help rewiring a electric fan switch to a alarm clock?

[electronicnewbie123]

hello,
i don't know much about electronics so really need some help!
i want to connect a electric fan to a alarm clock in such a way that upon the alarm of the clock the fan will be switched on instead of the alarm speaker. i know to deactivate the alarms speaker i would just need to cut the wire to such but how would i then connect the fan in replacement?
thank you for any advice!

 

[Robert_fay]

First you would need a schematic of the alarm clock or take it apart and find out how much power you have going to the speaker. If it is enough you may be able to use this signal to trip a latching relay that will turn on an fan. If the signal is not strong enough you may have to look at a way to boost the signal or read it with a mico that will operate the fan.

 

[duke37]

If your fan needs mains voltage, I suggest that you delay implementation until you have more expertise.
A small low voltage DC fan should be safe to play with and can be switched with a transistor.

 

[electronicnewbie123]

If your fan needs mains voltage, I suggest that you delay implementation until you have more expertise.
A small low voltage DC fan should be safe to play with and can be switched with a transistor.

the fan is rechargeable so does not need to be connected to mains, thanks for help!

 

[electronicnewbie123]

First you would need a schematic of the alarm clock or take it apart and find out how much power you have going to the speaker. If it is enough you may be able to use this signal to trip a latching relay that will turn on an fan. If the signal is not strong enough you may have to look at a way to boost the signal or read it with a mico that will operate the fan.

thanks for help!

 

[Bluejets]

Microphone, few descrete bits and pieces and a relay and battery. No need to cut into anything.
Oh, and Google search for the circuit.
Try sound activated relay.

 

[swagguy8]

how long do you want the fan to run for? Forever? 10 minutes? If you want it to run forever, you could do the microphone circuit as bluejets mentioned, or if you don't want the sound, you could cut the speaker wires, and rewire onto a transistor circuit that controls the power to the fan. I would really suggest reading up on some transistor basics (https://www.electronics-tutorials.ws/transistor/tran_1.html), and get creative with it. What I would do is wire the speaker out to a capacitor, then use multiple transistor stages to turn on the fan, and then put a discharge resistor to control the time till it drops 0.7v. If I were you (noting what you said about not knowing much about electronics) I would use a microcontroller (arduino) to do it. Kind of overkill, but it will be the easiest way to achieve your goal.

good luck!

 

[electronicnewbie123]

First you would need a schematic of the alarm clock or take it apart and find out how much power you have going to the speaker. If it is enough you may be able to use this signal to trip a latching relay that will turn on an fan. If the signal is not strong enough you may have to look at a way to boost the signal or read it with a mico that will operate the fan.

Here is the alarm:

thanks for help!

Here is the alarm, can you interpret anything from this? Thanks:

 

[electronicnewbie123]

Microphone, few descrete bits and pieces and a relay and battery. No need to cut into anything.
Oh, and Google search for the circuit.
Try sound activated relay.

Thanks!

 

[electronicnewbie123]

First you would need a schematic of the alarm clock or take it apart and find out how much power you have going to the speaker. If it is enough you may be able to use this signal to trip a latching relay that will turn on an fan. If the signal is not strong enough you may have to look at a way to boost the signal or read it with a mico that will operate the fan.

Here are some photos of the alarm, can you interpret anything from this? Also I don’t want the alarm to make a sound anymore once the fan is connected. THANKS!

 

[electronicnewbie123]

how long do you want the fan to run for? Forever? 10 minutes? If you want it to run forever, you could do the microphone circuit as bluejets mentioned, or if you don't want the sound, you could cut the speaker wires, and rewire onto a transistor circuit that controls the power to the fan. I would really suggest reading up on some transistor basics (https://www.electronics-tutorials.ws/transistor/tran_1.html), and get creative with it. What I would do is wire the speaker out to a capacitor, then use multiple transistor stages to turn on the fan, and then put a discharge resistor to control the time till it drops 0.7v. If I were you (noting what you said about not knowing much about electronics) I would use a microcontroller (arduino) to do it. Kind of overkill, but it will be the easiest way to achieve your goal.

good luck!

Thanks for all that info, here is the alarm clock(below) so what do you mean by transistor stages?
THANKS AGAIN!!

 

[electronicnewbie123]

Hey guys Thanks for all advise. Swagguy8 if you could please reply to my reply when you get the chance, thanks again!

 

[RoseAleah22]

Hello!
That’s exactly what I want to do. Only slightly different. I want to connect a electric fan to an alarm clock in such a way that once the alarm goes off, instead of hearing sound, the fan will turn off.

 

[Harald Kapp]

@RoseAleah22 : do you realize that you replied to an old thread from 2018?
Have a look at mains timers to turn the fan on and off programmatically.