Shower Timer question......

[ronryben]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

 

[Mike Silva]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

I think you need to think this through some more. Do you really want
to leave people in the shower, dripping soap, with the water off? At
the very least, don't turn the water off entirely, but just drop to a
low pressure. After a long and unmistakable warning.

What are you trying to accomplish, and who is your target user?

 

[D from BC]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

First thought... 2 monostables + logic

One MMV controls the shower ON time.
The other MMV controls the shower OFF time.


D from BC
British Columbia
Canada.

 

[DJ Delorie]

What you want is something that shuts off the hot water heater when
the shower is running. Shower off, water heats up. Shower on,
limited amount of hot water - then you get a cold shower.

Flow sensors are cheap, and you can wire it in with the heater's
temperature sensor wire.

 

[ronryben]

My target user? well........I want to limit the shower times of a few
teenagers I have here. All the talking and what not has had no
results. I agree that I should either turn off only the hot water and/
or first limit the flow as a warning. Turning off the water heater as
mentioned in a reply won't produce the results I'm looking for. The
water heater is a 45 gallon tank style.

My recent in depth electronics experience is lacking......I do however
some leftover knowledge of my training in the US Army years ago and my
1 year stay at a tech school. I still work in repair of basic 12vdc
and 12vac circuits. Furnaces and such.

So you may have to hold my hand a little on this one.

 

[Paul Hovnanian P.E.]

What you want is something that shuts off the hot water heater when
the shower is running. Shower off, water heats up. Shower on,
limited amount of hot water - then you get a cold shower.

That depends on the size of the heater. In the EU, I know that they use
small tank heaters, or even demand heaters. But some of us in the US
have 80 gallon tanks. Shut that off and you've still got an hour's worth
of shower.

I like the previous poster's idea to shut off the hot (give them a 3
minute warning beeper). Better yet, measure the time of flow and count
down only when the shower is running. My shower has a shut off to cut
the flow until you need it to wash/rinse.

 

[DJ Delorie]

You could try putting the *lights* on a timer.

For the hot water heater, you could add a solenoid-type bypass valve.
The hot feed becomes immediately cold.

 

[Spehro Pefhany]

My target user? well........I want to limit the shower times of a few
teenagers I have here. All the talking and what not has had no
results. I agree that I should either turn off only the hot water and/
or first limit the flow as a warning. Turning off the water heater as
mentioned in a reply won't produce the results I'm looking for. The
water heater is a 45 gallon tank style.

My recent in depth electronics experience is lacking......I do however
some leftover knowledge of my training in the US Army years ago and my
1 year stay at a tech school. I still work in repair of basic 12vdc
and 12vac circuits. Furnaces and such.

So you may have to hold my hand a little on this one.

Solenoid valve and control it with some circuitry. The user starts the
timer with a well-insulated momentary pushbutton switch from outside
the wet area (for safety). The shower runs for x minutes, then pulses
the hot water to off for a few seconds as a warning, then allows the
shower to run for another period of time (a minute?) to allow the user
to rinse and exit. The circuit enforces a delay after the end to
prevent re-triggering for 10 more minutes.

You may want to consider what happens if the user leaves the hot water
tap on, but the water is turned off by the solenoid. You may not wish
to depend on the solenoid to control the water entirely (and it might
not be to code, and your insurance might not pay off if there was
water damage when nobody was around-- which could run into tens of
thousands of dollars or more).

Easiest way would be a small PLC or a bunch of timer relays, but that
would be fairly costly. A small microcontroller or some timers. Maybe
someone here feels like drawing up a circuit based on 4000-series CMOS
for you, but consider the other issues.

Best regards,
Spehro Pefhany

 

[ronryben]

You may want to consider what happens if the user leaves the hot water
tap on, but the water is turned off by the solenoid. You may not wish
to depend on the solenoid to control the water entirely (and it might
not be to code, and your insurance might not pay off if there was
water damage when nobody was around-- which could run into tens of
thousands of dollars or more).

That shouldn't be an issue. The shower fixture is a single knob moen.
So the one knob controls both hot and cold. The kids are so trained,
after years of use, that I am sure they would reach down and push the
knob in to turn off the "now cold" water once the solenoid closes to
turn off the hot water supply. If they don't? Well then the cold will
just continue to run. My original thought was to actually control ONLY
the hot water supply, warning or no warning.However, I do prefer the
warning without making things too complex.

Easiest way would be a small PLC or a bunch of timer relays, but that
would be fairly costly. A small microcontroller or some timers. Maybe
someone here feels like drawing up a circuit based on 4000-series CMOS
for you, but consider the other issues.

That would be GREAT! Thanks for all the input so far!

 

[[email protected]]

My target user? well........I want to limit the shower times of a few
teenagers I have here. All the talking and what not has had no
results. I agree that I should either turn off only the hot water and/
or first limit the flow as a warning. Turning off the water heater as
mentioned in a reply won't produce the results I'm looking for. The
water heater is a 45 gallon tank style.

My recent in depth electronics experience is lacking......I do however
some leftover knowledge of my training in the US Army years ago and my
1 year stay at a tech school. I still work in repair of basic 12vdc
and 12vac circuits. Furnaces and such.

So you may have to hold my hand a little on this one.

I have seen such contraptions at campgrounds and such. Surely they
must be a commercial product. You know the deal, 1$ per 5 minutes or
so.
If you want to take long hot showers for "free", sign up to a gym. I
take mega long showers there and so I only use my home shower 2-3
times a week.

 

[mpm]

I wonder if you can do this mechanically, and not involve electronics?
Also, it might be better to have two "switches". The first slows the
water, the second cuts it off. Leave enough time in between to at
least rince off.

-mpm

 

[linnix]

My target user? well........I want to limit the shower times of a few
teenagers I have here. All the talking and what not has had no
results.

Same here. They either don't shower for days or shower for 30 to 45
minutes.

I agree that I should either turn off only the hot water and/
or first limit the flow as a warning. Turning off the water heater as
mentioned in a reply won't produce the results I'm looking for. The
water heater is a 45 gallon tank style.

You need a electrically controlled valve to turn off the hot water
line. Sprinkler valve might work, but not sure if it will be a problem
with hot water.

My recent in depth electronics experience is lacking......I do however
some leftover knowledge of my training in the US Army years ago and my
1 year stay at a tech school. I still work in repair of basic 12vdc
and 12vac circuits. Furnaces and such.

12V might not be enough, perhaps 24V to 48V valve.

 

[gearhead]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

Dedicate a real small water heater to the shower. Like something
meant to install under a sink. So after Mr. or Ms. Teenage Waterbug
uses about ten gallons, it gets cold, and no more hot water for a
while!

 

[PeterD]

I think you need to think this through some more. Do you really want
to leave people in the shower, dripping soap, with the water off? At
the very least, don't turn the water off entirely, but just drop to a
low pressure. After a long and unmistakable warning.

What are you trying to accomplish, and who is your target user?

Naw, just turn off the hot water... Leave the cold running!

IMHO, in agreement, this is not a very bright idea--close to living
dangerously actually. At least lock up all the sharp knifes when you
set this thing up!

 

[ronryben]

I have seen a unit available. Retail is over $200. Just figured I
could find a quick simple explanation and possible diagram on how to
assemble such a device, including the circuitry involved.

Not a bright idea? AND hiding the knives? LOL.......from whom? The
teenagers? LOL..... I am willing to deal with whatever fallout
develops WHEN I start limiting the showers. Knives or no knives!

Thanks for all the help. I am still intent on building a device that
will do what I want.

Described much better by Spehro Pefhany in response to my original
post:

Solenoid valve and control it with some circuitry. The user starts the
timer with a well-insulated momentary pushbutton switch from outside
the wet area (for safety). The shower runs for x minutes, then pulses
the hot water to off for a few seconds as a warning, then allows the
shower to run for another period of time (a minute?) to allow the user
to rinse and exit. The circuit enforces a delay after the end to
prevent re-triggering for 10 more minutes.

 

[Ralph Barone]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

Start by looking in gardening supplies. Here's one example (wrong
country, but you get the idea)
http://www.garden4less.co.uk/proddetail.asp?prod=94067

 

[mpm]

You need a electrically controlled valve to turn off the hot water
line. Sprinkler valve might work, but not sure if it will be a problem
with hot water.

-
What about those valves that are used in automatic clothes washers?
They're pretty simple and inexpensive.

I think they work on 120VAC, so not sure if that's practical for you
application, but maybe?

 

[[email protected]]

Have done some searching and can't seem to find what I need. I am
looking for some help with setting up a device to limit shower times.
An electronic timer that would limit a shower to preset length.
Basically a circuit that includes a relay to control a solenoid valve
on a water line. It would not be necessary for the user to program the
length of the cycle. The timer would need to me designed in such a way
as to not allow the user to reset the shower cycle. With at least a 10
minute delay between one shower ending and another starting.
Any ideas or "kicks in the right direction" is appreciated. I don't
want to spend 200 bux on the ONLY device I have been able to find.
Thank you.

Even if you can design this, the logistics will be a mess. Where do
you mount the controls? Where do you splice in the valves. This is a
hell of a lot of work.

 

[Mark]

Even if you can design this, the logistics will be a mess. Where do
you mount the controls? Where do you splice in the valves. This is a
hell of a lot of work.

turn the temp setting in the hot water heater down so that you have to
set the valve to almost full hot to get to shower temperature ...
that will consume the water faster and use a little less energy, the
water will gradually get colder as it is consummed... and low flow
shower head...

If you spend $200 for controls and valves etc, did you figure how long
is your payback time?

Mark

 

[JosephKK]

Same here. They either don't shower for days or shower for 30 to 45
minutes.


You need a electrically controlled valve to turn off the hot water
line. Sprinkler valve might work, but not sure if it will be a problem
with hot water.

I recommend a valve for a washing machine or a dishwasher.
Inexpensive, available and known to be able handle the job, probably
120 Vac though, so an SSR is needed to control it.