2 channel timer for egg turner?

[wynn4578]

Does anyone know where to find a 2 channel timer for use on an egg turner. My plan is to run each channel to control polarity to a dc motor and limit switches to stop rotation (not my design). The designs I've seen like this use 2 timers offset in 2 hour increments. I used to have a reptile timer that did this but it was an analog timer. I would prefer if it were mountable just to keep things clean but any 2 channel timer would work.

 

[Daedalus62]

Hi wynn4578,

Read in your other thread, you're planning on using raspberry pi as an incubator controller... How about running stepper-motor(s) on your egg turner(s)?...

Please stop me if I'm saying something dumb

, but...

Being able to control timming, speed, direction and angle of rotation on a stepper-motor with a microcontroller (raspberry pi), will make things much simpler... Meaning, you can dispense with extra timers, limit switches, polarity inverters, extra wiring, etc, etc...

Just a thought

...

Cheers

 

[wynn4578]

The pi is going to be a future implementation but i did find a solution for now. In case anyone else is interested and aren't planning on using an Arduino or a Pi as a controller, you can get a digital twin delay timer on Amazon for 26 bucks. In my case it eliminates the dual timers and the relays. Simplifies and cleans everything up. http://www.amazon.com/gp/product/B008KV65MS/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

[wynn4578]

Just a quick update this timer would probably be better http://www.amazon.com/Sestos-Digita...ie=UTF8&qid=1431146877&sr=8-2&keywords=sestos It has 2 channels and four cycles instead of 2.

 

[gpop1]

The relays work but can be a little difficult to program. You will also need a signal to start and reset the timer. Most people using this type of timer will be using a motor that only turns one direction and the mechanics reverse the rotation.

Now if your design calls for a reversible motor you will need a alternating relay. Every time the relay is called the output will change from a to b then back to b to a. Also you will need 2 standard relays with the commons linked to the motor. Both relays should have the negative on the n/c contact then and the positive on the normally open contact.

The timer will turn on and make the alternating relay start. The alternating relay will operate either A or B relay. e.g A relay closes and sends positive to motor. B relay is not closed so its already sending negative to motor. Motor turns for set time or until micro switch closes and send reset to timer......... Timer stops and goes back to count down. Next cycle alternating reverses and motor runs backwards. (link both switchs so they reset the timer). A single timer with reset will work fine. (most digitals can be programmed 50 different ways so they can be single/dual etc)

 

[gpop1]

consider 2 mechanical panel mount timers it easier and cheaper. Just 2 timers and 2 micro switchs

 

[wynn4578]

This is he concept for my current wiring diagram.

 

[gpop1]

This is he concept for my current wiring diagram.

it doesn't make sense to me. Unless im reading it wrong I think the limit switch will be a problem. im not saying its wrong it just looks like theres a easier way.
If I had to do this then I would try this




motor will run till the limit switch breaks the line,
relay will toggle every 2hrs (programmable)
belt and braces add a overrun shut down or small fuse that will blow after motor is locked (depends on motor size)
most of the problems due to a power cut will take care of themselfs
no way you can program the timer relay to short circuit as its using only one set of contacts.

 

[gpop1]

forgot to add most timer relays will have buttons on the front so you can over-ride the timer to make the turner start (e.g reset the timer or move to timer 2)

 

[wynn4578]

Yours is actually very similar to my first design. I went this route because I couldn't figure out a way to add a manual for/rev. without causing a backfeed. I may be wrong (I won't receive my timer unit until next Thursday) but I don't think it has a manual switch. I sent the first timer I posted back because it was A,B but there was no delay between the 2 and my plan is to set up a screw type shaft for the turner. The new timer is A C B D. A and B are built in relays (SPDT) 1 and 2. C and D are no output timers between A and B. So A would be set to kick on x seconds and limit out. C would kick on (no output) for 1 hour. B would kick on x seconds and limit out. D would kick on (no output) for 1 hour. This timer has both single shot and continuous cycle. I went with a screw type shaft because I plan on mounting the motor outside the incubator. With all that being said if it turn out this new timer does have a manual switch, life becomes much easier. lol.