Trying to make the beep longer on Viper 800esp?

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=9507
Printed Date: August 18, 2025 at 9:36 PM

Topic: Trying to make the beep longer on Viper 800esp?

Posted By: maximaonbags
Subject: Trying to make the beep longer on Viper 800esp?
Date Posted: February 14, 2003 at 11:42 AM

The only idea that I have had thrown at me is to wire up a "capacitor or 2" in the siren's wiring, but I really don't know how much that would actually do to make it work.

I am trying to make the actual "beep" longer when I arm and disarm the alarm... basically to have it go from "beep beep" to "beeeep beeeep" (on unlock of course).

This may be very simple, but I really have no idea where to even start?

Reasoning behind this is because I have a showme siren as my alarm siren and it needs a longer signal to have it make noise on short beeps.

Thank you in advance.

Jason Sadler

Replies:

Posted By: maximaonbags
Date Posted: February 16, 2003 at 10:30 AM

No ideas?

Posted By: maximaonbags
Date Posted: February 18, 2003 at 10:05 PM

Still looking for some help..

Posted By: RocketRanger
Date Posted: February 18, 2003 at 10:16 PM

Your cap idea could work.

I'm thinking a relay cap combo. Have the siren out of the alarm drive a relay instead of the siren itself. Place a cap in parallel with the coil side of the relay.

Finding the discharge time of a cap\coil combo is very easy.

T=RxC You need C=T/R

T=Discharge Time to 63% of Supply (12V)
R=Load Resistance (Standard Bosch Relay is 80-100ohms)
C=Capacitor value in fareds

Example:

I want my relay coil active for approx .25seconds (T=.25)
I have a bosch 100ohm coil relay (R=100)

I need a capacitor size of 2500uF (.25/100=.002500)
(Remember electrolytics have polarity. No backwards!!!!)

This value would be a starting point. You'd have to experiment with cap values until you find an acceptible value. WHY? Relays latch up hard at 12V, but can hold to as little as 2V. Depends on size of relay.

I'd start with a value of around 470uF. You can also start with a large cap (2500uF maybe?) and put resistance in parallel with it to drop discharge time to what you need (Use 200 Ohm 1Watt resistors) Don't exceed the current capacity of your alarm siren output.

Recommend starting with a 470uF. Add another in parallel if not enough time. Test unhooked from alarm siren out. Manually simulate the 12V siren output by taping a wire on the cap\coil combo positive connection. Easier to figure acceptible time..

Hope this helps....

Rocket

You must experiment.

Posted By: EVSolutions
Date Posted: February 18, 2003 at 11:26 PM

Rocket,

Is it possible to use the relay as a delay on timer say, 6 to 8 seconds with caps?

Sean

Posted By: RocketRanger
Date Posted: February 19, 2003 at 1:07 PM

Would take more then just a relay\resistor\caps.

Other options:

555 Timer IC
-MANY books on this. Radio Shack has a $3 book
-Cap\Resistor\Transistor\Relay combo would work

Recommend 555 timer reading.

Interested in any ideas from others who know a simpler way to do the above mentioned timed-on relay. I know there are commercial timer relays, but they are way to expensive.

Rocket