How to make the led to flash once every minute?
Please reply with circuit.
Thanks.
**
i want to make battery indicator with 3mm green led blink once (1sec) every minute. It is similar to smoke alarm led indicator that blinks once every minute.
Will use 9v and 12v battery.

 

How to make the led to flash once every minute?
Please reply with circuit.
Thanks.

How long is the LED on vs off (on one minute, off one minute), (on one second and off for 59 seconds)?

How many milliamperes is the LED?

What kind of power supply (wall adapter, battery, ...)

 

How much are you wiling to pay for engineering services ? ? ? Or would you rather develop an idea on your own and ask for guidance? Guidance is much cheaper. I already know how I'd accomplish it. It's not difficult. But I at least have an idea. What's yours?

[edit] I see Gopher is on the thread. He's got a good question regarding duration and such. I'm wondering how accurately you want the timing of this thing? Do you mean "About a minute" or "A minute exactly"? And if exactly, then HOW exact? There's no such thing as absolute accuracy, so what's your tolerance?

Do you have an Arduino (or other micro controller)? Can you write code? Do you prefer a hardware approach? (chips and caps and such)

[edit] Ultimately, what's your goal? Your purpose?

 

How long is the LED on vs off (on one minute, off one minute), (on one second and off for 59 seconds)?

I think were Gopher is going here (other than asking for more details) is that a flash an interval every minute will likely go unnoticed. Who would be looking at an LED for a full minute?

 

You need to provide details. Not just requote what gopher wrote.

 

You need to provide details. Not just requote what gopher wrote.

I am making battery indicator and i want the led indicator to blink once (1sec) every minute
I will use 12v battery and 9v battery

 

Again, for what purpose? Spinnaker has a good point when he said "Who's going to watch an LED for a whole minute?" If I were watching for an LED indication after one minute, chances are it would flash just at the moment I blinked. I'd rather some sort of count down, like starts blinking within 10 seconds of that minute and then when the full minute is up it flashes a different LED.

What it sounds like you're making is just a simple battery powered LED. What will a blink every minute tell you? It won't tell you the state of charge or how much energy has been used or remains available. I would really like to know more about what you are targeting (hoping to accomplish) with this project. Otherwise all you have is a blinking LED that blinks once every minute.

Little advice regarding charging and discharging circuits: They depend on a stable voltage. If you power from a battery then as the battery loses its power the blink rate would slow down. Meaning it may start blinking every 70 or 80 or even 90 seconds. If you're going to sit there with a stop watch and time the blink rate - well, if that's all you have to do for that minute (or so) then I guess that's your business. But if you decide to plug it into a 9 volt battery then you can expect (with the 12 volt battery as a starting point) the 9 volt battery on the same exact circuit will flash once for every 75 seconds (estimated).

Details. We need to know what you want. If it's simple enough then someone will be glad to help you reach your goal.

 

Again, for what purpose? Spinnaker has a good point when he said "Who's going to watch an LED for a whole minute?" If I were watching for an LED indication after one minute, chances are it would flash just at the moment I blinked. I'd rather some sort of count down, like starts blinking within 10 seconds of that minute and then when the full minute is up it flashes a different LED.

What it sounds like you're making is just a simple battery powered LED. What will a blink every minute tell you? It won't tell you the state of charge or how much energy has been used or remains available. I would really like to know more about what you are targeting (hoping to accomplish) with this project. Otherwise all you have is a blinking LED that blinks once every minute.

Little advice regarding charging and discharging circuits: They depend on a stable voltage. If you power from a battery then as the battery loses its power the blink rate would slow down. Meaning it may start blinking every 70 or 80 or even 90 seconds. If you're going to sit there with a stop watch and time the blink rate - well, if that's all you have to do for that minute (or so) then I guess that's your business. But if you decide to plug it into a 9 volt battery then you can expect (with the 12 volt battery as a starting point) the 9 volt battery on the same exact circuit will flash once for every 75 seconds (estimated).

Details. We need to know what you want. If it's simple enough then someone will be glad to help you reach your goal.

As I mentioned several times above, i want to make battery indicator with 3mm green led blink once (1sec) every minute. It is similar to smoke alarm led indicator that blinks once every minute.
Will use 9v and 12v battery.

 

As I mentioned several times above, i want to make battery indicator with 3mm green led blink once (1sec) every minute. It is similar to smoke alarm led indicator that blinks once every minute.
Will use 9v and 12v battery.

I don't mean to keep beating this horse, but what you're telling us (me anyway) is you just want to make a flashing LED. IF you want it to tell you something (other than it is on every minute) then what is it you hope to know from this flashing LED? is it just that you're running on battery power? If so then you don't need to flash an LED for 1 second every minute. You can flash it for 1/6th of a second every 10 seconds. Or 1/60th every second. Or anywhere in-between for any duration. If power consumption is your concern then understand that most super bright LEDs will give plenty of light indication at very short duration pulses AND at running on 5 mA of current. You can go even lower if all you want is a light to indicate you're running on battery power.

I can spend thousands of your dollars building a circuit to do what you want - OR you can get away with just spending pennies if all you want is an indicator that periodically blinks. You mention a smoke detector. go watch your detector and try to measure the period of time the LED is actually lit. It's far less than a whole second. In terms of electronics - a second is a rather long period of time for an indicator light to be lit.

So I'll ask again for more details: What exactly do you hope to learn from your flashing light? What limitations do you have (assuming you have limitations)? Beyond telling me you want an LED to flash every minute - I have to ask "Why?".

 

As I mentioned several times above, i want to make battery indicator with 3mm green led blink once (1sec) every minute. It is similar to smoke alarm led indicator that blinks once every minute.
Will use 9v and 12v battery.

No one is going to watch a display for a full minute. It will go unnoticed. You would be better to blink it once every 5 seconds or so for a half second.

 

I am making battery indicator and i want the led indicator to blink once (1sec) every minute
I will use 12v battery and 9v battery

A unijunction transistor is probably the simplest solution - some people prefer the "programmable unijunction" which is pretty much a small signal thyristor with the gate at the other end. Its possible to re configure the circuit so it works with a TO92 thyristor like the 2N5061 etc, you can also construct the discrete component equivalent circuit with a cross coupled complementary pair of transistors.

 

I'm still trying to figure out what the purpose of a flashing LED is all about. Suppose you want an LED to flash in representation of a given voltage. As the voltage drops the flash rate drops. That won't tell you anything useful other than the battery is draining. But to have an LED flash once every minute - unless you sit there with a stopwatch and measure and record the interval between flashes - you're not going to learn anything. But since the TS wants a flashing LED - there are plenty of diagrams on Google if all you want to do is make a flashing light. It can be done with a comparator or with a 555 timer. Transistors can do the same. But for a duration as long as one minute; I still don't see why.

Here! flashing led circuit Modify it to suit your needs.

 

This is a combination of a 60 second oscillator with a second timing circuit that puts out a one sec. pulse. (indicator light) lights up for 1 sec.

The whole circuit works as every 60 sec. the LED (indicator light), flashes on for a pulse duration of 1 sec.

It was a fun build project, to see how it could be done,
I did not simulate it, but rather it was built on a breadboard, and it works good, you have to adjust resistor values to get it as precise as needed.

See if this helps any.

 

Here is a 555 timer circuit, gives a 0.1 second pulse every second, change the 100K pot for a 4M7 to give approx 50seconds delay. Lower the 3.3K to set the brightness..

 

This is a combination of a 60 second oscillator with a second timing circuit that puts out a one sec. pulse. (indicator light) lights up for 1 sec.

The whole circuit works as every 60 sec. the LED (indicator light), flashes on for a pulse duration of 1 sec.

It was a fun build project, to see how it could be done,
I did not simulate it, but rather it was built on a breadboard, and it works good, you have to adjust resistor values to get it as precise as needed.

See if this helps any.

View attachment 140243

Thanks will try it and let u know

 

Here is a 555 timer circuit, gives a 0.1 second pulse every second, change the 100K pot for a 4M7 to give approx 50seconds delay. Lower the 3.3K to set the brightness..



View attachment 140285

Thanks, will try it this evening and let you know too

 

I volunteer this blinkable battery checker.

During the time a pulse is applied to the base of the 2N2222 the TL431 voltage tester and LED are enabled.

 

Here is a 555 timer circuit, gives a 0.1 second pulse every second, change the 100K pot for a 4M7 to give approx 50seconds delay. Lower the 3.3K to set the brightness..



View attachment 140285

You can "steer" the on time and off time by replacing the 10k timing resistor with at least one diode and an extra resistor.

Its simply a matter of making Rt lower during either the charge or discharge phase.

 

Here is a 555 timer circuit, gives a 0.1 second pulse every second, change the 100K pot for a 4M7 to give approx 50seconds delay. Lower the 3.3K to set the brightness..



View attachment 140285

You circuit is the simplest and the best!
I change the size of the resistor and the capacitor and it's working perfectly good.View attachment 140310 View attachment 140310
Thank you.
I made the low battery voltage indicator 12v/9v. Your circuit is flashing the led every 70sec (can be changed to any time period) and when the voltage is dropping low then my circuit is getting the Red led ON to indicate the low voltage.

 

Here is a 555 timer circuit, gives a 0.1 second pulse every second, change the 100K pot for a 4M7 to give approx 50seconds delay. Lower the 3.3K to set the brightness..



View attachment 140285

can u help me with this problem too? https://forum.allaboutcircuits.com/threads/how-to-ad-switches-to-2-channel-remote.142561/