555-timer circuit to turn on light for 1 hour

Wendy

Joined Mar 24, 2008
23,415
I tend to be one of the fans of the 555 on this site, Indeed I have written a whole chapters of the text book offered through AAC. The real problem isn't the chip, it is the capacitor, even a little excess leakage on the cap that would normally be considered negligible will kill the circuit, you may find it necessary to audition capacitors to find one that works, there is a chip called a 4060 that is a bunch of flip flops in a package that tends to work first time for long duration timers, being CMOS like the 7555 it also works at low power supply voltages. As it happen I am one of the many folks her who like to mentor people just starting out. If you would like my help I am offering it. To tag me just type @Wendy in you post, and I will be flagged to view the post, This willwork for any members name.I like to Write how to articles, to teach as I figure most people are like me and want to do it themselves.

Wendy's Index
The 555 Projects
555 Monostable
 
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djsfantasi

Joined Apr 11, 2010
9,156
By the way, what’s the button for!

I don’t know. It might take 5-10 lines of code. Way too complicated...:rolleyes:

I’m offering help with the ATTiny85
 

Wendy

Joined Mar 24, 2008
23,415
@Collin55 is not the best source of advice on this forum, as he likes to market his ideas for a profit against the rules one this site. It will get him banned one day. And today was the day
 
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danadak

Joined Mar 10, 2018
4,057
As previously stated use ATTINY85 (8 pin dip UP) or Arduino Nano board (~ $ 1.50, has xtal
on board for accurate timing) and Ardublock to program -



upload_2019-3-18_20-49-40.png


Nano board size of your little finger approximately.

Note more pins available to handle buttons, turn on other stuff.
Also A/D to make turn on a function of V, like a T sensor for example.
Or use an I2C sensor......

Ardublock takes your drag and drop objects and converts to code and passes
that on to Arduino IDE to program part or board. Also the code shown debounces
the button so no false triggering occurs. Upon power up no false triggers occur from
the UP, pins in Hi Z state. You would add external R from LED pin to ground, if
you are driving a transistor to turn on LED, to make sure it stays off until code
starts to execute as designed.

Fun stuff.

Regards, Dana.
 
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Wendy

Joined Mar 24, 2008
23,415
I've said this many time it is easier to buy a 2 cent resistor and 30 cent capacitor than to buy programming hardware and learn programing. I just banned Collin 55 for trying to sell his preprogramed hardware from OZ. Personally I think it is like "come to the dark side, We have cookies!". If the TS is trying to figure something out it is a distraction. I would fully agree controllers are the way to go, but not for a first time project. reminds me of another user stating to me he didn't need resistor for an LED as he was using PWM, First you learn the basics, then you fly.
 

AnalogKid

Joined Aug 1, 2013
10,986
@Collin55 is not the best source of advice on this forum, as he likes to market his ideas for a profit against the rules one this site. It will get him banned one day. And today was the day
Back when I reentered this site, he told three different people that they were too stupid to understand any answers they would get to their questions - In One Week. As a new guy on the site, I tiptoed around his arrogance and misinformation for a while, until I saw how some of the older hands treated him. Then, no more tiptoeing. Gonna miss him.

ak
 

danadak

Joined Mar 10, 2018
4,057
Across the USA kids are using the Scratch/Blocky language to do programming.
Earliest I have seen so far is 8 year olds. Is it complete and deep, no, its a start.
The kids are not drowning they are flourishing.

This morning on news Marines, with NO electronic background working with
these graphic languages and programming simple bots with cameras to evaluate
on site for weapons, injuries, .....And programming alterations on site for particular
site characteristics.Their analog skills probably suck, but will they start picking
up stuff as they go, I would bet on it.

Virtually everyone on the planet knows how to use a calculator, they are already programming
with basic concepts. Memory, operations, functions.....

Most tools these days free, and low cost for boards. And tons of training videos all over the web.

I agree with basic to a point, in fact if you look at the Arduino revolution people and kids are
learning some of the basics as they get more involved in interface. You see this evolution in
many videos on web. The evolution of knowledge has us all jumping into the middle of the time
line, not the beginning. I do not want to go back to Ohms period of discovery, even though I
think his experimental physics one could learn from. I just want to go far forward of E = I x R.

Closing I think one can start at any one of multiple points in our field and learn.


Regards, Dana, processors and digital and analog the greatest.
 
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Ya’akov

Joined Jan 27, 2019
9,069
Perhaps to some.
But it's likely all Greek (no offense) to a newbie to electronics.
Starting out in electronics by programming is like jumping into the deep end when learning how to swim. :rolleyes:
People can come to hardware by software, with programmers suddenly building real world interfaces for their programs; or to software by hardware, as in engineers computerizing their designs.

People will lean on what they know the most, sometimes creating awkward or inefficient solutions, but in cases like this, it’s not “easier”, necessarily, to do something with a 555 and some passives than it is to use a simple IDE and some code. The latter might actually be more understandable considering the need to grasp RC constants and the like.

I can’t see any preference in approach here save the one the approacher finds most comfortable, but considering the project goal, the very long delay and the imprecision the analog solution is likely to provide, I’d lean towards the digital solution myself.

If the beginner is starting with nothing, they don’t have an easier time with circuits than code automatically.
 

AnalogKid

Joined Aug 1, 2013
10,986
People will lean on what they know the most, sometimes creating awkward or inefficient solutions,
"I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail."
Abraham Maslow, The Psychology of Science: A Reconnaissance, 1966

Hence, my tagline.

ak
 
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Ya’akov

Joined Jan 27, 2019
9,069
Hence, my tagline.

"I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail."
Abraham Maslow, The Psychology of Science: A Reconnaissance, 1966

ak
People with hammers can drive nails as well as screws and think they got it over on people with screwdrivers until they drive to drive machine screws.

There’s a point in that, if you can dig it out.
 

Wendy

Joined Mar 24, 2008
23,415
I say this wearing my moderator hat.

Please stay on topic, one of my jobs here is to protect beginners and people new to AAC from people hijacking their threads, You will note I stopped responding until Collin55 tried his sales pitch waiting for the TS @rayrivera to reply, this thread belongs to him. I will continue to monitor this thread whether the TS comes back or not.
 
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Bernard

Joined Aug 7, 2008
5,784
Many years ago I wondered how long a 555 could output a pulse, Made it to 3 hours with two caps of 3000
mF & 20 m ohm leakage & 10,000 mF @ 21 m ohm leakage. It took about 3 days to adjust to an even 3 hours.
 

Travm

Joined Aug 16, 2016
363
People with hammers can drive nails as well as screws and think they got it over on people with screwdrivers until they drive to drive machine screws.

There’s a point in that, if you can dig it out.
Have you ever driven a screw with a hammer? Screws make terrible nails.
Interestingly enough I have driven a nail with a screwdriver by inverting it and using the handle and weight of my hand.

Sorry, I had to.

This topic as a learning experience to me is two basic choices. Does the TS want to learn about analog electronics first? Or digital?
I find basic programming to be far simpler than analog electronics, and I've never even used an Arduino.
 

Thread Starter

rayrivera

Joined Mar 22, 2017
10
@Wendy Thank you all for contributing to this thread. I would answer by saying I would prefer analog first but am open to all options. I'm sorry it took me so long to get back to it. I did purchase (10) tlc555cp. I would like to be able to push a button and have a white LED light up for up to an hour. It could be 30 mins- 1hour. I just want it to turn off by itself to preserve the battery. The battery will be a 3V button cell battery I'm am also looking to keep the circuit small, 15mmx55mm or about 5/8"x 2 1/4".
 

crutschow

Joined Mar 14, 2008
34,280
I did purchase (10) tlc555cp. I would like to be able to push a button and have a white LED light up for up to an hour. It could be 30 mins- 1hour.
So you will need a timing RC time-constant of about 3600 seconds.

Try connecting the timing capacitor to V+ instead of ground.
That way any capacitor leakage current is in parallel with the charging resistor and will not prevent it from charging (actually discharging) to the 555 trigger point.
 
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