need to make a pulsed signal steady?
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=113180
Printed Date: May 15, 2024 at 8:17 PM
Topic: need to make a pulsed signal steady?
Posted By: tanamu
Subject: need to make a pulsed signal steady?
Date Posted: April 15, 2009 at 8:03 PM
Hey all,
I have a 93 Nissan 240sx, and the door chime is pretty much the most annoying thing in the world. I have therefore replaced it with one from a VW that I liked, but the problem is that the VW's door chime requires a constant 12v signal to stay on, whereas the stock Nissan chime is just an electric bell, so it takes a pulsed (square wave I guess) signal.
The problem is I'm not sure how to turn that pulsed signal (probably around 1-2 Hz) into a steady 12v that will work with the new chime. I have tried using a pair of big capacitors, but they tend to make the chime stay on wayyyy too long, and one cap isn't enough. Also tried a 555 timer but it didn't really work either. So I decided to ask here and see if you guys have any ideas. :)
Thanks.
Replies:
Posted By: i am an idiot
Date Posted: April 15, 2009 at 8:24 PM
| Pulsed to Steady Output | If you have cornering lights and want them to come on only when your turn signal is on and you do not have a steady output, use the following for each side. This will give you a steady output while the turn signal is on. Increasing the size of the capacitor will give you a longer output if needed.
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Posted By: tanamu
Date Posted: April 16, 2009 at 12:05 AM
Hm, you know I think I found that a long time ago when I first set out to do this.. but I was a little hesitant to try it because my relays tend to be pretty loud, and I don't really want to listen to the clicking every time the thing pulses.. but maybe I'll just go find a quieter one. :P
Thanks.
Posted By: KPierson
Date Posted: April 16, 2009 at 5:05 AM
Pick up a reed relay - they are silent. You will have to tweak your values with a reed relay though because their coils require drastically less current to stay energized (so theoretically you should be able to use a much smaller cap).
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Kevin Pierson
Posted By: i am an idiot
Date Posted: April 16, 2009 at 6:05 AM
The relay will only click when it engages and will not click again until it disengages. Remember the pulses have been converted to a non-pulsed output. It will not click with each pulse of the input.
Posted By: profuse007
Date Posted: April 16, 2009 at 9:11 AM
used that same setup, not that clean but it works. the capacitor i got was pretty huge, ~0.5"dia-by-1.5".
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Houston,TX
"The two most common elements in the universe are H+ and stupidity" (Ellison).
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