Can you measure the DC and AC voltage coming from the speaker wires? Does this go to zero when the alarm is off?
Is this alarm a tone or from a radio?
If you can use a separate battery then you can likely use a transistor amp to turn on the motor.

crutschow

when alarm is off, there is not voltage (0 dc voltage) across speaker wires.
when alarm is on, it start beep, then another type of beep, and then last type (loudest) type of beep.
when alarm starts, the voltage starts increasing and continuously fluctuating.
the voltage is different when speaker is connected, and when speaker is not conected.
when alarm is on and mulimeter in connected to terminals then if i put fingers on the terminals of multimeter, the voltage rises to around 0.75 , i don't know why

 

Can you measure the DC and AC voltage coming from the speaker wires? Does this go to zero when the alarm is off?
Is this alarm a tone or from a radio?
If you can use a separate battery then you can likely use a transistor amp to turn on the motor.

do you want the video of the voltage from multimeter?

 

do you want the video of the voltage from multimeter?

Not necessarily. Can you read the peak voltage value of the fluctuating voltage with and without the speaker?

 

Use a full wave bridge rectifier then a 1000 ohm resistor then a smoothing capacitor (say 47uf?) onto the base of an NPN transistor (bc337 maybe?) put the motor between the collector and new power supply and emitter to ground . Ground the negative speaker wire too

 

Use a full wave bridge rectifier then a 1000 ohm resistor then a smoothing capacitor (say 47uf?) onto the base of an NPN transistor (bc337 maybe?) put the motor between the collector and new power supply and emitter to ground . Ground the negative speaker wire too

No. You don't what to ground the speaker wire from the clock if it is also going to the bridge. That will short out the bridge.

 

Oh yes... Must try harder.. I meant Ground the negative from the bridge

 

Oh yes... Must try harder.. I meant Ground the negative from the bridge

Rich2

please make a circuit diagram and attach image. make on paint atleast

 

Err... can anybody do a diagram? I can only type things on this, an iPodtouch

Sorry :-(

 

Something like this perhaps...........

 

Yes something like that, thanks

 

is it necessary to use bc337. i have another transister, bc546 perhaps, don't remember exactly

 

Hello,

It depends on the current used by the motor.
A BC337 can have more current than the BC546.

Have a look at the table I posted in this post to select you transistor:
http://forum.allaboutcircuits.com/threads/components-selection-guide.65137/page-2#post-669230

Bertus

 

On Rich's circuit, it would be much better to use a voltage doubler than a bridge. Place the resistor between the filter cap and the transistor base. A capacitor on the base never develops much voltage and it is drained away almost immediately.