Head Pump switch/timer

[MikeP]

Another thing I've been thinking about...

Our Galley Maid head pumps are activated by a push-button that has to be held down for however long you want it to flush. We usually flush for 6-10 seconds. Galley Maid makes a switch with an 8 second timer which I would like to install in all three heads BUT they are $158 EACH!!!!!!!

I figure it can't be that hard to make the timer circuit myself. Well, except for the part where I have no idea how to do that!

So...how do I do that?

[Brian Degulis]

They're switch is not an electric timer as far as I can tell it's a push button with a little air chamber that keeps the button from springing off imediatly. In other words it has spring working againest a vacum. There is a screw in the back to adjust the on time by putting more or less pressure on the spring.

The problem with making a timer is the 32V thing. I would imagine you could find a rotary mechanical timer that you would simply turn instead of pushing a button.

Brian

[Angela]

Mike,

Dave has a brand new one of these switches. He may still have it. He had one; that's won't get your whole project done, but it'll get one done for a whole lot less than $150!

http://www.samsmarine.com/forums/showthread.php?t=8792

[MikeP]

Thanks Ang, I'll contact Dave. That's ONE!

I had contacted GM re the switch, I wonder if Raz has them cheaper? I'll contact them and find out.

Brian - thanks, I had assumed there was some sort of $2 electronic control incorporated in the switch that did the timing function and figured I could get it from Mouser or whoever and connect it appropriately.

[DAlter]

Mike,

Brian is correct. Take the switch out of the wall and there is a small adjusting screw on the back you can turn to increase or decrease the time. If that doesn't work, just hold the switch in and count to five then let go and that should give you your eight seconds.

[MikeP]

The switches don't look anything like the one in the pic on Angela's link and it feels just like a regular spring-loaded momentary on push button. But I've never pulled it or looked from underneath to see the back side.

The front of the switch says "FLUSH UNTIL SOLIDS HAVE CLEARED FOR 5 SECONDS," which sounds totally manual to me. The 3/4 full red light for the waste tank is incorporated into the switch plate.

I guess I'll have to wait until I'm back on the boat in Sep to be sure I don't spend money for nothing! Here's a pic of the switch plate. It's a HUGE blowup from a pic of the whole head so it's not too clear.

[REBrueckner]

Here are three ideas:

My 12 volt (Raritan Crown) heads came equipped with a timer of the type you are describing....Mine are 12 volt, but the solenoid doesn't care what the voltage is on the heavy main (toilet) terminals...its the power rating that limits....a 32 volt toilet likely has light current compared with a 12 volt anyway...so you could use a "12volt solenoid" and 12volt timer if you have that voltage conveniently available at the location required...just hook up the 32 volt battery supply to one of the big solenoid terminals, the 32 volt toilet lead to the other....and use 12 volt to power the solenoid small terminals and timer....
I checked the Raritan Engineering website and saw solenoids, but not the timers....solenoids were $39.50....did not see a voltage, likely 12.

I wonder if an auto windshield wiper "timer" would do the job...the type on the steerinf column that activates the wipers.....If the solenoid for the toilet required, say 2 amps at 12 volts to activate, and the power rating for the windshield wiper was adequate, that might be an inexpensive solution...an auto parts store would be a place to start,,

Another approach would be to go to an electronics store and say " I need to power a solenoid that takes 2 amps at 32 volts (or whatever it is) ...What kind of timers do you have that would alow me to apply that power for about 7 to ten seconds???

[DAlter]

Mike,

I misunderstood, or misread your first comments about the switch being manual and assumed you had the same switch as mine, which is automatic. However, after looking at your photo, the switch is different then mine. I have a larger, green colored one....so you may not be able to adjust it from the back as I suggested.