Circuitry of Alarm Panel Outputs and Inputs

[james.wilson]

no in this case it allows the panel to detect if the wire is attacked and someone tries to defeat the sab tamper by shorting to 0v. You need a panel that supports this feature

[Eugene's DIY Den]

4 hours ago, james.wilson said:

no in this case it allows the panel to detect if the wire is attacked and someone tries to defeat the sab tamper by shorting to 0v. You need a panel that supports this feature

On my new sounder, if tamper return from the panel is connected to NC, the bottom of the 4.7k resistor (attached externally to the terminals) is either grounded when the transistor is on, or floating when it's off, depending on the state of the tamper switch in the sounder. So the resistor is either connected in parallel with the tamper lines, not connected, or the third state is someone has defeated the tamper by puling the line to 0v. Is 4.7k (or whatever resistance) the normal resistance for no alarm to occur, and then either a short between lines or the resistor floating with the transistor off, the two conditions which trigger an alarm?

[Eugene's DIY Den]

Ok, I think I'm beginning to make sense of these EOL resistors. I'm guessing the EOL resistor is the bottom resistor of a potential divider, the other resistor  is in the control panel. The panel detects 0volts, high volts 5v? and a reduced voltage, Possibly half voltage when everything is ok?

 

So there are three scenarios:

1) Zone wiring is shorted by burglar or fault, producing 0 volts at the panel

 

2) Wiring goes oc due to a sensor being triggered, a cut wire, loose connection or whatever. This produces a high voltage at panel

 

3) Normal conditions - EOL resistor plus series resistance of loop. Panel detects an intermediate voltage.

 

On my SCB, when its tamper switch is closed, the transistor is on, pulling the EOL resistor down to ground. When the tamper switch operates, the transistor opens and the end of the resistor floats so it's taken out of circuit.

 

 

 

 

[james.wilson]

2 hours ago, Eugene's DIY Den said:

Ok, I think I'm beginning to make sense of these EOL resistors. I'm guessing the EOL resistor is the bottom resistor of a potential divider, the other resistor  is in the control panel. The panel detects 0volts, high volts 5v? and a reduced voltage, Possibly half voltage when everything is ok?

 

So there are three scenarios:

1) Zone wiring is shorted by burglar or fault, producing 0 volts at the panel

 

2) Wiring goes oc due to a sensor being triggered, a cut wire, loose connection or whatever. This produces a high voltage at panel

 

3) Normal conditions - EOL resistor plus series resistance of loop. Panel detects an intermediate voltage.

 

On my SCB, when its tamper switch is closed, the transistor is on, pulling the EOL resistor down to ground. When the tamper switch operates, the transistor opens and the end of the resistor floats so it's taken out of circuit.

 

 

 

 

yes

 

[Eugene's DIY Den]

Sounder now on wall and working fine. Pity the strobe on the HKC sounder (3 so called 'high intensity" LEDs) is so crappy. The xenon tube on my old sounder was much more effective. Maybe it'll be better when it's dark.
Thanks for the help everyone!

 

 

 

 

[james.wilson]

6 minutes ago, Eugene's DIY Den said:

Sounder now on wall and working fine. Pity the strobe on the HKC sounder (3 so called 'high intensity" LEDs) is so crappy. The xenon tube on my old sounder was much more effective. Maybe it'll be better when it's dark.
Thanks for the help everyone!

 

 

 

 

agreed a xenon looks better

[al-yeti]

12 hours ago, Eugene's DIY Den said:

Sounder now on wall and working fine. Pity the strobe on the HKC sounder (3 so called 'high intensity" LEDs) is so crappy. The xenon tube on my old sounder was much more effective. Maybe it'll be better when it's dark.
Thanks for the help everyone!

 

 

 

 

White leds show up good in the day though...

[datadiffusion]

The 'new' (prob at least 18 months ago now) Elmdene Quartz LED strobe is pretty good tbh, this is an upgrade in an existing housing that used to be strobe.

 

I actually had a 'crazy' one once, not sure if it was an overgassed tube or what, but even in the daytime it lit up half the house like a halo, no kidding. Still works at every service though.

Have to get a vid it's so odd to see.

[al-yeti]

45 minutes ago, datadiffusion said:

The 'new' (prob at least 18 months ago now) Elmdene Quartz LED strobe is pretty good tbh, this is an upgrade in an existing housing that used to be strobe.

 

I actually had a 'crazy' one once, not sure if it was an overgassed tube or what, but even in the daytime it lit up half the house like a halo, no kidding. Still works at every service though.

Have to get a vid it's so odd to see.

You load to much plutonium?

[datadiffusion]

It actually pretty much does look like an excursion it's so bright!