Newbie needs some help

[rtm038]

I'm new to this site, so let me first say hello to you all. Now, here's my question. In my 2006 Ford F-350, the heated seats are activated by a push-on/push-off switch. The problem with this set-up is that if the seats are "ON" when the truck is shut off, they will turn back "ON" when the truck is restarted. Basically, I'd like to design a circuit that would use a normally open momentary pushbutton switch to control a 30-amp relay in the following manner:

1. Push button once- relay turns on (seat heaters turn "ON")
2. Push button again- relay turns off (seat heaters turn "OFF")
3. Remove electrical supply anytime seat heaters are "NO" (i.e. turn truck off)- relay turns off and the seat heaters stay off until the button is pushed again

Any help would be greatly appreciated.

Thanks
Ryan

 

[omnyx]

hey. I'll try to help but please clarify number 3.
you want the push button to turn off anytime the heaters are on?
but isn't that just what number 2. is saying? or maybe you have an alternative way of turning the heat on.

 

[things]

latching relay? push button once, relay latches and stays latched untill the button is pushed again?

 

[jpanhalt]

Look up magnetic/relay starters. They are used on lots of machine tools with switches that provide only momentary contacts. Basically, you have a relay with the coil in series with a set of N.O. contacts. Thus, once the coil is energized, it stays energized. But once the circuit is broken, you must hit the "on" switch to start it again. If there is power interruption, as when you turn that monster off, the relay opens so the circuit will not start until you tell it to start. John

 

[rtm038]

latching relay? push button once, relay latches and stays latched untill the button is pushed again?

That's what I’ve thought about using, but haven't been able to find a whole lot of information on them.

Tell me if I'm understanding how a latching relay it works:
1. Press & release the normally open momentary pushbutton switch once. This will momentary apply 12+VDC to the relay coil and “complete” the “load” supplying circuit.
2. Press & release the normally open momentary pushbutton switch again. This will momentary apply 12+VDC to relay coil and “break” the “load” supplying circuit.

 

[rtm038]

hey. I'll try to help but please clarify number 3.
you want the push button to turn off anytime the heaters are on?
but isn't that just what number 2. is saying? or maybe you have an alternative way of turning the heat on.

Basically I want to make like this:

1. Push & release button= seat heaters come
2. Push & release button again= seat heater shut off
3. Turn the truck off= seat heaters automatically turn off and will not come back on until the truck is restarted AND the button is pressed again.

 

[rtm038]

I just found this circuit that uses a single transistor to toggle a relay "on" & "off". According to the author, while the schematic shows (2) N/O momentary switches being used, the circuit will still work using only 1. Does anyone think this will work for my application?