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LED Chaser Circuit --Need Help

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Jeez

New Member
Need help for my Chaser circuit

Hi , I am planning to create an full cycle of electronic circuit , need your help to achieve my hobby goal .

What i am planning to do is

1)Phase 1 --Schematics Design.

2)Phase2--> Online simulation.

3)Phase3-->Design PCB Layout//SMT Layout .

4)Phase4-->Testing .

About myself , My degree was electronics engineering , unfortunately i moved into software coding for 15 years ..and now at 37 age i want to start my electronic passion ..hope i get help on getting back what i lost years back and succefully achieve my hobby project .

Lets start with Phase1 --Schematic diagram

Below is my circuit design copied from http://www.eleccircuit.com/led-chaser-by-ic-4017-ic-555/

led-chaser-by-ic-4017-ic-555.jpg
http://www.eleccircuit.com/wp-content/uploads/2007/05/led-chaser-by-ic-4017-ic-555.jpg

Have few questions as below

1)Can the above circuit work with single AAA 1.5V battery ? if not

2)My Input is gonna be 1 AAA battery 1.5 volt. , how to convert it to 6-9volts range ?

3)Is there any best step-up 1.5v to 9v convertor schematic ?. It should be small in size and cheap in price .

4)My final out put will not have 10 LEDS , instead will have 5 LED's , is it best to use IC 4017? or do you guys have any other IC in mind .

Size is the utmost factor for my circuit , it should be as small as possible .

Once i get answer for above question , will proceed with next questions .

Hope my questions are not stupid .

Thanks
GJ
 

spec

Well-Known Member
Most Helpful Member
Hi Jeez,

Nice to see you on ETO.

Which part of India are you from? If you put it next to 'Location' on your user page it will display in the box next to your posts. Knowing where you are helps us to give better answers.:)

Your age is stated as 15 not 37 on your user page.

Good luck with your objective of getting into electronics, but your programming experience will be invaluable too. There is a forum on ETO for microcontrollers/microprocessors.:)

Like you, I lost touch with electronic circuits for a long time, but have done a few circuits now since joining ETO.

You ask if the chase circuit will work from a single 1.5V primary cell: The short answer is, no.:eek:

(1) LM555 supply rails are, 4.5V to 16V. http://www.ti.com/lit/ds/symlink/lm555.pdf
(2) CD4017 supply rails are, 3V to 18V. http://www.ti.com/lit/ds/symlink/cd4017b.pdf

The CMOS version of the LM555, the LMC555 will operate from 1.5V to 15V though. http://www.ti.com/lit/ds/symlink/lmc555-md8.pdf

But even though theses integrated circuits are specified for low supply rails, their performance degrade below around 5V, and the LM555 is not really happy below 9V supply rails.

If you absolutely need to operate your circuit from a single 1.5V battery, your best bet, is to use a boost (step up) switching voltage regulator. You can either make your own boost converter from a transformer (wind yourself) and a few other components or buy a converter off-the-shelf (cheap on ebay). Building your own boost converter would be an interesting exercise though.

I haven't looked at the other aspects of your circuit yet.

spec
 
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ericgibbs

Well-Known Member
Most Helpful Member
hi Jeez,
Comparing the size of an AAA battery + boost converter + the AAA battery holder I would choose a 9v PP3 style battery, job done...;)
E
 

spec

Well-Known Member
Most Helpful Member
Hi again Jeez,

you need to put a resistor in series with each LED to define the LED current.

In addition, you need some high frequency ceramic decoupling capacitors: 220nf, or larger, directly across the supply pins of the 555 and 100nF, or larger, across the pins of the CD4017 supply pins.

You also need a 10nF ceramic capacitor from pin 5 og the 555 (control voltage) to 0V.

If you are using a battery, you would also be wise to increase the electrolytic capacitor on the input supply rails to 1,000uF or higher.

spec
 
Last edited:

Jeez

New Member
hi Jeez,
Comparing the size of an AAA battery + boost converter + the AAA battery holder I would choose a 9v PP3 style battery, job done...;)
E
Hi ,
Hmm this makes sense a lot ...how did i forget the AAA battery holder.. looked quick turnaround for CR2032 button cells , but it has less life , less current(10ma) and voltage drops and high cost compared to AAA Battery . so CR2032 is out of scope .

This leads to further question
1)What would be the minimum voltage 555 timer accepts , as per the circuit i pasted it says 6v -9v ..some circuits i have seen 5v input to 555 timer .
2)for the above circuit how much current u think its required --assuming 1 led on's at 1 sec with 3 sec time delay to trigger other LED ON
3)Boost coonvertor - there is an <1 $ IC LM2621 readymade chip ..how do you rate this chip compared to traditional coil circuit http://www.ti.com/product/LM2621Is there any IC s there any IC

After reading this article , http://www.eetimes.com/document.asp?doc_id=1279094 it makes lot of sense to me, i need i will go for 1 single AAA battery [boost convertor (step-up from 1.5 v to 9 v) + chaser circuit].
Unless if someone convience me alternate solution .

Again the size looks bulky to me (i dunno the reason why i dont like bulky components , i love compact and slim .
 

eTech

Active Member
Hi

Also keep in mind that each of the CD4017 outputs can only drive about 6.8mA. This will affect your choice and brightness of the LEDs.
 

Jeez

New Member
Hi Jeez,

Nice to see you on ETO.

Which part of India are you from? If you put it next to 'Location' on your user page it will display in the box next to your posts. Knowing where you are helps us to give better answers.:)

Your age is stated as 15 not 37 on your user page.

Hi Spec ,

Have updated my profile , its not allowing to update DOB ..have contacted the admin


Good luck with your objective of getting into electronics, but your programming experience will be invaluable too. There is a forum on ETO for microcontrollers/microprocessors.:)

Once i get my basic skills , i will surely get into Microprocessor and controller , this were my favourite subjects along with VHDL and VLSI .

Like you, I lost touch with electronic circuits for a long time, but have done a few circuits now since joining ETO.

Great to have like minded people ..Thumbs Up !!


You ask if the chase circuit will work from a single 1.5V primary cell: The short answer is, no.:eek:

(1) LM555 supply rails are, 4.5V to 16V. http://www.ti.com/lit/ds/symlink/lm555.pdf
(2) CD4017 supply rails are, 3V to 18V. http://www.ti.com/lit/ds/symlink/cd4017b.pdf

The CMOS version of the LM555, the LMC555 will operate from 1.5V to 15V though. http://www.ti.com/lit/ds/symlink/lmc555-md8.pdf

But even though theses integrated circuits are specified for low supply rails, their performance degrade below around 5V, and the LM555 is not really happy below 9V supply rails.

If you absolutely need to operate your circuit from a single 1.5V battery, your best bet, is to use a boost (step up) switching voltage regulator. You can either make your own boost converter from a transformer (wind yourself) and a few other components or buy a converter off-the-shelf (cheap on ebay). Building your own boost converter would be an interesting exercise though.

After reading this article , http://www.eetimes.com/document.asp?doc_id=1279094 it makes lot of sense to me, i will go for 1 single AAA battery [boost convertor (step-up from 1.5 v to 9 v) + chaser circuit].
Unless if someone convience me alternate solution .


I haven't looked at the other aspects of your circuit yet.

Now i am in jinx bcoz of this below article
i found an more cheaper easier way to achive the same module using this schematic-
http://www.deeptronic.com/simple-running-led-led-chaser-circuit-using-3-transistors/
I feel this schematic is more chaper and compact and effective compared to my earlier 4016 chaser circuit . your comments are highly appreciated



spec
 

audioguru

Well-Known Member
Most Helpful Member
Many solar garden lights light a color-changing LED IC with about 4.5V produced by a simple voltage stepup circuit when powered from an AAA rechargeable battery. You could use a higher power but lower voltage (than the CD4017) SN74HC4017 IC and a Cmos 555 to work from the 4.5V.

About 11 years ago I designed chaser circuits that brightly light the LEDs and the AA battery cells last for months. Red LEDs use two AA alkaline cells for 3V when new and blue and bright green LEDs use four AA alkaline cells for 6V when new.
Instead of having an LED always lit by the 4017 I made a circuit that blinked each LED for about 30ms then pauses the 3 or 4 revolutions of chasing with no LEDs lit for about 2 seconds to save battery power. I haven't tried powering one circuit from a garden light voltage stepup circuit but one AAA alkaline or Ni-MH cell should last for a few weeks.
 

spec

Well-Known Member
Most Helpful Member
Also along the lines of saving power, you can use high efficiency LEDs which are bright with just 2mA of current as opposed to the standard LEDs which require 20mA.

By the way, a very low voltage input converter (below around 1.5V input) is known as a 'Joule thief' and are great fun to experiment with. In fact, there is a whole sub-culture of Joule thief experimenters. There is also some Joule thief information on ETO.

My advice for batteries would be to go for a Lithium Ion (LiIon) rechargeable battery. For small portable applications I normally use a RCR123 cell, but that might be a bit big for your application (see table of LiIon battery sizes below). A single LiIon battery has a terminal voltage of 3.6v and has a very high energy density compared to other battery types. LiIon batteries also have a much more stable voltage than the normal non-rechargeable batteries you buy over the counter.

spec

2016_10_30_iss01_ETO_LiIon_BATTERY_SIZE.png

 
Last edited:

audioguru

Well-Known Member
Most Helpful Member
The datasheet for most ICs shows its minimum supply voltage. For an old fashioned ordinary NE555 or LM555 it is 4.5V.
For a Cmos LMC555 its minimum is 1.5V but the voltage of an AAA cell drops to less than 1V over its life.
 

Jeez

New Member
thanks for all your replies , i am working on it ...and i am confident i will achieve the circuit in compact size ..any question i will shoot here ..
 

spec

Well-Known Member
Most Helpful Member
Here is a complete LED chase circuit for you to consider.

2016_10_30_iss01_ETO_LED_CHASER_VER1.png

NOTES
(1) A singe 3.6V LiIon battery will power the circuit.
(2) The current consumption is negligible apart from the LED current which is set at around 2mA each.
(3) The circuit is designed for high brightness, low current LEDS but can be modified for higher current LEDs
(4) Decoupling capacitors are not shown.
(5) Both chips are DIL (not surface mount) for easy assembly
(6) The variable resistor adjusts the frequecy of the integrating oscillator and thus the speed that the LEDs chase.
(7) The timing capacitor should be a tantalum type.

DATA SHEETS

http://www.ti.com/lit/ds/symlink/sn74ahc132.pdf
http://www.ti.com/lit/ds/symlink/sn74hc4017.pdf
 
Last edited:

Jeez

New Member
Here is a complete LED chase circuit for you to consider.


NOTES
(1) A singe 3.6V LiIon battery will power the circuit.
(2) The current consumption is negligible apart from the LED current which is set at around 2mA each.
(3) The circuit is designed for high brightness, low current LEDS but can be modified for higher current LEDs
(4) Decoupling capacitors are not shown.
(5) Both chips are DIL (not surface mount) for easy assembly
(6) The variable resistor adjusts the frequecy of the integrating oscillator and thus the speed that the LEDs chase.
(7) The timing capacitor should be a tantalum type.
thanks a ton ..this circuit was not in my list ..first will start the 555 and 4017 circuit then will start this ..thanks lot for your help spec ..i feel blessed i am regaining my passion on electronics ..
 

spec

Well-Known Member
Most Helpful Member
No probs Jeez,

The form on ETO is that we all post circuits but it is up to you to choose the one that you want to go with.:)

(there is just one point though, the 555 is not too happy below about 7V to 9V supply lines)

spec
 

RODALCO

Well-Known Member
And if you want to use only 5 LED's connect the reset (pin 15) to the output which would have driven LED 6.
 

Tony Stewart

Well-Known Member
Most Helpful Member
Considering the CD4017 has an output driver equivalent to 1k at 3V and 300 Ohms at 15 V, current is going to be sparse. But in spec 's improve design the difference voltage between Vbat and Vf of LED is limited in current by Ohm's Law ... ΔV/Rs=I.

So for Red/Yellow Vf=2-2.1 with Vbat=3.6V
(3.6-2)/20mA= 80Ω. and his 560Ω will last longer at 1.6V/560=2.9mA which may be enough using 10Cd 5mm Red LEDs now producing ~ 2.9/20*10,000mcd=1,450 mcd
 
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Tony Stewart

Well-Known Member
Most Helpful Member
Yes, the 74HC4017 and other HC Cmos ICs provide plenty of current at 3.6V and 5V supply voltages:
You can't say that about worst case 3.6 since it is no longer specified.

Iol min [email protected] (rise) for Vcc=6V @25'C or Zol=67 Ohms
Iol min [email protected] (rise) for Vcc=4.5V @25'C or Zol=100 Ohms
Iol min = 10 mA @2V (rise) (est.) Vcc-3.6V is no longer spec'd @3V or Zol=200 Ohms from previous datasheets, which I have it was 1K for CD4xxx but the 74CD4xxx is lower Zout

It seems they have relaxed the current specs for 74HCxxx low voltage where users must choose 74ALCxxx if they want high currents at 3.6V
upload_2016-10-31_19-35-35.png
upload_2016-10-31_19-40-34.png
 
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spec

Well-Known Member
Most Helpful Member
There is another variable in the equation now: Texas instruments have dropped HC for many of their CMOS logic chips and moved on to AHC, for most functions, but retained HC for the 017 decade counter.

AHC has twice the speed of HC and half the power, and I think the output is tailored to reduce ground bounce.

As a rough rule of thumb, it seems that at 25 Deg C junction temperature and 5V Vcc, HC and AHC can source and sink 8mA, worst case.

In practice though, the maximum source and sink currents for CMOS logic chips seems to vary widely from manufacturer to manufacturer and batch to batch.

spec

http://www.ti.com/lit/sg/sdyu001aa/sdyu001aa.pdf
http://www.ti.com/lit/an/scaa034c/scaa034c.pdf
http://www.ti.com/lit/ml/scla013d/scla013d.pdf
 
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audioguru

Well-Known Member
Most Helpful Member
I have made many chasers using 74HC4017 ICs and all brightly light the 1.8V red LEDs using a 3V battery that drops to 1.6V when it still works but the LEDs are dim, and using a 6V battery for 3.4V blue and bright green LEDs that drops to 3.8V when the LEDs are dim. The datasheet for the SN74HC4017 says its absolute maximum allowed output current is 25mA so I limit the current with a resistor to 23mA.
 
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