As I'm thinking more on this topic, perhaps rather than one second on - or 1/10th of a second, in that 1 second you can flash it three times with an on time of 5 milli seconds on for a total of 15mS on time. But this would require use of a micro-processor. That way you can get really good timing. I'm totally unfamiliar with µP's so I have no idea how much current they would draw or how fast they would drain down a battery.

On the subject of batteries, I know you want to put this into a salt shaker lid - but if you go a different route you could have something for the salt shaker and other condiments on with a larger battery compartment. Maybe three AAA batteries that are easily replaced OR a rechargeable battery that every evening the unit can be plugged into a charger. OR even more so still, wireless charging.

Listen to me - - - I'm making your simple project into a large scale production. As always, you're the design engineer. You get to decide what you want and how you want it. I'm just offering a different thought.

 

As I'm thinking more on this topic, perhaps rather than one second on - or 1/10th of a second, in that 1 second you can flash it three times with an on time of 5 milli seconds on for a total of 15mS on time. But this would require use of a micro-processor. That way you can get really good timing. I'm totally unfamiliar with µP's so I have no idea how much current they would draw or how fast they would drain down a battery.

On the subject of batteries, I know you want to put this into a salt shaker lid - but if you go a different route you could have something for the salt shaker and other condiments on with a larger battery compartment. Maybe three AAA batteries that are easily replaced OR a rechargeable battery that every evening the unit can be plugged into a charger. OR even more so still, wireless charging.

Listen to me - - - I'm making your simple project into a large scale production. As always, you're the design engineer. You get to decide what you want and how you want it. I'm just offering a different thought.

Hi Tonyr1084,
The condiment tray is a great idea, but it won’t work for us. The shaker is essential, and we need it to stand out since it’s directly tied to our organization’s mission.
You might be right about turning the light on multiple times before a long pause, but for now, I’ll stick with the one-second on, 30-minute off approach.
Again, I really appreciate your advice and interest.

 

Is there product inside the shaker? If yes, that means people have to remove the cork to use the jar, and that just begs for someone to keep the cute little blinky thing. If no, there is a ton of room for a circuit and batteries.

Separate from that, there is a very common oscillator-divider circuit for long timer intervals that uses a CD4060. With a flash time of 1 second, a pause period of 17.067 minutes works out to a divisor of 1024. This fits perfectly into the chip's available outputs. Good news: no large timing capacitor. Bad news: 16 pin package.

And, as in #17, nothing will be smaller, cheaper, and more power-efficient than a 6-pin uC. Plus, you can have any flash pattern you can think of, such as a 5-flash burst every 20 minutes, for a zero change in component cost, size, and power.

1 - chip - 6-pin SMT or 8-pin DIP
1 - decoupling cap
1 - resistor
1 - LED

ak

 

To add to my original post, I run a charity, and we’ve launched a campaign where all local restaurants and cafés have a "shaker" (see image) with a QR code in the back. Scanning it takes you to our website, where people can learn about our work and, ideally, make a donation.

So test out the simple 2032 batt and a self blinking LED. I think you could add a small cap and high ohm resistor to make cap do slow charge up and at some threshold the self blinking LED should flash and drain the cap down, maybe something like 10uF and 200k resistor. There will be some obvious leakage, but I think a fresh 2032 could last quite a long time. I will try and make it in LTspice.

Something like 20M resistor and 10u cap (or 200M and 1u). The cap should charge slowly and when it can get high enough to reach threshold of blinker LED, the LED should conduct and the cap provides the jolt and drains out and LED shuts off, rinse and repeat, etc.

How long a fresh 2032 might last is something to test.

 

CMOS 555 Long Duration Minimum Parts LED Flasher