Bite alarm to switch on led lights

[birdie]

Hi, I'm a carp fisherman and what I want is, when my bite alarm buzzes in the night I want it to bring my led lights on automatically,
My lights run from a 12v battery, I know I need some sort of sound sensor, I would like the lights to stay on for a couple of minutes then go off, is there any chance you could do a circuit for me
Cheers
Paul

[KMoffett]

Can you post a link to your bite alarm? How much experience do you have building electronic devices?

Ken

[birdie]

Hi, the alarms are fox mmxr, I have built a few circuits, the last one was the automatic chicken door opener which was put on here by pebe, I can read most drawings
Cheers
Paul

[KMoffett]

Maybe something like this plus a voltage regulator (LM7805...12V>5V), a couple of capacitors (for the regulator) and a small relay. [url]http://www.ebay.com/itm/Microphone-Sensor-High-Sensitivity-Sound-Detector-Voice-Switch-Arduino-Module-/272161285623?hash=item3f5e13a5f7:g:ByAAAOSwv9hW3woK[/url]
Relay contacts would parallel the LED light switch. How much current do the LED lights draw?

Oops! Forgot the delay. OK, a monostable between the PCB and the relay. Could be a 555 or a MOSFET monostable.

Ken

[birdie]

Hi Ken, just looked it up, there are 60 LEDs in a strip, it says it's 4.8w/meter and 0.4A/meter and I'm only using 30 of the LEDs,
Can you draw me something up so I can have a go at building it
Cheers
Paul

[KMoffett]

Perhaps if you're not in a hurry. How many meters for 30 LEDs?

Ken

[birdie]

Hi, I'm in no hurry, i am going to use 30 leds which is half the length which is half a meter, i can use less if that makes it better for lower current
cheers
Paul

oh,is it possible to be able to vary the delay so i can have it on longer or shorter sometimes?

[KMoffett]

OK, here's a shot. A 78L05 regulator to drop the 12V supply down to 5V for the sound module. A 555 monostable triggered by a logic high from the sound module. The 555 monostable output time can be varied from 24 to 240 seconds. The 555's output drives a small relay. the COM and NC contacts on the relay are wired in parallel with the contacts on the switch that normally control the LEDs.

Ken
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555 fish Monostable.gif (26.31 KiB) Viewed 62718 times

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[birdie]

Thanks Ken, looks brill, I'll order the parts and see if I can put it together, I'll let you know how I get on
Cheers
Paul

[PradeepKumar]

i think the circuit will work on but ensure that the bite alarm units you are attempting to match to your receiver are switched on.