Relay for Momentary Switch???

[mwr1964]

I installed some driving lights in my wife's car and I ordered the actual driving light switch from GM for this car. The switch is 12 vdc momentary.
So I need some type of relay that will close a 12 vdc coil once a pulse from the switch is received and open the coil when it is pushed again.
It also needs to be strong enough to power the driving lights, which are each 55 watts at 12 vdc.
Can anyone help I would really like to put the actual switch in that belongs to the car for the driving lights.
Thanks in advance.

 

[Reloadron]

What you want is a latching circuit that can be latched and unlatched by pushing a single Normally Open push button momentary switch. The circuit that can be found here is a good candidate for the task. The Out to Load would drive your relay. Personally I would use an automotive relay like an Omron part number R51-1D40-12F which is a SPST-NO relay more than capable of handling the lamps. Automotive relays are built for the application you have.

Another option would be the use of a PIC chip which would be programmed to handle the task but personally I would go the route above.

Additionally make sure the added circuit is fused!

Hope that helps...
Ron

 

[ericgibbs]

hi Ron,
That latching circuits works OK.
As a side issue, its a circuit that was first published in a Motorola semiconductor manual during the 1970's.

I find it amusing that the guy who has 'redrawn' the circuit claims to be the designer and has claimed copyright .

 

[AllVol]

I find it amusing that the guy who has 'redrawn' the circuit claims to be the designer and has claimed copyright .

That is odd, for I have had the attached schematic in my circuits library for some few years. Don't remember where I got it, but it was public domain, I'm sure.

 

[ericgibbs]

That is odd, for I have had the attached schematic in my circuits library for some few years. Don't remember where I got it, but it was public domain, I'm sure.

hi,
Thats the one, using 4069's.

Hope 2010 is going well for you.

 

[Reloadron]

hi Ron,
That latching circuits works OK.
As a side issue, its a circuit that was first published in a Motorola semiconductor manual during the 1970's.

I find it amusing that the guy who has 'redrawn' the circuit claims to be the designer and has claimed copyright .

Yeah, I sort of found that peculiar myself but just linked to it as it was. I have seen other circuits by the same author with copyright plastered on it. Many circuits like this are just plain simple generic circuits so I never really got the copyright thing? Suppose I draw out the transistor equivalent of a 7400 NAND gate as a Gated RS Latch. Can I place Copyright on it with my name? I would think not. Anyway that is why I just link to things like that. Beats the hell out of me.

Ron

 

[AllVol]

hi,

Hope 2010 is going well for you.

Too cold and snowy... can't get on the golf course.

I'll just stay here and make life miserable for everyone.

 

[mwr1964]

Thanks I found the Relay online, but the part number you gave is not mage by Omron. Here is the link. NTE Electronics, Inc. - R51-1D40-12F - Allied Electronics Also in detail let me get this right so I don't screw it up. I supply 12 vdc to the switch from the battery or what ever and ground the switch. Then send the 12 vdc to the relay which close the coil when I press the switch the first time and then again opens the circuit. The switch is also illuminated I suppose the power I send out to the driving lights, from the relay, I could send to that terminal on the switch for illuminating the switch when the lights are on.

 

[Reloadron]

Using the circuit I linked to in the beginning S1 would be your switch. S1 would toggle the relay which is connected to the MOSFET transistor On & Off with each press of the button. ALLVOLT also presented another circuit that would work for this application. There are several ways to do it. The circuit I linked to has your PB switch connected to pin 1 of the opamp and the junction of R2 & C1.

The relay was funny as I found it in my Allied Catalog. Maybe I should drag home a newer catalog? The one I used is an 06 catalog. That same item or similar could be had at likely any auto parts store.

Ron

 

[Mikebits]

You can buy latching relays. **broken link removed**