Alarm Display Project - Electronic Circuits Projects Diagrams Free

loranimal · 19th March 2005, 12:26 AM

Hello,
I need some advice on what I hope will be a simple project. I have an alarm panel containing twelve 24vdc relays. Each relay is specific to a different alarm loop. For instance, one alarm is "intrusion" and another is "fire". When 24vdc from an alarm loop is present across a relay coil,the relay actuates. I would like to tie an output from a contact on each relay to some type of display device that indicates which alarm is activated, numeric or alphanumeric if possible. Does such a device exist?

Take it easy on me guys - I'm just a technician!

Pommie · 19th March 2005, 06:01 AM

Why not just put a LED and resistor in series with each other and wired across each relay coil.

The resistor would need to be around 22÷0.02 = 1100 = 1.1 K ohms

HTH

Mike.

loranimal · 19th March 2005, 01:12 PM

Thanks Mike,
I was actually considering that. All of the relays are inside a steel enclosure with a hinged cover. I could drill 12 holes, insert 12 led's, and have a label beside each. I guess I was thinking of something a little more fancy - but your idea makes sense too.

JFDuval · 19th March 2005, 04:25 PM

Why not using an lcd if you want it fancy?

samcheetah · 19th March 2005, 05:14 PM

i would recommend a microcontroller based design. you can interface the signals from your sensors/transducers to a microcontroller and connect an LCD with it. the microcontroller will display all the information of the sensors and it will also control the alarm outputs (bell, strobe, dialer etc)

by incorporating a microcontroller you would acheive a great level of flexibility. you can add alot of features to your design by just writing a few lines of code. and you can make a design that would be upgradable in the future by just changing the firmware.

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19th March 2005, 12:26 AM	(permalink)
loranimal	Alarm Display Project Hello, I need some advice on what I hope will be a simple project. I have an alarm panel containing twelve 24vdc relays. Each relay is specific to a different alarm loop. For instance, one alarm is "intrusion" and another is "fire". When 24vdc from an alarm loop is present across a relay coil,the relay actuates. I would like to tie an output from a contact on each relay to some type of display device that indicates which alarm is activated, numeric or alphanumeric if possible. Does such a device exist? Take it easy on me guys - I'm just a technician!

19th March 2005, 06:01 AM	(permalink)
Pommie	Why not just put a LED and resistor in series with each other and wired across each relay coil. The resistor would need to be around 22÷0.02 = 1100 = 1.1 K ohms HTH Mike.

19th March 2005, 01:12 PM	(permalink)
loranimal	Thanks Mike, I was actually considering that. All of the relays are inside a steel enclosure with a hinged cover. I could drill 12 holes, insert 12 led's, and have a label beside each. I guess I was thinking of something a little more fancy - but your idea makes sense too.

19th March 2005, 04:25 PM	(permalink)
JFDuval	Why not using an lcd if you want it fancy? __________________ JFDuval jfduval --@-- aqra.ca http://www.aqra.ca

19th March 2005, 05:14 PM	(permalink)
samcheetah	i would recommend a microcontroller based design. you can interface the signals from your sensors/transducers to a microcontroller and connect an LCD with it. the microcontroller will display all the information of the sensors and it will also control the alarm outputs (bell, strobe, dialer etc) by incorporating a microcontroller you would acheive a great level of flexibility. you can add alot of features to your design by just writing a few lines of code. and you can make a design that would be upgradable in the future by just changing the firmware.