Programmable Timer

[Kool Parts]

There are lots of guys on this board designing, and building their own electronic boards and even cnc machines. I am not one of them I am hoping that in your travels though all of the electronic catalog's you have come across a "timer" like the one at the bott of the page in this link. (6LM70)

http://www.grainger.com/Grainger/wwg...se&CatPage=473

What I want is a programmable timer to turn on a motor (120 v 3amp) for so many min per hour, 24 hours a day for (at least) 14 days. Also 2 or 3 outputs would be helpful.
What I don't want is to pay $250 :frown: (cheap bastard) Normally grainger is higher than a cats back, so maybe its possible?
Thanks,
Gary

[philba]

Have you looked at Home Depot or Lowes? They have a number of timers that might fit your needs. The grainger ones didn't look that expensive (70 is not an unreasonable amount to pay for something like that).

[Al_The_Man]

I don't know what part of the US you in, but there is something used north of a certain latitude called a block heater timer for automobiles, You may be able to pick those up cheap, but I am not sure if you can program multiple cycles over 24hrs, you may have to check on individual features.
Al.

[Kool Parts]

philba,
Yes, I have tried all of the usual suspects. Kinda going in a different direction.
Actually the one in granigers is $253.00
Thanks,
Gary

[HayTay]

You may want to take a look at what James Larsson did to modify a used VCR into an automated cat feeder (Photos: From VCR to cat feeder). He took advantage of the programmable recording timer feature of the VCR. With a little ingenuity and some help from the CNCzone electronic gurus maybe this idea could be modified to control a TRIAC(?) (or three) that would in turn drive your 120V 3A motor(s). A used VCR and a few electronic components should be way less than $250.

Post your project if you decide to give it a try.

Have fun,

Harry

[Megahertz]

The surplus/salvage electronics store sells a coffee machine timer for $5.00. Here is the web link and some more details. The part number is MTC-3

http://www.allelectronics.com/cgi-bi...T-3&type=store

DIGITAL ON-TIMER

Digital timer from Mr. Coffee™. Small modular design, no brand name or logo. Ideal for use in any product that needs to be turned on automatically at a specific time. Operates on 120 Vac. Switch loads ups to 10 amps. Can be switched manually. White plastic face. 2.48" X 1.77", with four digit LED clock. Overall size: 2.48" X 2.17" X 1.88" deep behind face. 0.25" qc terminals. Easy to connect and operate. Includes instruction sheet.

[Kool Parts]

NICE work Megahertz
Well opon further inspection it just turns on once a day. but nice link none the less.
Thanks,
Gary

[Megahertz]

Kool Parts,

I read your original post again and I see you want to turn on every hour and you would like 2 or 3 outputs. The solution is easy. There are 24 hours in a day; so you should buy 72 timers (24 * 3) are hook them up in triples and delay the time of each group of three by one hour. 72 * $5 = $360. Think of how cheep that is for all that computing power!!! Plus, the hours of time it would take to program and syncronize those timers, Jolly Fun.

[One of Many]

There are several OEM's that make these along the same lines.

One ebay example

Another

Another

Programmable would be nice, but cheap could get you by on a few cycle timers all daisychained together to cover 60min with an adjustable on time. It would be continuous recycle, not shutting off on the 14th day.

DC

[Kool Parts]

Megahertz,

so you should buy 72 timers

That was the first thing one of the guys in the shop said! Of course there is a sump that needs cleaned.. And I'm going to ck out the cat feeder, I need one of those anyway
Gary

[Geof]

Buy a cheap battery powered wall clock. ($15.00)
Glue a little bar magnet to the minute hand. ($1.00)
Glue two magnetic reed switches to the face of the clock at the appropriate minutes spacing and make sure that when the magnet passes them they close and re-open. (2 x $5.00 or less)
Buy a latching relay with a 12 volt coil and contacts able to handle your load.($15.00 or maybe a bit more)
Buy a cheap 12volt 500milliamp DC wall plug transformer. ($10.00)
Connect transformer through reed switchs to latching relay; first switch closing latches relay on, second switch closing latches relay off.
Run whatever you want from the relay contacts.

I've done it, it works to within seconds every hour.

[davesaudio]

I wonder if what you want is in the capabilities of a lawn sprinkler timer?
between the zones and programmable times maybe....

or maybe put two cheap timers in series...