Alternating horns

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=76824
Printed Date: July 12, 2025 at 8:02 PM

Topic: Alternating horns

Posted By: rajkovic
Subject: Alternating horns
Date Posted: April 26, 2006 at 10:59 AM

Hello!

I'm making old euro-type siren (HI-LO) from auto-horns. They have two different frequencys. I want to hook up one relay for each horn on controller.

1. I need wiring diagram for controller.. any suggestion?

2. Can I hook up just one alternating relay on NE555 oscillator?

3. I need to know how strong is the trigger current on standard auto relay. Is it 200 mA?

Thanks, Samo

Replies:

Posted By: rajkovic
Date Posted: April 26, 2006 at 11:19 AM

Posted By: rajkovic
Date Posted: April 26, 2006 at 2:49 PM

Could this wiring work!?

Just need a quick check of the diagram, which I draw. posted_image

Thanks,

Samo

Posted By: hotwaterwizard
Date Posted: April 26, 2006 at 11:17 PM

A simple relay controller with transistors would work as well. posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: April 27, 2006 at 12:08 AM

You could use a regular Automotive Relay if you add a transistor to the output of the 555.

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: rajkovic
Date Posted: April 27, 2006 at 3:30 PM

I appreciate your help. I need to run my horns on 12V dc, so I dont think the first one will work. Well then, I' ll use my configuration of two relays and connect the 2. hotwaterwizards configuration on second relay.

I thought that NE555 chip is capable of running 500mA on exit. posted_image

posted_image