Momentary button and fog lamps.
Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=9395
Printed Date: June 02, 2024 at 12:24 AM
Topic: Momentary button and fog lamps.
Posted By: pipes
Subject: Momentary button and fog lamps.
Date Posted: February 11, 2003 at 6:02 PM
I want it to be pushed once to turn them on and pushed again to turn them off. The way the switch works is it has three wires. When the ground is connected and one of the other wires is used the LED on the switch lights constantly and the when the other wire is used it lights when pressed and held and goes off when released. I want the LED to come on while the lamps are on and go off when there off. How would this be accomplished? I have looked at the diagram on the12volt but have some issues with it. Thanks for any help Sorry if it doesn't make much sense or is in one sentence.
Replies:
Posted By: pipes
Date Posted: February 12, 2003 at 3:38 PM
Disregard the above. I got the LED fixed but need to figure out how to make the relay stay on once the momentary button is pushed and then have the relay turn off when pushed again. How would this be accomplished, it's driving me nuts! Is the momentary to constant diagram what I need, if so can some one explain it to me. Thanks.
Posted By: pipes
Date Posted: February 12, 2003 at 6:09 PM
Well I know I need a set/reset logic circuit, question is how to I build one and what do I need.
Posted By: cruzinlow66
Date Posted: February 12, 2003 at 7:40 PM
A logic circuit sounds like overkill for what you need it for. Do you have a switch that you just have to use, or can you use something else? Radio Shack and many other parts suppliers have push on/ push off switches or push buttons, however not all of them have built in LED indicators. Another option may be a latching relay. You can wire it so when you push the button with the parking lights on, the fog lamps will turn on. When the parking lights are turned off, the fog lights will turn off and won't turn on again until you push the button. There are quite a few ways to go about it, depending on what you already have. Don.
Posted By: pipes
Date Posted: February 12, 2003 at 9:03 PM
I'm trying to recreate the factory setting using the factory switch which is momentary, I want to be able to turn the lights on and off when ever wish. The only way I know of is a set/reset logic switch. I just need to know how to make one, overkill or not.
Posted By: TomEllis
Date Posted: February 14, 2003 at 3:12 PM
I found a web site that describes something similar to what you want. Go to: https://www.tfs.net/~petek/autoelec/simple/togrel.htm I think this is what you are looking for. Tom
Posted By: pipes
Date Posted: February 14, 2003 at 3:41 PM
If I could make out the diagram it sounds like just what I need, I understand how things work but those diagrams boggle my mind. Where would I get DPDT relay anyway. Where would I find one of those latching relays that cost $60 bucks? There must be a way to accomplish this with a series of relays but I have yet to figure it out. I have however made a circuit that turns the lights on and stay on with one push, but they don't turn off. I need to find a way to break the ground temporarily using the same switch that turned it on. Any thoughts.
Posted By: TomEllis
Date Posted: February 14, 2003 at 4:01 PM
I found a place to purchase the latching relay. go to: https://www.watsons-streetworks.com/brake_switches.html About half way down the page is the relay. The othe way to make the circuit above work with the automotive relays is to put two relay coils in paralell with the transistor output. this allows two relays to act as a dpdt relay. Tom
Posted By: pipes
Date Posted: February 26, 2003 at 1:02 PM
How would building one be accomplished using standard 30amp relays. Really need help.
Posted By: the12volt
Date Posted: February 26, 2003 at 1:45 PM
The following is a latch engaged by a momentary pulse that will stay engaged until power or ground is interrupted on the latch (relay shown on the right in the diagram): https://www.the12volt.com/relays/page5.asp#mtc Here's another example of a latch using SPDT relays. https://www.the12volt.com/relays/page2.asp#psk You can also purchase latching relays from your local electronics supplier or on line here: https://www.goodmancomponents.com/products/-------------  the12volt • Support the12volt.com
Posted By: pipes
Date Posted: February 26, 2003 at 1:45 PM
I can get the DPDT relay but I know there must be a way to do it with regular relays,like the momentary to constant diagram. It says the ground can be removed with another relay but I don't know how. Remember I want to use only one momentary switch.
Posted By: jrilla
Date Posted: February 26, 2003 at 1:47 PM
OK so I wrote this at the same time as the12volt wrote his so I editted it a little:
"Correct me if I am wrong, but I think it is technically imposiible to make a standard 30 amp relay into a mechanically latched relay, since the mechanical latching relays use a locking clip to hold the contact in its energized position even after the coil is de-energized. Sorry if i am being too technical, but if you are interested in setting up some standard relays so that they will latch electronically, then this is quite easy actually."
After looking at the links that the12volt posted, If you still need any help customizing a relay setup for your project I would be happy to help: Even if you dont need help I would like to see what I can come up with.
Let me know what you need to do and I can draw you up a diagram. You will need to have a trigger that will latch the setup and then a trigger to unlatch the setup, just as you need with a mechanically latching relay.
-------------
J Rilla
Owner/Installer
Posted By: pipes
Date Posted: February 26, 2003 at 1:53 PM
What I need to do is press a momentary switch to turn fog lights on and press it again to turn them off. As the12volt said the momentary to constant works but getting the lights to turn off pressing the button again is the hard part. Hope this makes sense.
Posted By: jrilla
Date Posted: February 26, 2003 at 2:08 PM
I think I have something that will work, but I need to know how you have it setup right now. I need to know how your fog lights are set up, well actually ho wthey are triggered and anything else you can think of.
I will start to draw this up and hopefully you will have gotten back to me so I can verify it will work first
-------------
J Rilla
Owner/Installer
Posted By: the12volt
Date Posted: February 26, 2003 at 2:53 PM
Add two more relays to the momentary to constant setup I mentioned above. On the first additional relay connect the output of the momentary switch to terminal 30, connect terminal 87a to the trigger to engage the latch, and connect terminal 87 to terminal 85 of the second additional relay. The coil of the first additonal relay needs to be energized when the latch is engaged. Connect the ground shown on the latch to terminal 87a and ground to terminal 30. Connect terminal 86 of the second additonal relay to either the output of the latched relay or to 12V+. When you first hit the momentary switch, the latch will engage. When you hit the switch a second time, the ground will be broken on the latch and disengage. If this is unclear, let me know and I'll draw a diagram sometime this evening and post it here. ------------- the12volt • Support the12volt.com
Posted By: AverageJoe
Date Posted: February 26, 2003 at 3:52 PM
Hi, new to this site. I have a question. I know this can be done using a mechanical latching relay, but i don't want to go that route. How can I do it with standard relays? Could a 3rd relay be added to the Constant to Momentary Output scheme to make this work?
Posted By: pipes
Date Posted: February 26, 2003 at 4:44 PM
I'll give it a go but if you could draw up a daigram that would be muchly appreciated.
I have them setup where the power comes from the battery to a switch which I want to replace with the factory momentary switch (don't like the cheap one that came with them) then the accesory wire goes to the lamps and then to ground, your typical setup. I am doing this to replace the lamps with factory ones if you wondered. Hope thats enough.
Posted By: pipes
Date Posted: February 26, 2003 at 4:48 PM
Well the mechanical relay is the best route but believe me they are expensive and nearly impossible to find. I'm trying to do exactly what you are and am almost finished thanks to the12volt, I'll let you know when I'm done.
Posted By: the12volt
Date Posted: February 26, 2003 at 6:03 PM
Here's what I had in mind using only SPDT relays. Try it and post your results. 
------------- the12volt • Support the12volt.com
Posted By: pipes
Date Posted: February 26, 2003 at 7:11 PM
That's not going to melt my switch is it? I tried the momentary to constant setup and with the switch ground and smoke came from it, it still works (thankfully). I will give it a try though. Have to get one more relay tomorrow.
Posted By: the12volt
Date Posted: February 26, 2003 at 7:20 PM
No, not at all. If your switch smoked, you definitely have something connected where it shouldn't be. Double check your configuration (wiring and connections) with my diagram, paying close attention to each terminal and lead connected to it. ------------- the12volt • Support the12volt.com
Posted By: pipes
Date Posted: February 26, 2003 at 8:04 PM
Are you going to be putting this in the special application section of relays? Just wondered cause it may help a few people. Just a thought 
Posted By: the12volt
Date Posted: February 26, 2003 at 8:14 PM
Yes, eventually I'll add that one and a few more. If I'm up to it and have the time, I'll add them this weekend. ------------- the12volt • Support the12volt.com
Posted By: pipes
Date Posted: February 27, 2003 at 2:24 PM
It didn't work but have a question, the relays I have output from both 87 and 87a when the coil is energized, is this where the problem is?
Posted By: the12volt
Date Posted: February 27, 2003 at 2:32 PM
You should only have output on one terminal at a time. Double check your connections. If I have time this evening, I'll bench test my configuration and let you know what I get. BTW, are you using SPDT relays? Make sure each relay has five terminals and that they are marked as I have shown in my diagram. If not, it will never work. ------------- the12volt • Support the12volt.com
Posted By: pipes
Date Posted: February 27, 2003 at 2:45 PM
yes there is 5 terminals but 87 and 87a are both normally open. If this is the case what can I do I can't find any others then those type.
Posted By: jrilla
Date Posted: February 27, 2003 at 6:19 PM
I was looking that diagram over and it looks like it will have the same problem that the setup that I rigged up. I noticed that the momentary switch must be pressed for only a split second. any longer and the relays just chattered back and forth. I think this would not be a problem if you had a switch that snapped out the momentary connection instead of connecting the wires as long as the user holds down the switch. I will have to bench test this diagram too.
-------------
J Rilla
Owner/Installer
Posted By: the12volt
Date Posted: February 27, 2003 at 8:22 PM
J Rilla, I see I have you thinking ;) Yes, as I have it drawn it requires a very short pulse. By adding two more relays, a diode, a capacitor, and small resistor it works with long pulses and does not chatter back and forth, however as I understand it, the challenge is to only use SPDT relays :) Sorry pipes, I don't have time to play with this tonight, maybe sometime this weekend. BTW, the price of a 1 latching relay and 1 SPDT relay is cheaper than 6 SPDT relays (and counting), smaller, and much less time consuming ;) ------------- the12volt • Support the12volt.com
Posted By: jrilla
Date Posted: February 27, 2003 at 8:42 PM
no smoke either
-------------
J Rilla
Owner/Installer
Posted By: pipes
Date Posted: February 28, 2003 at 8:25 AM
If I could find a mechanical latching relay I'd be set but no one seems to sell them or even know what I'm talking about for that matter. This is quite the challenge though.
Posted By: jrilla
Date Posted: February 28, 2003 at 8:27 AM
https://cgi.ebay.com/dll?ViewItem&item=3009809642&category=1498
-------------
J Rilla
Owner/Installer
Posted By: pipes
Date Posted: February 28, 2003 at 10:50 AM
That would be great but I don't trust ebay pruchases. And I live in Canada so any other stores I could try.
Posted By: jrilla
Date Posted: February 28, 2003 at 12:06 PM
the guy selling this is a guy that spends a lot of time on this website. Where does this fear of ebay come from? it isnt like you are betting the house on it. You can get one for 20 or 30 bucks from an online store if you are not interested in saving money on ebay.
-------------
J Rilla
Owner/Installer
Posted By: MCubed45
Date Posted: March 01, 2003 at 4:10 AM
hey guys, i'm new here but this diagram by go2pac i found in another thread seems to be the most effective. only 4 relays and 1 diode. you don't count that other one in the top right b/c that's more for having a secondary means of activating the device. just substitue your lights for the radio. the other application (which i am using this setup for) is to use a single channel on a remote to control a motor in two directions (windows, mirrors, seats... those seem to be the ones i found people asking about). i will be controlling my power widows. most alarm shops will tell you that you need two channels if you want to be able to move in two directions. this allows you to do it with one.
essentially in the initial state you have no output. when a signal is sent you have a positive 12v output which remains even if the signal is kept constant. in pipes case this is the equivalent of holding the button down. then when released it continues to send a +12v signal. the next time the signal is sent (button held down) there is no ouput immediately and there continues to be no output while the signal is present and after the signal has ceased. this returns the relays to their initial state. this does exactly what pipes wanted and does not require an extremely brief signal. in my case it allows me to press and hold the button on my remote as long as i want the windows to move down. they will then stop when i release the button. the next time i press and hold the buttonn as long as i want them to move up. and so on and so on. in my case i would also use an additional relay hooked up as follows: 86 output from 'latching relay'. 85 ground. 30 (-) input from alarm channel. 87 output to 'down' window relay. 87a output to 'up' window relay. the 'up' and 'down' widow relays are used for sending current in different directions to the window motors (one direction makes the windows go up, the other goes down). anyways, hope that helped. i have not built this latching relay yet but i have carefully gone over the schematic and it does not have the problem of alternating between states when a continuous signal is sent. special thanks to go2pac for the diagram! it's posted in several threads i believe... https://www.go2pac.com/misc/miscdiagrams/latchrelay.pdf
Posted By: MCubed45
Date Posted: March 01, 2003 at 4:16 AM
here, thought it'd be easier to post the pic instead of just the pdf.
go2pac, you kick ass! haha idk how many people would tell you it's not possible to use a single channel to control windows i two directions. can't wait to hook mine up! :) https://www.go2pac.com/misc/miscdiagrams/latchrelay.gif
Posted By: jrilla
Date Posted: March 01, 2003 at 10:08 AM
Yeah that is a pretty slick setup. Worked like a charm when I bench tested it. I only neede one diode for it to work though.
-------------
J Rilla
Owner/Installer
Posted By: MCubed45
Date Posted: March 01, 2003 at 10:59 AM
yea you only need the diode in the center bottom if you're using the (-)doorlock input (or any other source) as a bypass to automatically turn off the device. otherwise sending a signal through the (-) 2nd channel lead when the device is on would trigger the doorlock at the same time. the diode in the top right would only be used if you were using the relay in the top right in conjunction with a second SPST switch.
Posted By: the12volt
Date Posted: March 01, 2003 at 1:26 PM
I played with mine and came up with what appears to be the same basic configuration as go2pac supplied. Yes, only one diode is needed to prevent the latch from re-engaging. The other one shown in my diagram isn't needed, but is used to prevent the potential voltage spike that may occur when the coil field collapses and could/should be added to each of the other relays shown without them. The output from the switch can stay on for as long as you like without any chance of the relays chattering back and forth. However, it's still quicker, cheeper, and easier to use a latching relay and one SPDT relay ;) BTW, it's been added to the special applications page for future reference. 
------------- the12volt • Support the12volt.com
Posted By: the12volt
Date Posted: March 01, 2003 at 2:06 PM
To make it work without a diode at all, simply remove the diode shown on the purple wire and connect terminal 87a (where the purple wire is connected on the first relay) to terminal 85 of the additional relay, connect terminal 86 of the additional relay to ground, connect terminal 87 of the additional relay to a fused 12V+ and connect terminal 30 of the additional relay to terminal 85 of the second to last relay and terminal 87 of the last relay. 
------------- the12volt • Support the12volt.com
Posted By: MCubed45
Date Posted: March 03, 2003 at 9:43 AM
[QUOTE=the12volt] However, it's still quicker, cheeper, and easier to use a latching relay and one SPDT relay ;)
hey 12volt, about how much does a latching relay run and from where? just wonderin b/c radioshack didn't have any.. also would using digital logic come out any cheaper? i actually asked one've my EE professor's about which's the simplest/easiest way to do this and he's supposed to get back to me
Posted By: the12volt
Date Posted: March 03, 2003 at 11:06 AM
I get mine from a local electronics distributor (not Radio Shack). You can find them online. Search for Siemens, Aromat, Potter & Brumfield, etc. latching relays. Here's one that has a couple for under a $1.00 each near the bottom of the page: https://www.hosfelt.com/en-us/dept_111.html ------------- the12volt • Support the12volt.com
Posted By: pipes
Date Posted: March 11, 2003 at 7:33 PM
Well thanks for all the help but after much looking I found a Mechanical Latching relay and my problems have been solved, in fact I went to this one place and the guy (wearing a leather suit!) said they stopped making them 20 years ago, I thought to myself yeah as well as that suit :) But I found a store that has everything you could imagine. Just thought I'd let you all know.
|
