Electric shower timer

Hi everybody,

If you have children know very well i'm talking about!
Need a count down timer that can have adjustable total timer (in a range from 20min. to 5min.), a current switch to monitor when the shower is on or not and then starts or stops the countdown until reach zero and let1s say two digits to monitor the remaining time. Let's simulate an event:

1) Your 10 year old child begins to take a shower (and of course he checks the time remaining until the shower is automaticaly turned off);

2) Then he closes the water and the shower stops at this time the current sense laps (doesn't zero) the stop watch and when he opens again the water and the shower turns on the countdown begins to count again;

3) If the timer reaches zero it activates a relay and only deactivates the relay after let's say 10 minutes.

Is there any idea?

Very thank you Fernando!

Hi fjpompeo

nice idea .... now imagine this .... child getting ready for school, takes shower and runs out of time - but is still covered in shampoo from washing their hair - what will hassled parent do?
1) tell the child to go to school wet & soapy
2) wipe most of the soap off with a towel and rinse in the sink
3) turn on shower - thereby negating the reason for timer - child wins more time!

my money is on no.3

OR
child no.1 stops clock to make child no.2 wait - arguing 'My time has not run out yet!'
child no2. angry kicks door off shower .....

Good fortune with your idea ... Polymath

My sugestion his to use an fluid counter combined with a time control
No very dificult to build
Just need to arrange the sensor.

this the same as a project i sugested to a friend of mine son , he said he could do the programing into a pic, i sugested : water flow sensor, temp sensor,buzzer, two digit display and led indicators. the theme was water and energy savings.
it would have three optional times 5, 10 and 15 minutes lapses, an emergency stop, the buzzer will anounce three times like 3, 2 and 1 minute left, the buzz being intermitent and faster at the end of the cicle and a final long one, a 5 minute wait period before restart, the counter will stop when water ceases to flow, and restart when you open the valve again, the temp sensor is next to the heating element to disable the sistem in case of overheating. the control is near the shower with a membrane keypad etc etc.

u can use atmel8951 micro controller to do ur idea its grat idea

In military submarines water is scarce. They have a person assigned to watch the sailors showering and throw them out of the shower stall when the time is up. This motivates the sailor to be quick. Perhaps the shower should be locked and the parent has the only key and stands there watching.