Need help building project

[th41004]

Hi, I am trying to build a project and have little board building exp..What I want is a Sound device walkman,mp3,etc. hooked through a amplifiying device of somekind to a long range speaker,here is the hard part, I want to wire this up using a small 12 volt rechargable battery that I can turn Off and On from up to 150 meters. What I am having trouble with is the amplifier and remote, any suggestions?? I would like to keep cost around 100.00.+ Thanks.

 

[th41004]

bump

Any ideas??

 

[Nigel Goodwin]

I'm not really sure what you want?, what do you mean by 'long range speaker'?.

 

[th41004]

Just a horn type outdoor speaker.

 

[Nigel Goodwin]

Just a horn type outdoor speaker.

In that case I would suggest a car type amplifier, a simple bridged type will output 16W into a 4 ohm load. To remote switch it, you could either use a long wire!, or a low power licence free radio system - you can get them to work at that sort of range, particularly outdoors.

 

[th41004]

Where can I find a low power licence free radio system and how do they work. All I would need is something to disconnect 12v power at a distance. I want to leave the whole unit in the field and just have the remote on/off where I sit.

 

[audioguru]

1) A cheap horn outdoors speaker sounds awful when playing music or vocals. Have you heard one?
2) Horns are directional so you might need more than one.
3) How small is your "small 12V rechargeable battery"? It might not power a 16W amplifier long enough.

 

[tansis]

www.rfsolutions.co.uk has plenty of cheap and simple to use
transmitters and recievers that work in the 350-433mhz band.
Worth looking at the data sheet PDF's as many have circuits for remote controls included. Check out the discontinued items especially,
433mhz AM transmitter £3 , matching reciever under £10