Hi Bob

After your last post, I thought about it and have decided to put this Pic version on hold for now.

I would still like to try the 555 and 4017 circuit, if someone can give me one with the functions I had asked for in the begging of this post.

Thanks Again for your help Bob.

George

 

I haven't built this, but I am reasonably confident it will work. You can play around with R1, R2, and C1 to adjust the flash rate and duty cycle.

 

I'm home with the flu, so I gave this a try.

... and it is working ...

Youtube video.

This is all made with big Through Hole components, and you can get all of them as SMD. Which will make it smaller. That's obvious!

 

I'm home with the flu, so I gave this a try.


... and it is working ...

Thanks for breadboarding this. The OP wanted it to be adjustable. What values did you use for R1, R2, the pot, and C1?

 

Thanks for breadboarding this. The OP wanted it to be adjustable. What values did you use for R1, R2, the pot, and C1?

Let's see:

R1:5.6K
R2:8.2K
Pot: 10K
C1: 100uF

You are welcome.

 

Where did the pot go in tracecom's circuit?

Bob

 

R2 is fixed or 10k pot. Aftre thought: As only one LED is on at one time, a single resistor can be used on cathode side of LED's. As long as the ratios stay the same just about any values can be used with R2 up to 1 meg.

 

Where did the pot go in tracecom's circuit?

Bob

I used some of my recent work, which is basically the same as tracecoms, except the pot. See attached image for the schematic.

I added the CD4017BE and some LEDs.

R2 is fixed or 10k pot.

R2 is fixed, 8K2.
Pot is 10K.

 

Hello Everyone

First I want to make sure I thank you for ALL your help. I forget because of memory trouble from car accidents.

Now, could nerdegutta explain his last post. You show a new 555 circuit But with only One LED, am I missing something, where are the other four LED`s? Also to the upper right there is an X1 what does that represent?

If I wanted to ONLY use 4 LED`s instead of 5 what do I have to do?

I look forward to trying to put the circuit together to see if I can get mine to work like in the video. Also that is exactly the the flash rate adjustment and LED flashing reaction I was looking for.

Please include a circuit so I can follow that for my build and your instructions as well. From the last circuit shown, can this circuit work off of 6v OR just 12v?

Thanks again for you help.

George

 

I used some of my recent work, which is basically the same as tracecoms, except the pot. See attached image for the schematic.

I added the CD4017BE and some LEDs.


R2 is fixed, 8K2.
Pot is 10K.

From your new circuit, I see R2 as 5.8k and pot is 5k, can you explain?

George

 

I'll try to explain, as best as I can.

The LED in my first schema, is flashing according to the pulse. The pulse frequency is determined by R2, R3, R4(the pot), and C2. The math about the values are not my strong side. Anyway. This is just a simple one LED flasher. To add more LEDs, we've added the CD4017 CMOS Couner/Divider. The pulse is fed into PIN 14. When the CD4017 gets a pulse on pin 14, it pulses out on pin 3. The next pulse on pin 14, goes out on pin 2. And so on. Search for the datasheet for the CD4017BE.
After all LEDs have been flashed, the next output goes to the reset pin, which is pin 15. And it starts all over again. If you only want 4 flashing LEDs, remove the one connected to the 555 IC, along with its resistor. Also remove LED6 and R9. Move the wire from PIN 1 to PIN 10. We want the 5th output pulse to reset the CD4017 IC.

See attachments for the rest of the circuit.

Hope this helps.

 

Hello nerdegutta

Can you also explain your post #28 that I asked about in my posts # 29 & 30. And what does X1 stand for in the 555 circuit you have there?

Thanks

I want to also know, only 12v for main power or will this work on 6v main power?

I wan to try to put together the Final circuit so that I can try to get my 4 LED`s working like in your video.

If you can, please let me see the Final circuit that gives me the adjustable LED flash rate control as well so I can try to make mine work like in your video.

Thanks Again for your Help.

George

 

The X1-1 and X1-2, is a screw terminal. Like this.

The 555 IC runs on voltages from appx 5 - 15v. Datasheet says absolute max 18v

The CD4017 IC runs on voltages from 3 - 18v, max.

Read both of the IC's datasheet. That is a good practice, and you'd better get used to it.

This circuit will run perfectly at 6v DC, you just have to recalculate the resistor values for the LEDs. Use Ohms law. V=I*R.

I used this to find the values:
(Vs - Vf) / 0.02

Vs = Voltage supply
Vf = Voltage forward
0.02 = LED forward current

(12 - 3.2) / 0.02 =
8.8 / 0.02 = 440

This is for a 12v DC supply.

The values of the resistors around the 555 IC, R2, R3 and R4, are found using google and online calculators. This site is great!
Too bad the author passed away.
Your circuit will look like this. Attachment 1 is the timing circuit, and attachment 2 is the counter circuit. The pictures explain themselves, I hope.

In the 555 circuit and in the 4017 circuit, there is a wire ending in "mid air" called "clock". This is the green wire in the picture of the complete breadboard.

This video shows it all.

 

Hi nerdegutta

Thanks again for ALL your help. One thing, I found a mistake in your last 4017 circuit for the LED resistors value shown. With the sample math you supplied I calculated 440 ohms per resistor, you show 140 ohms for each resistor on the schematic.

Also I had a Good look through the other link you included for 555 reference very educational.

Can you recommend a link so that I can use the program to find the values for the 555 `s R2, R3, R4 and the Capacitor for 6v main power?

Thank You for your help.

George

 

Try to do the math with 6v powersupply.

You just have too use google, and try to look up a guy called bill_marsden on this site. He knows the 555 inside out.

 

Hello again

Yes your right!, When I did the math with 6v I got your value for the resistors.

I know of Mr. Marsden and Yes he is an expert on the 555. I did not know he had a free calculator program to figure the resistors and capacitor needed for the change in 555 circuit.

George

 

Hi nerdegutta

George again. I have googled and looked through Mr. Marsden site LOTS of information. I have also google search for a calculator program to use to find the values of R2, R3, C2 BUT every circuit I have seen is Astable or Monostable 555 BUT I can`t see how to calculate the R4 variable resistor value. How is that done?

Please let me know since I have the part values for the 555 with 12v I would like to have the part values for 6v so I can go to the electronic store tomorrow and buy them to try at home. Can you help me?

George

 

You want an Astable circuit. The values for R2, R3, R4, and C2 have nothing to do with your supply voltage. Their values will be the same for 5-15 volts. They have to do with the timing.

The resistors for the LEDs, are dependent on the supply voltage. These you have to calculate using Ohms Law, as mentioned above.

At least to my knowledge.

 

Hi nerdegutta

I think I did not ask you the question correctly. I did the math like you showed earlier, that was pretty easy.

What I would like to know is how to find the values for the resistors and capacitor and the adjustable resistor for the 555 with a 6v main power; R2, R3, R4 (adjustable) C2 from your last circuit.

Thank You nerdegutta

George

 

Hello Again

I think I FINALLY understand what you are trying to say to me. I did the math and if I understand you, the ONLY value that changes with 6v and 12v is the LED protection resistors, the other resistors and capacitor around the 555 , their values are the same including the adjustable resistor.

So for 12v at the 555, R2-5.8k, R3-8.2k, R4 adjustable-5k, C2-100microF
At the 4017 LED protection Resistors- 440ohm each

For 6v at the 555 the same value Yes / NO ???
At the 4017 LED protection Resistors - 140ohm each

Is this Correct ?

And before I forget, Thank You ALL especially nerdegutta for your help.

George