Aftermarket backup sensor - so LOUD!

[cpgoose]

Hi folks,

So I bought this backup sensor from Amazon and installed it on my car.

here's the link

The problem is that it's so LOUD! Instead of wiring it to the backup lights, I just installed it to an on/off switch so I can use it when I want. If you look at the pictures, the last picture is of the LED display. That is where the little speaker resides that beeps. I opened it up to see what it looks like, and the little speaker is soldered to the circuit board.

Any ideas on how to control the volume of the speaker? Potentiometer? Rheostat? Please don't say to just put a piece of tape over it I actually did that, and it's still loud. I was curious if I could unsolder the speaker and hookup a potentiometer between the circuit board and the speaker to control the volume?

Any ideas would be great?

 

[davenn]

Yeah a layer of tape on the outside looks a bit rough

Seriously !!
before going the electronic mod way .... open the box up and try just dampening the speaker with layers of foam, paper, cloth whatever. I have been able to more than halve the volume level of beepers that way


electronic way ... try replacing the speaker with a single earphone from an old set of the "bud" mp3 player/phone earphones


Dave

 

[BobK]

Dave,

It is a backup sensor intended to warn the driver when he is about to hit something, not the beeper intended to warn the person he is about to hit.

Bob

 

[davenn]

yes I know .... you missed my edit

 

[cpgoose]

Thanks for the replies folks. I'll give the foam/tape method another shot, but the idea of being able to control the volume seems appealing if it's easy enough. It would also allow us to use the backup sensor with the visual alerts and have the sound off (and not wake up the kiddies).

If I unsolder (desolder?) the speaker from the board, how do I solder wire to the board so I can hookup something else, like an L-pad?

 

[BobK]

yes I know .... you missed my edit

Yep, I am not a time traveler.

I thought the same on first reading.

Bob

 

[cpgoose]

I scanned the board so you could see. The 2nd and 3rd images are the same, I just labeled the 3rd one.

You can see the tiny speaker in the first image. In the 3rd image I labeled what I think are the two terminals for the speaker. What's strange (to me at least) is that it looks like the board's inner wiring only goes to one of the speaker terminals and not both.

 

[(*steve*)]

Simple solutions:

• Tape over the beeper
• Cotton wool around the sensor
• Seal up any holes in the enclosure
• Isolate enclosure from resonant surfaces
• Combinations of the above

If none of these work, then you could try placing a resistor in series with the beeper. I can't recommend a value -- this would have to be determined by trial and error.

Both sides of the transducer are connected. It's just that the wire for the apparently isolated one is on the other side of the board.

If you're not careful, removing the transducer might result in damage to the transducer, the board, or other components.

 

[cpgoose]

One last follow-up question: The wires for each of the 4 sensors are a little too short. I cut the connector off one of them and there are two wires inside with silver shielding. Any tips on how to extend these wires without losing the shielding capability? I've never extended shielded wire before.

 

[(*steve*)]

If you get similar shielded cable you can connect the like conductors together Use heatshrink (not tape) to insulate the inner conductor and larger heatshrink (not tape) to insulate and seal the outer braid.

If you can push the braid back so that it can be pulled back up to almost cover the join, that's great. However as long as the gap is small you should be OK. If it picks up interference, you can get copper tape from gardening stores (it's used to protect plants from snails) and wrap the break in the braid with this. It may not make an excellent electrical connection (but you've already connected the two braids) but it should suitably cover the gap. If you think you might need to do this, leave another piece of unshrunk heatshrink near the join so you can slip it over the repairs -- otherwise you'll have to undo something to get more over the cable.

 

[cpgoose]

Awesome, thanks for the reply - I'll give it a shot. Is plain 'ol house foil the same idea as the foil shielding in my wire? (It's not the braided kind, it's the foil kind.)

 

[(*steve*)]

Foil shielding usually has a wire running with it. You can't solder to the foil, but obviously you can solder to the wire. It's also often easier to peel back.