Project Help

[mattylad]

every part of this needs to be able to silence the alarm.

What do you mean by this?

 

[Spark123]

I imagine he wants to be able to silence (or accept) the alarm buzzer without it inhibiting the function of the buzzer to the other two alarms??
Not got enough time now, will have a better look later.

 

[mattylad]

I'm still not following that?

If the buzzer is off any circuit will make it sound.
If it is on no other circuits will make it sound, once it has been reset then any circuit will make it sound.

If it needs to be more complicated then IMO a fuller explanation of what and how needs to be detailed.

We could be moving into the territory of using more logic, perhaps a PIC to simplify the component list.

 

[mattylad]

How about this then, this includes an accept/buzzer silence button that leaves the LED on and any further inputs will also sound the buzzer.

The whole lot reset by a biased keyswitch so any old twonk cannot reset it.

3 WAY ALARM WITH BUZZER SILENCE

• mattylad
• 8 Jan 2012
• 1

BUZZER TO SILENCE ALARM, BIASED KEYSWITCH TO RESET WHOLE ALARM.

This is getting more costly is there a budget?

It could all be build on Veroboard or would you prefer (and pay for) a proper PCB? a PCB may cost £30 on its own. Components are about £20-30 (not including the box).

 

[wreck-it-steve]

Here is how i need it to work:

There are three aux contacts, if any of the three close (on fault) then the alarm will sound and in turn light the apropriate LED lamp. I need to be able to silence the alarm until the contact is back in its normal state.

Thanks

 

[mattylad]

DOH! ignore that, the led will relatch the relay.
SO if you need to silence the alarm until the contact is in its normal state then brb.

 

[mattylad]

Does the LED need to still light once the alarm has been silenced?

 

[Spark123]

Not quite as neat as Mattylads:

Picture Title

• Spark123
• 8 Jan 2012
• 1

R1, R3, R5 need to be single pole, R2, R4, R6 double pole.
There are 3 acknowledge momentary pushbuttons, one for each trip. Nothing to stop you using one 3 pole momentary pushbutton if you want.
When a trip operates the lamp and buzzer sounds, pressing ack silences the alarm. The lamp will remain on and buzzer silenced until the trip is reset. On the right of the drawing, R1, R3, R5 are NO and R2, R4, R6 are NC

As a side note, for important alarms normally closed systems are often used as they are fail safe but as per your design brief, a normally open system is drawn.

Do I get a gold star??

edited to add links to relay logic, no gold star now

 

[wreck-it-steve]

Does the LED need to still light once the alarm has been silenced?

Yes until the aux contacts are back to normal

 

[mattylad]

How about this then?

The input aux relays latch the RL1-RL3 to keep the leds on, latching required because of the float. The buzzer is powered via a 2 coil set/reset relay that is not silenced until the N/O push button is pushed.
Any other input going active will turn the buzzer back on.

All reset via the main KS/PB & fuse added for the heck of it.

3 WAY ALARM WITH ACCEPT2

• mattylad
• 8 Jan 2012
• 1

If this was done with a PIC it would entail 3 inputs from the aux relays, a pic, reset and silence switches (a single biased keyswitch can do this) leds/resistors and the buzzer.
You would need to write some code though lol.

 

[Spark123]

I'm struggling to read the drawing as the letters are a bit small and my laptop only has a titchy screen
Does accepting the buzzer inhibit the other two alarms from sounding the buzzer?

 

[mattylad]

No.

Its a set/reset relay that changes state depending upon which coil has 24v on.

Here is a link to a PDF.

Click on FILE the "download original"

 

[Spark123]

I'm looking at your drawing and thinking the bottom relay will be energised all the time once a trip operates. When a second trip operates it will remain in the same state.

 

[mattylad]

Bugger yes! (its been a few years since I last did this lol)

BRB.

 

[Spark123]

I'll let you copy mine if you like ^^^^^^^