Bell Systems
From nswccWiki
Contents |
Introduction
There are a few options for schools looking at automating their Bell Systems.
The options depend on what your existing system uses. Do you only have electric bells or do you have speakers in classrooms?
I have also included below some posts to NSWCC in response to a query on this topic.
Speakers
Computer based systems are available that will play different MP3s at set times for set length as a bell system.
e.g
Oakley Snr College has music play as a bell, as experienced by CCs on Sydney Region CC days.
TimeChimes
TimeChimes recommended by Greig Tardiani.
Quote: A number of schools use it. Cheap and dead simple to use and change if necessary.
We have it set up on an old PC and what ever sound you want plays through the speaker socket in the PC to your bells amplifier.
Put a different sound on each period if you want.
Bells
If you want to automate a manual bell system there a 2 main options. A standalone device or one directly attached to PC.
You can also get devices that connect to the parallel port and trigger a relay for the bell. These require the computer to be on for Bell to work.
Manual devices can be programmed at device, but they may be hard to program complex behaviours, such as different days, A/B weeks and school holidays.
BellMinder
Sydney Boys recently installed a system that combined these two systems to control our bells.
The BellMinder system is a standalone device that is connected to a computer for programming using a serial connection over cat5.
We wired the connected the device to a spare network port in main office, and routed it directly to a spare port in DPs office.
This allows schedules to be programmed from DP in his office and sent to the Main office.
Features
Device:
- Single button to ring bell
- Can easily start evacuation or lockdown bells.
- Shows time of the next scheduled bell
Software:
You create bell sets that tell the system what time to ring the bell and for how long. Then you assign these bell sets to a calendar of days.
- Can very quickly setup a yearly timetable with holidays
- Can set 14 months to include Christmas holiday break
Disclaimer: Sydney Boys was offered to be a demonstration school and received the BellMinder device for free. We paid for shipping and installation. So far we have been very happy with BellMinder.
Build your Own
From John Blackmore, Turramurra High School
To start I wrote a turbo pacal program to print to the the RS232 interface.
I fed the signal through a bridge rectifier and 2 transistors (need a 9Volt power supply) and sent it to a relay switch which the electritian wired into the box that rings the bells manually.
Parts only cost about $15 from dick smiths.
Now we use a database to "print to the RS232 interface" allows us to factor in holidays etc.
If you had audio output, you should just be able to rectify this and send it straight to the relay switch.
Zelio Logic Smart Relay
From Stephen Goldsworthy, Merewether High School:
Our automatic bell system (that came off the Ark) failed and a new controller was required.
After about 2 weeks of searching, I found a programmable switching device that would connect to our bells circuit.
They are running on a separate system around the school.
The unit is a Zelio Logic Smart Relay Model no.SR2B121FU. The programming language is Zelio Soft. (Very easy to use)
The company that handles these in Australia is Schneider Electrics http://www.schneider-electric.com.au/It comes with reasonable instructions. Our electrician eventually worked it out.
The unit has four relays, I'm using these as follows 1 for the bells the other 3 run indicator lights so that you know which program is running.
There are 8 inputs, I'm using 4 and these are used to run other programs. i.e. lockout bells, lockdown bells, evacuation and a manual override.
The bells can be timed by the minute, which is the lowest unit the program will work with.
I have programmed the unit to only operate the bells during school time, (no problems with the neighbours).
You can run different bell times on different days, (our Mon, Tue, Wed are all the same, Thursdays are different and Fridays are different again) and different patterns of bells for different situations.
