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djkross
djkross • Dec 23, 2007

555 Astable Siren

hey, guys. i've just built a siren for a project i'm doing and i'm kinda stuck.basically what i've done is use 1 monostable 555 to control the output of the 2 astable 555's by using a switch button. to turn it on and off (with variable longevity of siren noise). where i'm stumped at is... if i'm going to control this thing using a PIC, i have to replace the switch button because we're going to send a signal to the siren in order to fire it. so...

1) How exactly do I do that? It's been a while since I last messed with micropressors!! I honestly have no idea for this one... I need something that'll act as a switch... I know that much...

2) If I want to amplify the output to say... 50-60dB, how would I do that? Anybody know of a amplifier chip + schematic that could help me achieve that?

Thanks in advance! I hope you guys have loads of ideas! 😁
djkross
djkross • Feb 15, 2008
no replies?
reachrkata
reachrkata • Feb 24, 2008
From what I have understood of your short explanation -

1) You can use a transistor as a switch and use a controller port to drive the transistor.

2) Transistor amplifier again !!

I suggest that you share your schematics so that we all can get a better idea.

Karthik
Hi...you can use a simple relay and connect them to your switch or replave it with a relay,as for amplifier you can definately go for op-amp,i can help u with the schematics,but were shud i e-mail u.....and giveme a weeks time for that!!!

djkross
hey, guys. i've just built a siren for a project i'm doing and i'm kinda stuck.basically what i've done is use 1 monostable 555 to control the output of the 2 astable 555's by using a switch button. to turn it on and off (with variable longevity of siren noise). where i'm stumped at is... if i'm going to control this thing using a PIC, i have to replace the switch button because we're going to send a signal to the siren in order to fire it. so...

1) How exactly do I do that? It's been a while since I last messed with micropressors!! I honestly have no idea for this one... I need something that'll act as a switch... I know that much...

2) If I want to amplify the output to say... 50-60dB, how would I do that? Anybody know of a amplifier chip + schematic that could help me achieve that?

Thanks in advance! I hope you guys have loads of ideas! 😁
djkross
djkross • Feb 26, 2008
is there a siren/speaker i can use with an amplifier already installed in it?
Dude,there are lot of ways u can control your 555,which is suitable for your application can be determinrd only after seeing ur ckt diagram,u may have to make changes in your code too


djkross
hey, guys. i've just built a siren for a project i'm doing and i'm kinda stuck.basically what i've done is use 1 monostable 555 to control the output of the 2 astable 555's by using a switch button. to turn it on and off (with variable longevity of siren noise). where i'm stumped at is... if i'm going to control this thing using a PIC, i have to replace the switch button because we're going to send a signal to the siren in order to fire it. so...

1) How exactly do I do that? It's been a while since I last messed with micropressors!! I honestly have no idea for this one... I need something that'll act as a switch... I know that much...

2) If I want to amplify the output to say... 50-60dB, how would I do that? Anybody know of a amplifier chip + schematic that could help me achieve that?

Thanks in advance! I hope you guys have loads of ideas! 😁
djkross
djkross • Feb 27, 2008
[​IMG]

diode 5 is an LED.
R8 is the speaker.
R11 is wired to RB7 of the PIC.

we have the code working to trigger the siren. all i need now is a speaker with an amplifier built in it 😔
hey buddy,hope ur doing well,as for ur prob.Do one thing use ULN 2003 IC which is CMOS to TTL converter,use the output of ULN 2003 to triggre the base or Transistor,which can be used as a switch for your 555,do ask me if u have any issues...good bye

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