SW-1070 External Bell Not Sounding

[james.wilson]

It's an output. Get your meter out and see if it fires. 

[Eugene's DIY Den]

9 hours ago, al-yeti said:

No but jw means did you change the output for bell to do something else , or change its trigger so it will never trigger 

Not delibarately, but it's possible. Where is this in the menu? If you mean a physical terminal, not a logical output, no I didn"t change it. Do we know which terminal the panel pulls low when it tests the bell? Bell hold-off or Ext bell minus? That test sounds the bell.

Edited February 29, 2020 by Eugene's DIY Den

[al-yeti]

R u using  blocks?

[Eugene's DIY Den]

4 minutes ago, al-yeti said:

R u using  blocks?

No.

Just repeating reply above, (edit timed out out and I couldn't save)

Not delibarately, but it's possible. Where is this in the menu? If you mean a physical terminal, not a logical output, no I didn"t change it. Do we know which terminal the panel pulls low when it tests the bell? Bell hold-off or Ext bell minus? That test sounds the bell.

If the bell is sounded by one of the outputs being pulled low, a broken core in cable would explain why its not working. However if the output is normally held low and floating it triggers the alarm, a break wouldn't cause a trigger. I still dont understand how the circuit works. If I could see a schematic I would understand what to expevt with a meter.

 

 

Edited February 29, 2020 by Eugene's DIY Den

[james.wilson]

By default its the ext Bell - terminal but it is programmable as anything so if changed won't work as a bell

But it 'could' be a broken core or knackered bell

[Eugene's DIY Den]

As I understand it from this schematic, SAAB hold on the panel is the power ground for the bell, it's marked 0v on both panel and bell. So if the core from the panel to the bell was broken, the bell wouldn't even be powered. (Maybe it isn't, the LEDs are lit, but I need to check if they are powered separately from the strobe inputs). There's an open collector NPN transistor connected to external bell minus on the panel. Is this driven on in an alarm condition, pulling the external bell minus input on the bell low? Or is it on and turned off when there's an alarm?

Sorry for all the questions, but I want to understand how the thing works before I start measuring voltages and doing continuity checks ☺

Edited February 29, 2020 by Eugene's DIY Den

[Eugene's DIY Den]

Update! Checked voltage between ext. bell + and - on panel and it was 0v. Activated alarm after arming by releasing tamper spring on panel. Bell sounded. Checked same voltages. 12 v this time so ext. bell - on panel must be going low, activating trig - on bell.

[Eugene's DIY Den]

Further update! Triggered alarm again. Internal sounder activated. Waited to see what happened. This time the external bell sounded  about 20 seconds after internal sounder. Checked bell delay in settings and it was zero. Edited it again and changed to 0 and resaved and this seemed to sort the problem. Setting in RAM must have got corrupted, but the delay should have affected both bell and sounders. Very confusing.

[al-yeti]

4 minutes ago, Eugene's DIY Den said:

Further update! Triggered alarm again. Internal sounder activated. Waited to see what happened. This time the external bell sounded  about 20 seconds after internal sounder. Checked bell delay in settings and it was zero. Edited it again and changed to 0 and resaved and this seemed to sort the problem. Setting in RAM must have got corrupted, but the delay should have affected both bell and sounders. Very confusing.

So you didn't wait for the external bell to sound

 

Never had this issue personally , but yes you probably got confused at some point I agree with that

 

Good your fixed

 

Now can we book you Uber taxi to holiday Inn on bath road Heathrow?

[Eugene's DIY Den]

Still another bit of the saga left! This time I used a stopwatch. When I trigger the alarm using an entry door, and let the countdown timeout without disarming with a code, the bell sounds 30 seconds after the internal sounder (I thought changing the delay setting made a difference, but it didn't). When I trigger by opening an alarmed internal door, the bell sounds immediately, followed by the internal sounder a couple of seconds later. So I guess this 30 second delay is by design to allow a user to cope with the alarm going off and disable it when they hear the sounder inside if they exceed the timeout?

Edited February 29, 2020 by Eugene's DIY Den