SC12A with OnAler AHP: ARM & DisARM cmd

[dave w]

I tried that too, but it didnt work either. As it's only produces ~4.47v accross when it's armed, and 0V when not.
Powerflash requires at least 6v, or close contact.

4.5 V should be enough to trigger a sensitive relay, and use N.O. contacts to trigger Power Flash in dry contact mode.

http://www.allelectronics.com/make-a-store/item/RLY-495/5-VDC-DIP-REED-RELAY/1.html

http://www.allelectronics.com/make-a-store/item/RLY-541/5-VDC-SPST-N.O.-DIP-REED-RELAY/1.html

http://www.allelectronics.com/make-a-store/item/RLY-528/3-VDC-DPDT-MINIATURE-RELAY/1.html

http://www.allelectronics.com/make-a-store/item/RLY-532/5-VDC-DPDT-MINI-SIGNAL-RELAY-2A/1.html
etc.

[phongluu]

Thanks dave w, again... all inputs are appreciated. I'm gonna try one at the time...

As I did try with the 5 VDC relay DPDT as in your last link: it couldnt do it, as the current is too little, while the relay needs few hundred mA.
I think the LED current is around 20mA?

I'm gonna read on the first 3 relays that you post there. Thanks.

I may have to hit google with somehow comeup with small circuit to detect this low current LED on....

P.L

[Knightrider]

google "opto-coupler" or "opto-isolator"

[phongluu]

Thanks a lot. 
That sounds great!
I'm gonna try that and be back here with result.
Do you know if pin 1&2 of optocouple draws to much current, when it's mounted parallel with armed LED?
Shouldn't be ....
Hmm....I'll experience it.
Thanks again,
P.L

[Brian H]

Most optocouplers have a LED in them and require a current limiting resistor also be used. In series with pin 1 or 2.

Connecting 1 and 2 across the consoles LED would use the current limiting resistor of the console LED. Depending on the exact optocoupler used. The consoles LED maybe dim as the total current now is split between the original LED and the optocouplers input.

Also remember. The Powerflash in the dry contact mode has an internally generated voltage on the input contacts.
On mine the terminal market + is actually - when in the dry contact mode.
So the solid state output on the optocoupler would need to have the correct polarity on its connections.
I ran into this when I connected an ELK Doorbell Current Sensor to a Powerflash. It used a optocoupler for its output.

[Knightrider]

I was thinking that you could just remove the LED on the SC1200, and use the whole voltage to drive the opto.  If there's a powerflash involved, another means of notification would always be present.  i.e. Dave_X10_L's table top lantern that monitors the garage door.

[dave w]

phongluu
The very first relay has a coil resistance of 350 ohm. That would get you down to 14 ma at 5V, which might trigger the relay if the coil took the place of the LED. Or if you could identify the current limit resister for that LED you might be able to connect one side of the relay to the input side of the resister and to the "return" side of the LED (?).

The opto isolator is a great idea too, if the dry contact mode of the Power Flash has enough potential to get conduction through the opto's output transistor(?).

I want to try the cadmium sulfide cell trick with a Power Flash, but just haven't got to Radio Shark to get the cells. I don't know if a LED will drop the Cds cell resistance enough to trigger the Power Flash.

[Brian H]

I did some tests with a Powerflash module and some optocouplers.

All I had in my stash of parts where 4N31 and 4N33 NPN Darlington output chips. So I could not try the 4N25-4N28 NPN transistor types.

All of the 4N33 and 4N31 chips pulled the Powerflash outputs to .25 volts with around 4 ma of input current and it triggered fine. Raising the input current to 10 ma and the output was like 50-100 mv depending on individual chips.

Only thing I saw on one of the test chips was the output was slightly On at 5.95 volts from the 6.1 volts completely open. Had to add a 100K resistor from the outputs base pin to emitter pin. Must have had enough gain to slightly turn on.

[Brian H]

I have a few optocouplers with NPN transistor outputs on order and will try them with a Powerflash. When they arrive.

[phongluu]

I'm ordering few octocouples today...

On other note, I found these old posts, I can learn something from them:
http://forums.x10.com/index.php?topic=12761.0
http://forums.x10.com/index.php?topic=18016.0

yet, I'd like to do something as just simple as with octocouples and powerfash

I'll be back with some results...


Thansk all.

[Brian H]

Keep us in the loop on how they work for you.
I have a few with NPN transistor outputs on order myself.
I have tried ones with NPN Darlington transistor outputs and they did work with a Powerflash.

[phongluu]

Yes, I sure will be back with results.

On the note of NPN transistor, I beleive it should make the powerflash trigger. However, I still haven't thought of a way to connnect to the armed LED of SC12A: both legs are measured 5v, one drops to 3v when it's armed.

P.L

[phongluu]

Ok. Results:
1. I have tried all options for nothing! All type of relays, transistors, opamp, optocouplers = nothing seem can trigger the powerflash that AHP can register.
      . As small relay with as low as 10mA, 5v
      . Optocoupler

After the optocoupler not working, I start thinking...something definitely not right here, as I bench test it and it trigger the powerflash perfectly. Why not with SC12A LED armed....?!

Then I discOver that while arming SC12A sending out HC On/Of cmd that blocks EVERYTHING at that moment!

2. Now, after I filter the SC12A PS and just simply connect the powerflash to the LED = working perfectly!

I will upload a pix later to show where to get 4.7v when arming success (passing the dropping resistor)

Dawn this SC12A!

[phongluu]

More data:

So with SC12A PS filtered:
1. Arming on the console, it triggers the powerflash fine with just connect to the LED (no relay, no optocouplers, no etc...)
2. Arming on the Remote or OnAlert: it does not trigger the powertflash that connects to the LED as same as in (1)! WTH!
3. DisArming on console or on remote or OnAlert: it triggers the powerflash just fine.


I wish x10 documented it somewhere how exactly this thing works.
That reminds me how the DS7000 act diff when arming with remote, OnAlert

DS7000: remote arm: HC ON, then OFF (if success); OnAlert: HC ON!
x10, AHP sometime drive me nut

P.L

[Brian H]

Yes when armed home from the console. It does send out the two lights codes On. Then an Off about one second later.

In arm away from the console. It sends the On, Exit delay times out and sends the Off.

The Keyfob is Arm Away with no delay. The consoles manual briefly touches on the no delay thing.

Supposed to be a visual indication of the armed activation.

Since both the Powerflash and Console are not polite. They will step on each other.

One thing to think about. If you filter the consoles power supply. It will no longer flash the lights or trigger a Powerhorn Siren on an alarm.