Fog-Lamp ECU-Relay WHAT?!?!?

[PSUViper]

Hi Everyone - please help me out.

I'm trying to use a temporary-pulse ground-control switch (A fog-lamp switch) to activate an ECM which will then send power to a relay which in turn sends power to the fog-lamps.

I have NO IDEA where to find this simple of an ECU - something that will read a single, ground current pulse and use it to activate OR DEACTIVATE a separate circuit.

That, or I need an electro-mechanical latching relay that can use the same source-switch to open OR close itself.

I'm stuck - please help.

Jeffrey Knapp
WyoTech Automotive Technical Training School

http://www.JeffreyStephen.com

 

[iamyo]

When you say ECU, you mean Electronic control module? I find is too much just to control one relay. From my point of view the best solution would be to use a bistable relay i.e. from NEC as you said.

I hope helps

 

[EvilJeb]

I've been working on a similar problem for a year or so, on and off. Sometimes I forget about it for a few months, but then I start wondering again, just what is a cost-effective and reliable way to do this? I have a latching relay which unfortunately only operates from 9V positive, three terminals for controlling, on, off, and ground, but I want the same button to control both the on and the off function. So what do I do? Use a monostable such as the '221 to generate a pulse, controlled by a couple of flip flops, one to hold the state and one to debounce the switch, and after the monostable put a transistor to drive the relay? Or is there a way to make a discrete circuit do this same fucntion with only half the parts? I have 20 of these relays, and want to duplicate the circuit for all, so that's why I keep wondering what is the simplest and cheapest? If I didn't have the relays already, perhaps I would change their specification to better match the logic circuit.

 

[carnage1]

the "ECU" you are after is a flip-flop, we use them all the time with our pnumatics. every pulse switches the output from high to low and vice versa, most flip-flops have both Q and Qnot outputs so you can select by how you wire it if it will start on or off. use an hc series cmos 3-18v logic range.