Car Reverse Beeper

[iONic]

Bought a "Car Reverse Beeper", assembled it, and tested it in the house to great satisfaction. After installing in the car (Not running but with it in reverse and with emergency brake on) it also worked good!

The when I started the car and backed out of the garage the beeping frequency became very eratic as I tapped the brake or turned the steering wheel. Apparently the small output voltage to the Pizzo changes.

Any suggestions on how to stableize this??

**broken link removed**

 

[iONic]

Reverse Beeper

Maybe this can be done with an IC and a 317 Roltage regulator??

Any schetches/schematics would be most helpfull!

B

 

[stevez]

I don't know how sensitive piezo buzzers are to applied voltage - especially the one you have. I'd experiment by applying different voltages to the buzzer to see what happens - if for no other reason than to rule out or rule in the voltage variation that you suspect as a cause. You might also establish whether or not you'll be satisfied with the performance of the buzzer at other voltages.

I'd also have someone observe the backup lights. I'd guess this is where your circuit tells your alarm that you are in reverse. If the backup lights are flickering you might want to repair that first then move on.

I don't know what your circuit does - maybe it's a voltage regulator already - I'm not sufficiently skilled to recognize the circuit. It would seem that an LM317 would do the job directly off the backup light circuit but that's just a shot in the dark, so to speak.

 

[Nigel Goodwin]

I don't know what your circuit does

It's simply two astable multivibrators, with a slow one gating a fast one, so you get the 'beep, beep, beep' noise. There isn't any need to have a regulator feeding it, if there's a problem it's either a constructional fault, or a problem with the car electrics.

 

[Roff]

It could be ignition and/or alternator noise. You might try adding 100 ohms in series with the +12V line, with a BF cap (at least 100uF) to GND from the junction of the 100 ohms and the beeper.

 

[suicidalmonkey]

Why don't you learn how to drive!

I have never used a reversing sensor and have never had a problem reversing.

It's when people rely on this technology, and one day, for what ever reason, it fails that they hit someone/something.

 

[Nigel Goodwin]

Why don't you learn how to drive!

I have never used a reversing sensor and have never had a problem reversing.

It's when people rely on this technology, and one day, for what ever reason, it fails that they hit someone/something.

Perhaps you should try reading the thread?.

It's NOT a reversing sensor, just a reversing beeper, to warn people there's a vehicle reversing.

 

[stevez]

Alarms such as these are required here in US on industrial vehicles, construction vehicles, etc. Some companies require personal vehicles to be fitted with reversing alarms when driven on company property. Visitors must sound the horn before backing the vehicle.

 

[suicidalmonkey]

Perhaps you should try reading the thread?.

Now the schematic makes more sense. For some reason my first impression was a reversing sensor, and that thought stayed in my head the whole time.

I'm sorry about the way I reacted. I think we have a similar law in Australia, although I think flashing light or some sort of warning on the back of a vehicle would be more suitable. Personally, I don't react when I hear a reversing beeper because it could be coming from any vehicle near me, revering in any direction (not necessarily towards me).

 

[iONic]

stevez wrote:

You might also establish whether or not you'll be satisfied with the performance of the buzzer at other voltages.

I will do that as pressing the brake lights causes changes and when I turn the steering wheel it also changes tones.

Ron H wrote:

It could be ignition and/or alternator noise. You might try adding 100 ohms in series with the +12V line, with a BF cap (at least 100uF) to GND from the junction of the 100 ohms and the beeper.

I will do this gust as soon as I determine if the pizzo freq. changes with varying voltages.

suicidalmonkey wrote:

Why don't you learn how to drive!

I have never used a reversing sensor and have never had a problem reversing.

It's when people rely on this technology, and one day, for what ever reason, it fails that they hit someone/something.

I for one will admit, as I am sure others here here will too, that there are times when the BRAIN skips a beat. There have been cases in which I have driven right through an intersection through a stop sigh or even a red light only to realize after of my wrong doing. Of course I will, with all intentions, look behind me when I am reversing but this device just makes it a bit safer for those pedestrians that may be near when one of those
BRAIN SKIPS.


[/quote]

 

[Roff]

Personally, I don't react when I hear a reversing beeper because it could be coming from any vehicle near me, revering in any direction (not necessarily towards me).

Well, that makes a lot of sense. If you hear an alarm, it might possibly be a false alarm, so just ignore it. If it's a real alarm, well, what the hell, you only die once. :roll: