Need help with school bell

[no_your_n_e_me]

I work at a primary school in australia and I want to be able to control the bell from the administration computer. So far i have been able to find a really good computer controlled power plug here **broken link removed** which i can use to schedule the bell times and days but the problem is it is only programmable down to a minute which means it will turn the bell on then i can only shedule it to switch off after a minute. Does anybody know of something i can plug into it which will switch on for a specified time each time power is introduced to it and reset when it is turned off?

 

[Marks256]

I didn't know that bells turned on-and-off with the flip of a switch...

You could always home-brew something...


Could you give more information? For example; What is the current setup, how much say do you have in what happens (would YOU be allowed to rig something up...), and also, how many bells are we talking here?

 

[mroberts]

You should be able to get a basic timer kit from Jaycar or Dick Smith. Set that timer to be triggered by your controller, and configure the timer to run for your desired bell time automatically on power-up.

 

[no_your_n_e_me]

Ok hmmm i think ive done it.....

Ive found this device **broken link removed** (under timers and its the m1smt) which seems to be the 1 for the job... the guy on the phone said it would work for what i want so im just getting a secound opinion does anyone have any reason to believe this may not work as i want it to? Im thinking if i put power into the usb controller **broken link removed** then out of that device and into the timer then from the timer to the bell it should only go into the bell for as many seconds as i set the timer to even if the usb device feeds power into it for a min or so. And to answer your question Marks256 yeah they would allow me to rig something up coz i have 100% say im the IT tech at the school and the pretty much throw anything technical @ me haha and they trust i will do it right. But this kinda isnt my field but i think im gettin it. The great thing is a regular bell timer with a crappy lil digital interface that goes off everyday of the week would end up costing around AU$2000-3000 while this system ive come up with will be fully customisable and you will be able to set several bell times during which ever days of the week you want and all through the admin computer. And its looking at only costing around AU$350! Currently there is only 1 bell as it is really quite a small school and it is operated simply by pushing a button on the wall and holding it in for the desired amount of time... they get the seniour kids to do this as a duty but theyre not exactly reliable! haha anyway tell me what you think eh?

 

[Hero999]

Why don't you use a PLC?

I remember at middle school every student took in turns to be on bell duty. They had the day of lessons and had to ring the bell between lessons, other duties included welcoming visitors and making tea.

 

[Sceadwian]

PLC's are a throwback to old engineering ways. Modern micro controllers and driver modules can do far better, even on a printer port.

 

[Hero999]

That's exactly what modern PLCs are, except they have the advantage of being encased in a ruggedised box, can operate from a wider temperature range and withstand more vibration. Some come with programmers and most can also be programmed from a usb cable, parallel or serial port.