Alternating horns

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

Could this wiring work!? 

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

Thanks,

Samo

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

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.

Thank again....

I found a better transistor interface.

http://www.overclockers.com/tips1122/index03.asp

I need to know, whether signal on 555 pin3 starts with positive value and after calculated time (R1,R2,C1) drops to negative.

or the other way

Here are some links that will help tou with the 555.

I think you can force it high or low with the reset mode on the timer.

http://www.uoguelph.ca/~antoon/gadgets/555/555.html

h ttp://home.cogeco.ca/~rpaisley4/LM555.html

http://www.eleinmec.com/article.asp?1

You could always go low tech