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. http://www.ebay.com/itm/Microphone-Sensor-High-Sensitivity-Sound-Detector-Voice-Switch-Arduino-Module-/272161285623?hash=item3f5e13a5f7:g:ByAAAOSwv9hW3woK
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

555 fish Monostable.gif (26.31 KiB) Viewed 53486 times

[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.