Hi All,

I have this goofy talking mistletoe thing that my kids love. It's motion activated so when you walk underneath it it says something with a French accent. Silly, and not really a great project, but again, my kids love it

Anyway, it has stopped talking when we walk underneath it. I took it apart and believe I have isolated the issue in the green sensor attached to the yellow and white wires. I can get it to talk when I jump the two contacts, so I have to think whatever the sensor is completes a circuit when you walk near it but otherwise keeps it open.

So, (assuming all of the above is correct, of course) can anyone tell me what the sensor is and what I would need to buy to replace it? Photocell? IR beam? Something else?

Thanks in advance!

 

The sensor is probably a small LDR (Light sensor).
Are the batteries and connections good?
Good luck....

 

Does light or dark affect it? Jigging the wires do anything? I, too, would guess that it's a photocell.

 

Yeah, it talks when you first turn it on, so batteries are not the issue. I can put a little piece of metal between the two terminals where it's soldered onto the circuit board and it talks so no other connections should be the issue. Pretty sure it's that sensor.

Ignoring what it is for the moment, how could I replicate its function? What would complete a circuit (by dropping resistance?) when it sensed motion, or light, or the lack of light? Would a CdS photocell reduce resistance if detected light? Or the absence of light? I'm obviously not well versed in this technology, so any advice is much appreciated.

 

Thanks for your reply.
They normally work by obscuring the light.
This is the sort of thing you require, if your light sensor is kaput.
In the UK we have a frog version, I had to replace the sensor in that.
20photoresistor LDR CDS 5mm light-dependent resistors sensors gl5516 arduin PM | eBay

Good luck....

 

Thanks for the suggestion! I ordered something similar, we'll see if it works.