Need a little help choosing electronic components for this project

Thread Starter

OldCodyJr

Joined Sep 21, 2018
6
I'm building a battery powered device that buzzes for 30 seconds when it's shaken. I don't have much experience with electronics, so I don't know what components to use.

Here are the requirements:
  • Must buzz for 30 seconds when shaken.
  • Must be powered by a battery.
  • Must fit in a 5/8" diameter x 1-3/4" long tube
So, what kind of timer and sensor would you recommend?

Any help would be greatly appreciated! :)
 
Last edited:

oz93666

Joined Sep 7, 2010
737
First thing you need is a tilt switch ...ten for $1 inc delivery!! on eBay

Inside is a small metal ball .When turned upside down ,or shaken it makes momentary contact with the two wires completing the circuit ....

Then you need some electronics .
 

KJ6EAD

Joined Apr 30, 2011
1,570
When you say buzzer, do you mean audio only or vibration also?

With the "ball in cage" tilt switches, use two or three in varied orientations to avoid a failure to trigger with certain linear movements.

Vigorous shaking can momentarily overcome the spring tension of some battery holders causing a circuit interruption. Keep this in mind for your design.
 

Thread Starter

OldCodyJr

Joined Sep 21, 2018
6
When you say buzzer, do you mean audio only or vibration also?

With the "ball in cage" tilt switches, use two or three in varied orientations to avoid a failure to trigger with certain linear movements.

Vigorous shaking can momentarily overcome the spring tension of some battery holders causing a circuit interruption. Keep this in mind for your design.
Audio only.
 

AnalogKid

Joined Aug 1, 2013
8,314
The problem with a tilt switch is that the device might be left resting with the switch closed. This will be a small, continuous power drain on the battery after the buzzer has timed out. Better would be a spring-loaded mechanism such as what is in a shock sensor. A short piece of #24 solid wire with a small blob of solder on the end for a weight works well.

Also, I recommend against a 555 for this. Even the CMOS version has an idle current of 50 uA at 1.5 V. A CD4093 plus a 2N7000 as a buzzer driver will do the job with way less idle current.

If you don't mind the buzzer tapering off gradually rather than shutting off crisply, you can eliminate the 4093 and possibly the 2N7000. Battery + switch + big capacitor across the buzzer, no active devices.

ak
 

Bernard

Joined Aug 7, 2008
5,399
Where are you located? Some possible parts.
Beeper, 2.3 kHz, 4-7V, 12 mm dia. X 10mm, US $ .85, All Electronics.
Battery, CR1025, LI., 3V, 30 mAh., 10mm X 2.5 mm, 2 ea.
Timer, C555, CAT # ICM7555, $ 1.00, All Electronics.
Possibly a power switch for long idle times?
 

Bernard

Joined Aug 7, 2008
5,399
With @AnalogKid's concern for C555 current draw long term I dug into the past & found from " Electronics"
May 26, 1969, Designer's casebook, " One-shot multivibrator requires no standby power"
AS Electronics is defunct might it be OK to print page.
 

Bernard

Joined Aug 7, 2008
5,399
My first thought on container was Lip Balm tube, 14.7 mm ID x 50 mm ID
Looks like all parts might fit, inc. 1200 mAh battery; ICM7555; beeper, 9mm x 5mm; tilt SW, 5mm.
Will wate for dimensions update.
.
 

Colin55

Joined Aug 27, 2015
519
LONG DELAY TIMER A new chip on the market produces times up to 1,000 hours. It is called C005. Here is the prototype where we tested the chip:




Back of the timer module showing the two wires for the pot.





A kit is available for $8.00 and comes with all components and a printed circuit board with all parts clearly shown on the overlay.
The pot is marked with 1 to 10 hours and this will be ideal for most applications. The tactile button starts the timing and the buzzer sounds when the time is up. Two output pins are also provided on the PC board to connect to other devices to turn them ON.
The output of the board turns ON a device such as a relay, after say 5 hours, and the contacts on the relay will turn the device OFF. The buzzer on the board will let you know the 5 hours is up.

The project is connected to 3 x AA cells (4.5v) (in a battery box)
Consumption when timing: 100uA
Output: pull-up 3mA pull-down 30mA
 

BR-549

Joined Sep 22, 2013
4,938
Ok...I found that when I searched......but no new chip. That part number was an rf chip. No problem.....just different terminology. I wouldn't call a module....a new chip. And it does not bother me that you do. It was just that I couldn't find a new chip. I like new chips.
 
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