×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

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

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

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

(OP)
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
www.JeffreyStephen.com

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

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

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

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.

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

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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources