Timer Switch Questions: Answers & Solutions

[MES]

I am trying to figure a way to hook up a timer to my pellet stove. The control board of the stove has an "on" button and a separate "off" button. The on button is a push button switch. My question is: is there a programmable timer that closes a circuit for a second and releases the switch like some one pushed the button? I was considering a programmable thermostat with a timer built in. Does the timer operate by completing the circuit and releasing? Or does it switch on and keep the circuit closed? Or am I way off and it is sending a small amount of electricity thru the wire and it’s not a switch. Does this project even sound possible? I don’t really want to take the stove apart if it’s not worth doing.

 

[denni89627]

Allen Bradley makes excellent timer relays that you can do this with. They have many functions and even an adjustable dial with adjustable time units so you can set the timer anywhere from under a second to a couple of days. They are bulletproof. I have retro fitted many of them into use for antique elevator wye delta transfer timers. Never had a problem.

 

[MES]

Ok thank you very much for the info. I’m going to dig a little deeper to check how much voltage is running to the switch just to get an idea what I am working with. The last thing i want to do is fry all the electrical components.

 

[MES]

I haven't really messed with it because I have been busy but its found its way back to the top of the to do list so I am back to looking. I was thinking to use a thermostat for an hvac system that would control when the unit came on. I am going to get one and test to see how the thermostat acts like a switch. I know that i need something that completes a circuit for a brief moment. If I find one ill let you know.

 

[sparkey]

the only issue that i can see with what you are trying to do is that most thermostats are held contacts, so when they're on its held closed. it sounds to me like your stove has a momentary contact PB for the 'ON'. that being said, your control circuit still needs power, so there must be a holding circuit that is bypassing the 'ON' PB.

if you want the thermostat on it, what i would do, is bypass/jumper out the 'ON' PB and install the thermostat before the holding circuit by wiring it directly after the 'OFF' PB.

       ORIGINAL 

-----------------------___-----x------___-------x-----------(holding coil)-----
                     nc 'off'  |    no 'on'     | 
                               |-------||-------|
                                  no  'holding'

          TO THIS         |--------____--------|
         |     'thermostat'   |
----___--x   x------___-------x-----------(holding coil)-----
  nc 'off'   |     no 'on'    | 
             |-------||-------|
                  no 'holding'
           OR THIS                                    jumper
                                  |---------|
------___--------------___-----x--x---___---x---x-----------(holding coil)-----
  'thermostat'       nc 'off'  |    no 'on'     | 
                               |-------||-------|
                                  no  'holding'

 

[MES]

I will try this and see if it works, Thanks!