Need some help with a design

[Diesel]

Hi guys

First of all a little about me, I last did micro electronic design work when I did a GCSE in '88, since then the most I've really needed to do is replace popped capacitors or soldered on batteries / replace invertor boards.

Nothing to do with design at all, Its all been electronic gaming machine repairs so I've forgoten most of what I've learnt.

I want to get back into creating my own projects, but I have one I want to put to put together as a priority for my work place and I'm not sure I can relearn enough that quickly, so would be grateful for any assistance in designing a circuit.

The problem.

My work place has machines that customers can sit at for hours, but want to reserve while they nip to the loo, or go have a cigarette break. to combat this we have signs that say "reserved for 10 mins" the problem is there is no real way of policing this and it gets abused a bit.

This causes problems where customers complain to the point employers want to remove the reservation signs then customers who legitimately use them complain as they cant nip to the loo without risking someone jumping on.

Solution

I'd like to create a circuit that we can fit into these signs (they are A4 sized, and we can get them made to contain a circuit) that would provide a visual indicator of how long is left (thinking 10 led's with each min passed knocking one out but open to whatever is easiest)

Off and reset buttons to be done by key (maybe a jack plug or deans wired to create a on) so they cant be tampered with.

I'm thinking this would involve 555 chips and calculations of resistors which TBH I am as near as dammit back at square one knowledge wise.

Any help on this would be really appreciated.

Thanks

[Pauldf]

Egg timer?
People shouldn't sit at a PC screen without a break once an hour, I believe there is a HSE regulation on this.

[Diesel]

Egg timer?
People shouldn't sit at a PC screen without a break once an hour, I believe there is a HSE regulation on this.

If this was employees at a workstation you are right they are protected by the health and safety (display screen equipment) regulations 1992.

These however are customers playing slot machines for leisure so not covered.

handing our customers an egg timer isn't quite going to work

[David]

What about a kitchen timer which will count down from 10 mins (or whatever you set)? There are 100s on Amazon so you should find plenty suitable to be installed in a sign. They are very cheap, so why reinvent the wheel?

[Diesel]

Unfortunately using these would mean customers would be able to start /stop or reset them.

I want to make something that looks good and can't be easily tampered with otherwise we'll be back to having the signs abused again.

[Pauldf]

I can't see it being difficult to start with a 10m kitchen timer and adapting it to your own needs, ie putting reset etc on a key switch or disabling the buttons that are not needed.

[Diesel]

yeah I think this is going to be the easiest.

its not perfect as when people are throwing money at a machine to win up to 20k, I'd like to use kit that looks designed for the job rather than repurposed.

I'll look at this for now as a stop gap, and as I do want to reteach myself I can always revisit the project later.

[Diesel]

I've found this, it looks like it would be ideal.

would just need to tweak it, not sure about the 10 mins being because of leaky capacitors.

any ideas on fixing that to a constant 10?

http://electronicsclub.info/p_timer.htm

Quick youtube vid here

https://www.youtube.com/watch?v=hVJ6KQ34rss

cheers