decreasing the pulse duration
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=116627
Printed Date: May 15, 2024 at 8:20 PM
Topic: decreasing the pulse duration
Posted By: aviator172
Subject: decreasing the pulse duration
Date Posted: September 30, 2009 at 10:35 AM
Hi,
I have a situation where my aftermarket alarm does not have a wire that is suitable for activating the OEM horn when I set the alarm because it came with a siren (which I don't like and will not be using). Instead, I will rely on the OEM horn for a siren.
(This particular alarm has a remote paging function and will notify me up to a considerable distance so the horn is not really necessary IMO, but it will give me an audible confirmation as I walk away from the Van that the alarm has indeed set).
Problem is, the one wire I found I can use has a full 1 second pulse duration.
So, when I arm the system, the horn blows a bit long for this.
Ideally, I would like for the horn to just "tap" (a very short, quick blast of about 1/3 to 1/2 second blast as I arm the system.
Is there a way to decrease the duration from 1 second to 1/2 a second (or so) on a wire?
thx
Replies:
Posted By: aviator172
Date Posted: September 30, 2009 at 10:44 AM
Posted By: tommy...
Date Posted: September 30, 2009 at 11:25 AM
What alarm system is it...? If it is a 2-way system...You normally get a confirmation chirp on the remote...What do you mean "suitable"...? What kind of car...? The public has become pretty numb to sirens and horns...But i think it is a VERY important part of your alarm...Why not use the siren...? The siren helps for the "not very good thief"... with a siren going off...They will most likely get the heck away from the car...! Almost all aftermarket alarms come with a siren...Most usually come with a horn output too...! If you could give a link for the install manual...? Ill peruse it while im home sick*cough*cough*...  ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: aviator172
Date Posted: September 30, 2009 at 11:35 AM
Hey Tommy,
It's a Carvox king eagle CV- 990 I think.
The remote does its thing, I just want the horn to burp once as a louder confirmation.
If someone attacks my Caravan, the factory alarm will go off (OEM horn) and I'll be notified via the pager so I'm not quite as concerned about a siren as I would be without the pager...but nonetheless, the Factory horn will be going off.
The siren sounds blasee and so run of the mill. It's almost boring. So, rather than hang it somewhere and deal with the wiring, I'm omitting it for the reason above.
I got it working, but I used the unsed "arm" wire instead. It works but the horn blows about half a second too long IMO. Intead of a "chirp"...it's a "beeeeeeeeeeeeeeeeep".
Posted By: howie ll
Date Posted: September 30, 2009 at 12:05 PM
Aviator, look to the relay section here for circuits, tommy, wish you better, aviator ref your last post, on certain Chryslers with resistive multiplex wiring, 200milliamps is not enough to overcome the resistance (s) you need e.g. on the locking system. If your unit only has two wires, it means a low current output signal is generated. If 6 wires, that means on-board relays and you're OK.
Posted By: aviator172
Date Posted: October 01, 2009 at 1:54 PM
Hmmmm ....noone ????
I have a situation where my aftermarket alarm does not have a wire that is suitable for activating the OEM horn when I set the alarm because it came with a siren (which I don't like and will not be using). Instead, I will rely on the OEM horn for a siren.
(This particular alarm has a remote paging function and will notify me up to a considerable distance so the horn is not really necessary IMO, but it will give me an audible confirmation as I walk away from the Van that the alarm has indeed set).
Problem is, the one wire I found I can use has a full 1 second pulse duration.
So, when I arm the system, the horn blows a bit long for this.
Ideally, I would like for the horn to just "tap" (a very short, quick blast of about 1/3 to 1/2 second blast as I arm the system.
Is there a way to decrease the duration from 1 second to 1/2 a second (or so) on a wire?
thx
Posted By: tommy...
Date Posted: October 01, 2009 at 2:12 PM
Are you sure there is no horn output...Just because it came with a siren does not mean there is not a horn output...Is there a link to the install manual...? Is the horn + or -...What is the polarity of the sirens output...? It is usually a positive trigger on the siren...If the horn is negative...Maybe you could use a relay and convert the polarity...Just guessing here...
-------------
M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: tommy...
Date Posted: October 01, 2009 at 2:37 PM
| Adding Light Flash with Siren Output | If your alarm has a positive siren output, but no light flash output, the connections are as shown. If you need more info on light flash start here.
 |
Maybe something like this...? ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: aviator172
Date Posted: October 01, 2009 at 2:39 PM
Hi Tommy,
No, after carefully reviewing each wire and it's purpose, there is no wire that is for attachment to the Factory horn to produce that short armed confirmation beep.
The manufacturer assumed that their siren would be used.
I used the Carvox's factory ARM wire for the horn and it does sound it but it has a longer than desired duration.
Instead of a quick and short little blip of the horn, I get a full 2.5 second blast.
A bit too long and annoying, especially late at night when I arm the alarm.
Posted By: tommy...
Date Posted: October 01, 2009 at 2:47 PM
Maybe follow that diagram...Of course it would be the horn instead of the light...I cant think of a unit that does not have a horn output...But anyway...Good Luck...! And is there a link to the manual...I believe what you said...I just have never seen/used this unit...And want to make myself a little bit more familiar with it...Thanks...! ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: aviator172
Date Posted: October 01, 2009 at 3:06 PM
There is no website listed in the manual I got with it.
If I can find a link I'll post it.
Thx
Posted By: howie ll
Date Posted: October 01, 2009 at 4:42 PM
Reads my post again, there's a note in the relay section on shortening pulses, if not Mr. Idiot can sketch you one or tommy, or me just stop whingeing and read what people post you.
Posted By: t&t tech
Date Posted: October 01, 2009 at 7:46 PM
Ummm! Just a thought! How about using the siren wire and inverting the signal to a negative that will trigger the horn, this way he would get the short blips of the horn when aring and disarming, If the unit has the option you can also program it to pulse when triggers, or else the horn would blare constantly when the alarm is triggered. If you don't like my idea, please read the signature. Cheers.
-------------
COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF.
PSALMS 37:5
Posted By: i am an idiot
Date Posted: October 01, 2009 at 8:01 PM
The following diagram is for a negative input and a negative output, do you need a negative or a positive output? https://www.the12volt.com/installbay/forum_posts.asp?tid=112480&KW=horn+honk+lock#542074
Posted By: tommy...
Date Posted: October 01, 2009 at 9:00 PM
t&t tech wrote:
Ummm! Just a thought! How about using the siren wire and inverting the signal to a negative that will trigger the horn, this way he would get the short blips of the horn when aring and disarming, If the unit has the option you can also program it to pulse when triggers, or else the horn would blare constantly when the alarm is triggered. If you don't like my idea, please read the signature. Cheers.
Relax T&T...Already covered that...Didnt you read the posts... ...Cheers... ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: t&t tech
Date Posted: October 01, 2009 at 9:11 PM
I did tommy! But i noticed you mentioned afterwards that you were just guessing. So i was just trying to ensure him that we know what we're saying! Cheers,  . ------------- COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF.
PSALMS 37:5
Posted By: howie ll
Date Posted: October 02, 2009 at 12:54 AM
Mr I and with a slight knuckle wrap from teacher's ruler to t&t and tommy, thank goodness someone reads my posts. I just wish aviator would.
Posted By: i am an idiot
Date Posted: October 02, 2009 at 5:38 AM
Has anybody seen Howie??
Posted By: t&t tech
Date Posted: October 02, 2009 at 6:16 AM
Nope! ------------- COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF.
PSALMS 37:5
Posted By: aviator172
Date Posted: October 02, 2009 at 8:20 AM
howie ll wrote:
Aviator, look to the relay section here for circuits, tommy, wish you better, aviator ref your last post, on certain Chryslers with resistive multiplex wiring, 200milliamps is not enough to overcome the resistance (s) you need e.g. on the locking system. If your unit only has two wires, it means a low current output signal is generated. If 6 wires, that means on-board relays and you're OK.
Howie,
I did read your post(s).
As I'm not quite the expert you are, this particular post appeared (to me anyway) to be about locking and unlocking and not specifically about the topic of this particular post (changing pulse duration).
So, if I missed the point and value of your post forgive me.
Sometimes what seems so obvious to an expert, is not quite as obvious to a lesser trained eye.
Thanks for everyone's help and patience 
Posted By: aviator172
Date Posted: October 02, 2009 at 8:31 AM
i am an idiot wrote:
The following diagram is for a negative input and a negative output, do you need a negative or a positive output?
https://www.the12volt.com/installbay/forum_posts.asp?tid=112480&KW=horn+honk+lock#542074
Perfect!
This link takes me directly to a way to do this.
Sorry if I missed it from other's posts.
I really appreciate all the help from everyone.
You guys really know this stuff inside and out 
I think a donation is in order 
Posted By: tommy...
Date Posted: October 02, 2009 at 8:33 AM
Do you need my paypal...Oh...you meant to the site...  Yeah was wondering if there was going to be a response to the several posts about using the sirens output to a relay...Or MR. I priceless info... Also you will get that cool symbol next to your name...! ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: aviator172
Date Posted: October 02, 2009 at 8:41 AM
tommy... wrote:
Do you need my paypal...Oh...you meant to the site... Yeah was wondering if there was going to be a response to the several posts about using the sirens output to a relay...Or MR. I priceless info...
Thanks Tommy,
You've been a big help.
I wiah I could compensate everyone for their time but funds are so limited these days!
I made a donation to the site but the info in the donation probably won't be identifiable to my account here on this forum. Should I pm the admin as to who the donation is from or is there no need?
thx
Posted By: aviator172
Date Posted: October 02, 2009 at 8:50 AM
Hi again,
As I was reading the thread containing the relay diagram to lengthen or shorten a pulse and saw this....
Chris Luongo wrote:
I'm pretty sure the only thing you can do with off-the-shelf parts like capacitors is extend the pulse, not reduce it.
A DEI 528T, or a PAC TR-7 pulse timer would probably do what you want, at additional cost.
So, now I'm wondering if this will do what I need or not?
thx
Posted By: howie ll
Date Posted: October 02, 2009 at 12:18 PM
I do have to work on occasional even at my age and it would be a bloody A3, still at least it was pre 04 so you've still got voltages where you want to go not data. Bloody trunk switch is pos! Aviator sorry if I confused you, I was trying to kill 2 birds with your relay question and this post. I've also used a 528t for speed instead of the resistor cap relay set up. It works out three times as expensive but it does the job.
Posted By: aviator172
Date Posted: October 02, 2009 at 1:50 PM
I spoke with a technician at PAC this morning and he advised that the TR-7 would NOT do what I wanted to do. I believe he said minimum pulse duration would be 1 sec with the TR-7. I believe his name was Ray?
Posted By: i am an idiot
Date Posted: October 02, 2009 at 2:17 PM
A half of a second is an eternity. Use the diagram I posted and maybe a 100 or a 47 microfarad capacitor.
Posted By: i am an idiot
Date Posted: October 02, 2009 at 7:01 PM
I did not make the diagram, I simply modified it to work with a negative input and to have a negative output. The diagram came from this site. It works, if it did not, you would not find it here. https://www.the12volt.com/relays/page5.asp#ctm
Posted By: OmarR
Date Posted: October 03, 2009 at 12:14 AM
aviator172 wrote:
Hi again,
As I was reading the thread containing the relay diagram to lengthen or shorten a pulse and saw this....
Chris Luongo wrote:
I'm pretty sure the only thing you can do with off-the-shelf parts like capacitors is extend the pulse, not reduce it.
A DEI 528T, or a PAC TR-7 pulse timer would probably do what you want, at additional cost.
So, now I'm wondering if this will do what I need or not?
thx
Yes, a 528t will work, cheap and easy. I use them all the time to adjust for the output that I need, be it a shorter pulse or a longer one, upto 90 seconds.
Posted By: howie ll
Date Posted: October 03, 2009 at 2:44 AM
Some thoughts here. Omar's right, Mr I is right, tommy and t&t are all correct. when it comes to general install knowledge, Chris Loungo is probably tops. Euro Cars, ask me, circuit designs, no one is better than Mr.I and if he says it wil work, believe him. If you have a relay question, himself or KP. 3 years ago I was in the middle of nowhere doing a 3 Series Cabriolet, arming the alarm with the roof down tends to lift the roof a couple of inches even set to 0.8secs pulse. Anal customer, I tried to set up the pulsed relay, no joy, no time or facility to bench test so I threw in a home made 528t (Velleman Kits). It worked perfectly. So go with whatever you think is right. In the UK that kit cost me £4.00, the 528t £7.00 and the relay set -up £2.00 (x 1.5 =$) Cost inthe labour on home made kit and relay set-up against the 528t.
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