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Discussion Starter · #1 ·
Several months back we had a small discussion of using a timer to turn things on after a specific period rather than turn them off as most timers are designed. We used the term countdown for the ones we found but found none to "countup" to turn the power on after a specific time.
Maybe there was an obvious solution that we overlooked? I have a cheap timer which has now failed and that leaves it open to experiments.


This is the standard cheap mechanical timer that we see so often.


This is what we find inside. A simple mechanical link to operate a microswitch. The micro is what I circled in red. A pretty standard microswitch that sells for a under a couple dollars, it is a SPST to open or close one side of the power.



The switch just rests in the box on a couple plastic pins so that it can be pulled out very easy. So if we want to change from turning power ON to let the timer turn it OFF at a specific time to letting us set how long the power is OFF and then the timer turn power ON, we just need to change out this microswitch.
If your timer has a NC, changing it to a normally open will reverse the way it handles power.
Or with a bit more fuss on fitting the extra contacts into the space, one might add a switch of this type and have the option of wiring it either way.
Parts Express SPDT Snap-Action Standard Micro Switch with Lever


If I remember the question, there was a desire to turn filters off during feeding and let the timer turn them back on after that to avoid us forgetting?
Maybe the best solutions are the simple ones?
 

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I am so confused.
Why not just buy a modern timer that has the non removable pins? It will do exactly as you're trying to do. Pins are all pulled up then push all the pins down between the start and stop time. Each pin is 15 minutes to you can push them all down except one at the desired time.
 

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Discussion Starter · #3 ·
What was wanted was not a standard timer to set and forget but a way to go in , turn the timer on to a set amount and then it return the power once that time is up. We found none to do that. I think the use was for when feeding fish and wanting to turn the filters off for bit but then have power restored.
Simple timer but with an opposite function to turn power off rather than on .
 

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a digital timer will allow you to set on off times down to the minute, and the one i have allows you to have 10 different programed on off times, these can also be set by day of week, m-f, s-s, etc...

Though I'm expecting you're looking for something more like the bathroom timers you see in hotels alot, twist the knob, something turns on and then turns off x minutes later. though in reverse, you're looking for something that turns off for x amount of time.

You could probably use one of those wired to a relay that is normally closed such that the when the timer is "on", it opens the relay, turning what ever is on, off
 

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Discussion Starter · #6 ·
I may have forgotten the details of what the OP was wanting but his need was not that simple and we never found an answer for what he might use. Maybe he will spot this post and fill us in on why the common items are not what he needed. I think that he had considered the relay idea but was hoping for something simple. This post is only as thought that it might work for what he needed but I'm pretty short on details as it is not my project but somebody else. Anybody remember who wanted the help?
 

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GraphicGr8s wanted the info. GraphicGr8s goes to the fish house on an irregular schedule. GraphicGr8s can go to the fish hose at 6pm or at 10pm. Or anytime in between and on weekends earlier. Sometimes GraphicGr8s doesn't go out to the fish house. Like tonight. Since that is the case standard timers don't work for GraphicGr8s. GraphicGr8s needs something that GraphicGr8s can set when GraphicGr8s walks in, waits a few minutes for the overflow to stop then feed. GraphicGr8s then gives the fish time enough to eat then GraphicGr8s turns the pump back on. When GraphicGr8s remembers. If GraphicGr8s forgets then the next day GraphicGr8s has to drain the overflow and sump. GraphicGr8s does not like that.
GraphicGr8s realizes now why GraphicGr8s does not do third person.
 

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How to Make a Long Duration Timer Circuit - Homemade Circuit Projects



Power the above circuit with a 12V power supply.

The power to the pump runs through the relay on the right.
The switch (not shown in diagram) is a latching type Normally open, and is either before or after the 12V supply.

To power on the pump, plug in everything and move switch to on position... the pre set delay will take place and then the pump will turn on.
To feed fish, toggle the switch to off and back to on, the pump will turn off for the pre set delay time and then come on again.
 

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You can probably work something out with a contact switch on the door to the fish house. Door open, pump is off for closed, pump is on. Want to feed prop the door open...

As a side note why do you need to drain the overflow and sump if you forget to turn the pump on?


A quick Google search turned up Door Jamb Switch Kit
 

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Discussion Starter · #11 · (Edited)
Thinking back, I realize the basic question was not going to be solved with this idea. We got down to asking why there are so many simple timers to turn power off but so few or none to turn it on again? Simple was what was needed and I don't think we ever got around to a simple timer off the shelf.
Anybody want to start a GO Fund Me to turn out a few of these? I can think of two guys who might buy them! On the other hand if somebody has a junk spring drive timer, I could tear it down to see how it might be rewired.
But then I don't tear down the working stuff so the project may be on hold for later.
 

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Pixel Prestidigitator
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You can probably work something out with a contact switch on the door to the fish house. Door open, pump is off for closed, pump is on. Want to feed prop the door open...

As a side note why do you need to drain the overflow and sump if you forget to turn the pump on?


A quick Google search turned up Door Jamb Switch Kit
Great idea if I want to start a skeeter breeding farm.
Every time I enter or leave the pump would cycle.

Right now I don't have the sump hooked up. Water just flows to a 5 gallon bucket and back up again. This one tank is heavily planted and lightly stocked so a Whisper 60 and water changes handle actual filtration. The pump is water circulation. I don't like putting stagnant water back into the tank. Upside is the bucket and over flow is about 10 gallons. So a nice 10% extra water change.

Bump:
Thinking back, I realize the basic question was not going to be solved with this idea. We got down to asking why there are so many simple timers to turn power off but so few or none to turn it on again? Simple was what was needed and I don't think we ever got around to a simple timer off the shelf.
Anybody want to start a GO Fund Me to turn out a few of these? I can think of two guys who might buy them! On the other hand if somebody has a junk spring drive timer, I could tear it down to see how it might be rewired.
But then I don't tear down the working stuff so the project may be on hold for later.
I haven't had the time to putz with it at all. I'll wind up getting a countdown timer, and a relay with 120 coil and use the CDT to energize the coil when feeding. One advantage is if something happens to the CDT or the relay coil, or if I have to use a 24v coil and transformer if anything goes bad pump runs.
 

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Discussion Starter · #13 ·

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Did you look at the NC (normally closed) relays? You could wire one into a circuit using one of the normal light countdown timers. When the timer is "OFF" the circuit is closed and the pump is running. You give the timer a twist to activate it and the relay opens for however long you set it to. When the time runs out, the relay shuts and turns the pumps back on.
 

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You could use one of the digital timers, set every ~2 hours or so to turn on (they will function without an off time) all it takes is a couple pushes on one button to override it and turn it off. you can then do your thing, push the button again and turn it back on, or if you forget it'll hit the next programmed on time and turn itself back on again. I actually do this in reverse to turn my lights on early on the weekends (when ever i wake up lol) and it defaults back to it's regular timing cycle
 

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Pixel Prestidigitator
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Did you look at the NC (normally closed) relays? You could wire one into a circuit using one of the normal light countdown timers. When the timer is "OFF" the circuit is closed and the pump is running. You give the timer a twist to activate it and the relay opens for however long you set it to. When the time runs out, the relay shuts and turns the pumps back on.
That's exactly what I meant. That has the advantage if something happens to the timer or the coil the pump still runs.
 

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Well, now that I looked at the entire thread, it seems I was beat to the punch...

Though I'm expecting you're looking for something more like the bathroom timers you see in hotels alot, twist the knob, something turns on and then turns off x minutes later. though in reverse, you're looking for something that turns off for x amount of time.

You could probably use one of those wired to a relay that is normally closed such that the when the timer is "on", it opens the relay, turning what ever is on, off
I still think this will be the easiest way to do this, although not the cheapest. You don't need any special skills just a minimal handyman type knowledge. From the posts I've seen GraphicsGr8s make, I think that's covered. Two off the shelf parts, a bit of wire and elbow grease and you're done.
 
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