DS10a & Elk-930

[jrfuda]

Gang,

Has anyone successfuly interfaced a DS10a with an Elk-930 ? I thought it would work, but it does not.... the DS10a just blinks about every 30 seconds and sends out a "normal." Pressing the test button makes it send out an "alert" but ringing the doorbell with it wired per the instructions (output pair to the automation controller - in this case, ds10a, and the input pair spliced between the transformer and transformer connection on the bell) and does not work.

Any idea how to get this to work?

Thanks,

[rocco]

John, try swapping the two wires between the Elk-930 and the DS10A. I know the Elk has a particular polarity, and the DS10A may be sensitive to polarity (I know the PowerFlash is).

[BraveSirRobbin]

John:

Looking at the instructions for the 930 shows that it is an open collector output and NOT a contact closure. Therefore connecting the 930 directly to the DS10A may not work.

I'm not sure what would be the best methodology here as also looking at the manual it states:

"The ELK-930 output follows the ringing pulses (approx 25hz). To filter these pulses into a steady output, an ELK-960 can be connected to the ELK-930(C) to get a timed relay output".

So I "think" what they are saying is that even if you get the open collector to trigger a plain relay, it still might not register with the DS10A. The ELK-960 on the other hand, can detect very fast pulses which will "trigger" a timing circuit on the board and close a set of contacts on the on-board relay for whatever the user sets this interval for (say a few seconds). This contact closure could then be easily detected with the DS10A.

Other's may have a better opinion!

EDIT: I see rocco gave a suggestion while I was typing this response, worth a shot. Rocco, what do you think about maybe a 2.2K pull up resistor and a capacitor?!?!

[rocco]

BSR, I'm not sure, but I think the bit about the pulsing refers to using the Elk for telephone ring detector, not a doorbell. I think he may be fine for a doorbell. Don't know for sure . . .

The open-collector output means that it will act as a uni-directional contact. Assuming that the DS10A uses a small DC voltage through the contact, the polarity would need to be correct. Also, the voltage would have to be greater than the diode-drop across the open-collector output, meaning greater than .7 volts.

I don't have any DS10As, so I can't measure the voltage across the contacts. Maybe someone else can (with no contacts attached, of course).

[BraveSirRobbin]

Ah, my mistake, you are correct in the fact that I was reading "telephone ring detect". Either way if this doesn't work you could go with the timer relay. I'm using one directly for my dryer monitor as the finished buzzer was to fast for my SECU16I to detect. It's a nice unit although a little on the pricey side and requires an external DC voltage supply.

[jrfuda]

I'll try swapping the wires around.. I though I had already tried that, but since both leads coming out of the DS10a are the same color, I may have not actually swapped them, but rather put them back the way I had them the first time.

I had always assumed that what would work with a powerflash would work with a DS10a, but maybe not. I'll give it another try tonight.

rocco, I have a multimeter so I should be able to test the voltage across the contacts, I'll see what it is.

BSR, would the the timer unit be used by itself, or in conjunction with the 930? I wonder If I could power it off of the doorbell transformer (I'd have to see if it's 12VDC) to negate having to run power, which given the chime's non-proximity to any AC outlets would make this a no-go.

Also, let me see if I understand.... When the 930 sees a ring, it causes the voltage across the contacts to drop. Would wiring a resistor inline with the contacts do anything to help with this? Everything I know about electronics I've learned from y'all, so I'm still learning.