Self Latching Relay

Discussion of the physical aspects
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

I guess I need flogging! I ordered one. I think the trigger is 5 vdc at 119 ma so the BCS should be able to do that without a relay?
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Re: Self Latching Relay

Post by JonW »

oakbarn wrote:I guess I need flogging! I ordered one. I think the trigger is 5 vdc at 119 ma so the BCS should be able to do that without a relay?
If they are 119 mA, then they are way over the output of the BCS. Each BCS output is only rated at 20 mA.
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

Thanks for the quick response. I have a extra DC SSR. I guess I will need a 5 vdc power supply as well to use this one or buy a 12 vdc one.
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Re: Self Latching Relay

Post by clearwaterbrewer »

now I feel bad... I found they have a better one for the BCS 50ma draw ( I think that is from the power supply, and the S/RS signal is just a 1mS-1S pulse

should look at http://www.ebay.com/itm/131608618526
and 12V version - http://www.ebay.com/itm/371444992995
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Re: Self Latching Relay

Post by oakbarn »

I purchased a DIN Rail Mount Passive Bistable/Latching 4 DPDT 8A Power Relay Module, 12V Ver that has 4 different latching relays.

I will use an Out for each Relay to Unlatch but just have a toggled 12 vdc to latch all of them at the same time.

I will set the Process State to Exit on Din = Off

I will have the DIN Circuit on the load side.

This is a simplified drawing of my plan. May change once I get the physical board but I think I have it correct. I am not an electrical engineer so the drawing may not be correct! :D
Latching relay Plan.png
Latching relay Plan.png (85.73 KiB) Viewed 10222 times
JonW
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Re: Self Latching Relay

Post by JonW »

It looks like you're powering those relays from the BCS 5V supply. What is the current draw on them? Remember, the BCS does not power devices, it only triggers them!
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Re: Self Latching Relay

Post by clearwaterbrewer »

Agree, you should get the 12V latchign relay board and wire to your 12v supply!
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Re: Self Latching Relay

Post by oakbarn »

I am using DC SSRs to trigger the relays with 12 vdc. The Relays are triggered by the BCS 5 vdc Out and the SSRs when asserted send 12 vdc to the relay board. The Load side of the SSRs are 12 vdc and the trigger side of the SSR is from the BCS. The load side of the Latching Relay has the 5 vdc from the BCS and sends it to the Din on the BCS when the Latching Relay is triggered.

So


DC SSRs triggered by Out on BCS (Nominal 5 vdc as any other SSR using BCS as Trigger)

Latching Relay Triggered by 12 vdc from Load Side of DC SSR when Out is Asserted.

DIN Triggered by Load side of Latching Relay from 5 vdc from BCS.


Only the SSR and the DIN are using the 5 vdc from the BCS.

Of Course this takes 4 Outs from the BCS but I have a BCS just for Fermentation. I have not got it totally setup but am very close. I have made my "DIY" Chiller and have all the "parts" to complete my Controlled Fermentation using the Jacketed Conical. I hope to do my first trial in June!
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oakbarn
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Re: Self Latching Relay

Post by oakbarn »

I purchased This off ebay and finally got it wired to the BCS but I am not sure if I have it right as it is not doing what I want. :oops:

http://www.ebay.com/itm/DIN-Rail-Mount- ... xyrrpTjZUJ

Her is a pix of how I have it wired:
Bistable_Question.png
Bistable_Question.png (47.41 KiB) Viewed 9932 times
There is no Ground on the Relay that I can see, It seems like the Relay is a Pull down Resistor type but it is not pulling and latching like I thought. Is my wiring correct?

I have tried to contact the seller and have gotten responses, but we are in different worlds. :D
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Re: Self Latching Relay

Post by JonW »

From the looks of it, you need a negative trigger for the latching relays. Their schematic (from the ebay link) shows V+ power and S/R inputs - which should be negative. Your drawing shows feeding 12V positive to both inputs.
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