Opening and closing a simple, inaccessible circuit with an impact such as a tap or slap

Thread Starter

FlowJuggler

Joined Jun 3, 2022
5
I am trying to turn on and off an LED that is contained within a small sack of sand. I am seeking a switch or sensor that will help me accomplish this goal.

Thank you for your time and consideration.
 

LowQCab

Joined Nov 6, 2012
2,171
Check out the huge selection of Sensors for Car-Alarms.
Glass-Breakage, Short-Range-Field-Disturbance ( sometimes called "Radar"), Vibration, Tilt, etc., etc..
They're cheap and easy to work with.
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Tonyr1084

Joined Sep 24, 2015
6,883
I'm for the shaker switch - a spring inside a tube. When the tube is shaken the spring touches the side and triggers a circuit. But with your desire to do this once and have it on and one more time to have it off - a shaker switch isn't the best option. UNLESS you seal the shaker inside a non-conductive oil to dampen the movement. Then a single whack on the side will trigger it. Then another whack and it can toggle it back off. I'd think a Double D type Flip Flop (DDFF) with the /Q tied to the D (Not-Q & Data). Every time you clock the DDFF you will change states.

Now, for the LED - depends on how much current the DDFF can handle and how much current you want to drive your LED with.

THEN there's the issue of power. Battery? Inside a sealed container? Rechargeable? How will you recharge it? If not - how will you replace the battery? A hatch with a screw cover? Just a few things I can think of that need to be considered in your project.
 

Tonyr1084

Joined Sep 24, 2015
6,883
An additional comment on the shaker switch - - - my cats have a bunch of toys that make some sort of noise whenever they play with them. Batteries have gone dead in a few and I've taken them apart to replace the battery. They're just a simple tube with a light weight spring inside. The one end is sealed with an epoxy and the other end is just open. When the toy is played with it triggers a circuit with a pre-recorded sound to stimulate the cats. Something similar - with just a single closure to trigger a timed program. It lasts about a second, so the spring is not making contact for long, just for the moment. That's probably enough, but to insure with the DDFF you're not triggering and retriggering it over and over in a single whacking event.
 

MrSalts

Joined Apr 2, 2020
1,832
If it is low power, you can look at kids super balls with LEDs in them. They usually just have a lightweight spring soldered to the PCB and a pin coming up from the center of the spring. Any bounce, causes the spring to touch the pin. That connection starts a low current timer like a CD4538 or similar monostable multivibrator or microcontroller. The LEDs stay on (flash) for a specific period and then sleeps again.

again, they are kids super balls from the dollar store so this is about as inexpensive as it gets.
 

Thread Starter

FlowJuggler

Joined Jun 3, 2022
5
But with your desire to do this once and have it on and one more time to have it off - a shaker switch isn't the best option. UNLESS you seal the shaker inside a non-conductive oil to dampen the movement.
I do not require that the LED turn on and off. Rather that the switch triggers an NE555 to keep the LED on for a duration. Thanks for prompting me to be more clear in explaining my needs for this project.

And an interesting idea to dampen a spring switch with oil. Thanks.
 
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