Problem - Open Collector output to a negative trigger relay not working

[Desert_AIP]

RAL
I put the wires back the way I originally had them, as you describe.
Negative power to NEG, OUT to low trigger input.
 
In the static (off) mode.
12VDC power
1VDC between +DC and negative trigger
11VDC between negative trigger and -DC/GND
 
With the button jumpered (on).
 
0.7VDC between the negative trigger input and -DC/GND.
11VDC between the negative input trigger and +DC.
 
The doorbell is triggering and the solenoid is buzzing (activated) with the button jumpered.
But the relay is not triggering.
If I jumper -DC to the trigger it does.
Do you think I have to take it all the way to GND?
 
I removed all the diodes for now.

 

[RAL]

Ok, great information!  With the doorbell button jumpered, the 0.7V between the negative trigger input and -DC/GND is just what I expected.  So that tells us that the open collector transistor is doing exactly what it is supposed to do.
 
My guess is that the relay board needs to see a voltage that is less than 0.7V in order to trigger the relay. 
 
Next, I would try adding the diode back in between the relay board -DC/GND terminal and the power supply -DC/GND terminal.  Make sure you leave the 930's NEG terminal connected directly to the power supply -DC/GND terminal.  You don't want to connect the 930 NEG terminal through the diode.
 
Then, repeat the measurements using the power supply -DC/GND terminal as your reference point.

 

[Desert_AIP]

Static
11.37VDC supply
-0.7VDC between -DC/GND and NEG terminal of 930
10.3VDC between -DC/GND and negative trigger pin
 
Jumpered
55mV between -DC/GND and negative trigger, does not activate.
Place a jumper wire from NEG terminal to OUT terminal, activates (goes to -0.7V).
 
This is getting frustrating. 

 

[RAL]

It's hard to figure what's going on here.  By any chance was a schematic included with the relay board?  That might help figure things out. 
 
I'm guessing at how the 555 timer on the board is wired, but for the function this board is supposed to do, it seems like it would be set up for monostable operation.  As such, the trigger input on the 555 chip should trigger it when the voltage drops below 1/3 of the power supply voltage.  But it's not clear that this is connected directly to the negative trigger input terminal of the relay board, which might explain why it doesn't trigger even though the trigger voltage to the board is well below the 1/3 point.
 
Just to double check - you do have DIP switch 2 set to ON and 1 and 3 set to OFF for negative triggering, right?

 

[Desert_AIP]

Yes. it's set up correctly.
I've used this board three times now.
It is a simple 555 monostable.
 
The thing that really has me stumped is it triggers fine when I give it a 0 volt input either from the supply terminal or I bridge the negative and negative trigger terminals.
The OC transistor is working correctly, but its not triggering the board.
 
I'm wondering if the cap is holding the pin high.
But I don't think so because I just metered it at 55mV.
 
In the morning I'm going to try to get the OC to trigger a standard relay, I know the relay will operate the time delay correctly via dry contacts.
That adds another component and is starting to look kludgy.

 

[pete_c]

I am curious what you see after all of this.
 
My source 12VDC comes from the OPII panel such that I used cat5e (70 feet?) to the Elk 930/960 board. 
 
Pairs utilized for the 12VDC and single wires for the zone switch.
 
Negative of the OPII 12VDC goes to the Elk 930 along with a 12VDC negative to the Elk 960 (with the diode in place).
 
Relating to my "el cheapo" debounce board I bench tested it doing all sorts of things with it before putting it into place.
 
Here is a picture.
 

 

[BraveSirRobbin]

Do you have documentation on your one-shot?
 
I think that RAL's initial assumption is correct in that you are never getting a true 'zero' compliance sufficient to trigger this unit.  A variable DC supply to the trigger could test this.
 
If this were me though, considering the time you spent on this, I would just get an Elk-960 or better yet, since you are still using the original doorbell unit, just put a door contact sensor near the coil of that solenoid (the dinger's coil) and have that provide a contact closure (a few articles on how to do this here on CT).  I've been using this method for years to trigger a DS10a.

 

[Desert_AIP]

BraveSirRobin, the only docs are in the e-bay ad.
As Pete said, el cheapo.
 
My concern is if I swap in an Elk 960 I'll get the same result.
 
Pete, thanks for the pic.
I have mine wired the same as yours with one exception.
I'm not using 12VDC from the Omni.
I have a small 24VAC to 12VDC voltage converter hooked up to the doorbell transformer to power the relay board.
I don't think that's the problem, even when the transformer is under load from the doorbell solenoid the 12VDC voltage readings are still stable.
 
I'll step back from it and come back to it.
Now it's a puzzle I have to solve, challenge accepted! 

 

[BraveSirRobbin]

I have a small 24VAC to 12VDC voltage converter hooked up to the doorbell transformer to power the relay board.

The 960 is proven to work with the 930, Elk even provide a schematic on how to connect them both (Pete referenced it in a previous post in this thread),
 
Your statement above is concerning.  Can you power the board with just a 12 volt wall wart?  I fear you might have a reference problem.
 
A schematic (just hand drawn) would also go a long way here (with everything listed, power supplies, adapters, diodes, etc...) that would hopefully help as well.

 

[Desert_AIP]

Here is the AC/DC voltage converter I'm using.
 http://images.monstermarketplace.com/video-security-systems/ac-dc2412-1-5-24vac-to-12vdc-converter-300x174.jpg

http://www.ebay.com/itm/Power-Supply-Voltage-Converter-24VAC-to-12VDC-1-5-A/251430423283?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3D12bf028e6834430d9c3178ec60343f64%26pid%3D100005%26prg%3D20131003132420%26rk%3D4%26rkt%3D6%26sd%3D261093261130&rt=nc

I don't see how reference could be a problem.
The board power and trigger power are coming from the same source.
The 12VDC is rock steady, even when the transformer is under load.
 
Here is my diagram.
It's the same as pete's except for the board type and power source.
 http://i175.photobucket.com/albums/w135/Desert_AIP/Doorbell_Board.png

To reiterate.
The 930 transistor works.
The relay board operates when the negative power pin (with or without the diode) is shorted to the negative trigger pin.
The relay properly operates the Omni zone.
The relay board does not trigger by the negative power routed through the 930, even though the voltages appear to be correct.
 
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[Desert_AIP]

I just hooked up an Elk 912 relay between the 930 and the delayed relay board.
The output of the 930 triggers the 912 as expected and the dry contacts of the 912 trigger the delay board.
So it works as I expect.
 
For some reason the 930 OC output doesn't trigger this cheapie board, but I have no idea why.
I NEED TO KNOW WHY!!!   :nutz:
 

I'll probably get a 960 and swap it in, although I still worry it won't work.

 

[Desert_AIP]

Now - I - am - going - to - have - a - beer...
 
Just for giggles, I removed the relay and wired it back the way I originally had it, as in pete's diagram.
Then I swapped the wires from the OC to the relay board.
I have the negative power pin connected to the 930 OUT pin and the 930 NEG pin to the negative trigger.
Pressed the button...it works!
 
In all my wire swapping I must not have tried that config.

 

[RAL]

Just for giggles, I removed the relay and wired it back the way I originally had it, as in pete's diagram.
Then I swapped the wires from the OC to the relay board.

 
Late last night, that same idea of swapping the wires from the OC output occurred to me.  But then I thought, "Nah... that won't do anything. The NEG terminal on the 930 is labeled that way for a reason."   I'm glad you tried it and it worked!

 

[RAL]

Just two more questions... what voltage do you now see at the negative trigger input pin?  Do you still have the diode in the circuit? 

 

[Desert_AIP]

Fail -  it's operating intermittently. 
 
I'll meter it and see what is going on.