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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Joe Camper on December 06, 2010, 06:46:19 AM

Title: Timed delay relays
Post by: Joe Camper on December 06, 2010, 06:46:19 AM
We have a Raritan maserator toilet and it currently has a 2 button function. 1 momentary switch dumps/flushes and the other opens the water solonoid to refill the bowl.

I would like to make it more like home and with a simple push of 1 momentary switch get the masserator to go for 2 seconds or so and then the water solonoid to remain on for an additional 10 or 12 secs whatever it takes to get the water level in the bowl back where I want it.

I believe I only need 1 timed relay the one for the water solonoid. If I can get the masserator to run while the switch is engaged (without any timer) and after I let go of the switch the solonoid for the water will remain on for an adjustable timed sequence that would work great.

I found this info but need help proceding. What relay am I needing?

http://factorymation.info/relays/TDRPRO-5002.pdf (http://factorymation.info/relays/TDRPRO-5002.pdf)

I found this is it what I need?

http://www.factorymation.com/s.nl/it.A/id.5592/.f?sc=2&category=100 (http://www.factorymation.com/s.nl/it.A/id.5592/.f?sc=2&category=100)


I also have been sent this info to build one myself will it work?.   http://www.aaroncake.net/circuits/relaytim.asp (http://www.aaroncake.net/circuits/relaytim.asp)
Title: Re: Timed delay relays
Post by: Sean on December 06, 2010, 08:02:41 AM
Joe,

Lots of ways to skin this cat, but it is not trivial.  Depending on what timer you end up with and how many settings it has, you might need to either change the momentary switch to double-throw and/or add one or more additional relays to implement the entire sequence.

I have some experience with these types of circuits and I can tell you that it usually takes me a couple hours to find the right timer and draw up the circuit; there are literally hundreds of timers on the market and you can spend as little as $20 or as much as $200 on an application like this.  As the MagneCraft document you linked says, "Understanding the differences between all the functions available in time delay relays can sometimes be a daunting task."  Your preference for a single timer complicates things a little bit, and there is the additional consideration of whether or not the circuit is allowed to use power full time or if you want it completely unpowered while not in use.

I would advise against the build-your-own circuit you linked.  For one, it is strictly an Interval timer and you probably need something more complicated such as Delay-On-Break.  For another it uses power full-time.  Lastly, if you are having trouble designing your own circuit using off-the-shelf parts, troubleshooting a DIY timer has a steep learning curve and the aggravation is probably not worth the couple of bucks you will save.

The one hint that I can offer without having to spend an hour or so on it myself is that the optimal solution, if you want the circuit to be powered down when not in use, will probably involve a double-pole timer wherein one of the poles is used to feed power back to the timer itself until the cycle completes.

If you really get stuck, drop me a note.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: Timed delay relays
Post by: Rick 74 MC-8 on December 06, 2010, 03:35:22 PM
Sean

    I don't want to steal this thread or start anything but couldn't he just use any timer and use the load side of the relay to supply the power to the timer so his momintary switch would the sequence?
Just asking?

                                                                          Rick 74 MC-8
Title: Re: Timed delay relays
Post by: James77MCI8 on December 06, 2010, 07:06:00 PM
 http://www.factorymation.com/s.nl/sc.2/category.11443/.f (http://www.factorymation.com/s.nl/sc.2/category.11443/.f)
This will work. it comes in a 24 VDC and 110VAC model and is fairly simple to program and pretty inexpensive too.
Title: Re: Timed delay relays
Post by: Sean on December 06, 2010, 08:04:02 PM
Quote from: Rick 74 MC-8 on December 06, 2010, 03:35:22 PM
... couldn't he just use any timer and use the load side of the relay to supply the power to the timer so his momintary switch would the sequence?

If all that was needed here was to time an interval after a momentary button press, then almost any timer would work and the circuit would be very simple.  However, that's not how I understood the problem.  What I understood was as follows:

1.  Press button to start macerator.
2.  Hold button down for as long as needed/desired to complete macerating.
3.  Release button to start fill cycle.
4.  Fill cycle continues for pre-set time as set by timer.
[5. All power to the relays and timer(s) cuts off.]

I added that last one myself, as that's how I would want it to work.  But even just 1-4 is not as simple as "Push button to start timer."

This is why I wrote that the two-part complete cycle might require some additional circuitry, either a double-throw momentary switch, a relay, or both.

At some level, the circuit is actually simpler if you use a single button and two timers, where the button starts the first timer, which times the macerating cycle, and when that timer expires it kicks off the second timer, which times the fill cycle.  But the OP said he wanted to do it with just one timer; not sure if that's to save money (it will) or because the macerating cycle requires a variable amount of time depending on, umm, the amount of material in the bowl, and he wants to be able to hold the button as long as necessary.

BTW, posting a part number with "this will work," while not incorrect, is also not the whole story;  as I wrote above, there are hundreds if not thousands of part numbers that "will work" for this application.  It's getting the rest of the circuit correct that's the tricky part.  FWIW.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: Timed delay relays
Post by: Joe Camper on December 07, 2010, 05:17:22 AM
Thanks everyone I am going to modify it as described. I will be taking this thread and bouncing it off my electrical yoda and friend who is helping me on this and I will also post up my progress and results and solution.

As far as 1 relay or 2 IMO performance, cost and then simplicity would be what I am shooting for in that order.

Thank you all again.
Title: Re: Timed delay relays
Post by: smokedetector on December 07, 2010, 06:29:37 AM
If you are looking for a simple solution,The product that James posted "will work" is the answer. It will do everything you are asking and more.
Title: Re: Timed delay relays
Post by: James77MCI8 on December 07, 2010, 04:21:58 PM
http://www.factorymation.com/s.nl/it.A/id.42/.f?sc=2&category=1296 (http://www.factorymation.com/s.nl/it.A/id.42/.f?sc=2&category=1296)

Here is the part number SG2-29HR-12. 12 VDC. If interested I will write the program for you.
Title: Re: Timed delay relays
Post by: Joe Camper on December 07, 2010, 04:30:39 PM
Yes I would like to do it out loud right here.

The one in the link says 24 volt not 12?

Title: Re: Timed delay relays
Post by: James77MCI8 on December 07, 2010, 05:51:37 PM
I threw the 12 volt version in there because I did not know what your coach was
Title: Re: Timed delay relays
Post by: Sean on December 07, 2010, 06:46:39 PM
That seems like taking a problem that requires a $10 timer and a $2 relay to solve, and throwing an $80 PLC at it.

I tend to favor the cheaper and simpler solutions to these sorts of problems myself.  Also, as I have already written, I prefer solutions that do not use any power other than when they are operating, which would rule out most PLCs in general.

You ought to be able to do this for $15-$25 in parts, with no programming required.  FWIW.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: Timed delay relays
Post by: Joe Camper on December 07, 2010, 10:01:19 PM
You are absolutely correct something less complicated would also not require a computer programmer either.

You see, I have often seen and was under the impression that when you engineer something for a Prevo you take the simplest of processes and try to complicate them as much as you can.

The longer I own it the harder I have to fight off these and other similar notions  ;D

Thank you for the pinch.
Title: Re: Timed delay relays
Post by: JWallin on December 08, 2010, 12:01:33 PM
you could always just use a regular toilet
Title: Re: Timed delay relays
Post by: James77MCI8 on December 08, 2010, 05:36:12 PM
Programming is required. You do it by hard wiring relays and timers. So do it already Sean>
Title: Re: Timed delay relays
Post by: Joe Camper on December 10, 2010, 02:37:26 AM
JW this is a rear toilet it is at the back of the bus nowhere near the holding tank. It not only has to grind it has to pump 10 ft forward.

That said, after owning one I would prefer it even if it were over the tanks for the performance it provides keeping everything completely liquid in the tank.

I have a bunch of friends with professional conversions and can tell you from experience the Headhunter toilets..........they are north of 2 grand for a new one and this Raritan marine toilet I just repaired is 1500 for a new one.


Having to spend a little more for this expensive accessory for its flushing convienience is AOK with me.