out 0 = 110vac 25a SSR = Glycol Chiller
Out 1 = 110vac 25a SSR = Glycol Pump
Out 3 = DC 10a SSR = Glycol Upper Valve
Out 4 = DC 10a SSR Glycol Lower Valve
Out 5 = 110vac 25a SSR = Freezer 2
Out 6 = 110vac 25a SSR = Freezer 3
Out 7 = 110vac 25a SSR = Freezer 4
Out 8 = DIN 0 DC 10a SSR = Eight Day
Out 9 = DIN 1 DC 10a SSR = Diacytel UP
Out 10 = DIN 2 DC 10a SSR= Diacytel Rest
Out 11 = DIN 3 DC 10a SSR = Diacytel Down
OUT 12 = DIN Relay Reset DC 10a SSR
Out 13 = Free
Out 14 = Free
Out 15 = Free
Out 16 = Free
Out 17 = Free

I may use the Free OUTs and DINs and run them to my Brew side and use them with Valves and Floats to fill vessels as I am running out of free items on my Brewside BCS 462
BrunDog
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Re: Self Latching Relay

Post by BrunDog »

OK, now I have no idea what you are trying to do. You are trying to latch an input to the BCS?
JonW
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Re: Self Latching Relay

Post by JonW »

If you have a computer that runs 24x7, you could use wget or curl to fire off some BCS API commands at set times to ensure your process/state was where it needed to be. No hardware required and no loss of inputs/outputs.
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

BrunDog wrote:OK, now I have no idea what you are trying to do. You are trying to latch an input to the BCS?
I am trying to make sure than some DINs are latched on automatically.

Basically as each state is finished, it fires the latching relay. The relay "load" is the BCS 5 vdc and the other leg a DIN.

Once a state is complete, the DIN is set as an Exit Condition as well as the original reason to exit.


Basically for lager fermentation. Once a State is complete, it will not repeat.


I got to thinking about this from another thread about locking a State. I travel and plan to monitor my lager fermentation while away. I want it to basically be somewhat automated as Murphy says the wrong thing will be done most ofte
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

JonW wrote:If you have a computer that runs 24x7, you could use wget or curl to fire off some BCS API commands at set times to ensure your process/state was where it needed to be. No hardware required and no loss of inputs/outputs.
Not sure how using wget or cUrl would be much different than relying on the BCS itself. I do have it on a battery backup. I am wanting a physical switch in case of an extended power outage or I hit ALL Stop by accident when I am in Egypt or some other far flung place. I connect via Port Forwartding to monitor the processes and actually got to thinking about this from the post about locking a State.
http://forum.embeddedcc.com/viewtopic.php?f=6&t=2838
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Re: Self Latching Relay

Post by JonW »

oakbarn wrote:Not sure how using wget or cUrl would be much different than relying on the BCS itself. I do have it on a battery backup. I am wanting a physical switch in case of an extended power outage or I hit ALL Stop by accident when I am in Egypt or some other far flung place. I connect via Port Forwartding to monitor the processes and actually got to thinking about this from the post about locking a State.
http://forum.embeddedcc.com/viewtopic.php?f=6&t=2838
Sorry, guess I could have explained that in more detail. You can setup CRON or Windows scheduler to run jobs at certain times or intervals and they can also be set to be "made up" should the power be out. For example, you could setup a CRON job to fire every 30 minutes to start your process and assert state 0 for your initial 8 days, then have another CRON job that fires every 30 minutes for 3 days asserting state 1, etc. etc. etc. With several CRON jobs, you could ensure that they continue to fire and set your required states for whatever time period you required. You wouldn't really need the repeating every 30 minutes, but I added that as it would help you if you hit all stop by accident.
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

I actually set up a Process that will Start my "Lager Process" at State 0 if it is not running. It comes on even if the Power is lost or All Stop is clicked. I use Ladder Logic for that by putting just the "Cycle" Process in the Coil of a Ladder Step. The Cycle is ALWAYS on when the BCS is on. It has only a Couple of Steps. I ASSERT the "Lager Process" on exit of State 0 of the Cycle Process. Ot JUmps to State 1 which Exits back to State 0. I have set it to show NEVER but you cannot turn it off if you try as the Laddder Logic will just restart it immediately. I have the Extra DINs as the BCS is used just for fermentation. I normally take my computer so I would need one to use as an "extra timer". I am hoping to find the "latching telay" that will be a physical as well as non expensive soultion.
clearwaterbrewer
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Re: Self Latching Relay

Post by clearwaterbrewer »

latching like this?

http://www.ebay.com/itm/201209912990

if so, you should be flogged for not browsing all of electonic-salon's product on eBay ;-)
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