The post explains a simple, compact, 220V, 120V transformerless light chaser circuit which can be used for illuminating mains operated lamps in a sequential chasing manner.
Main Technical Features
The chasing effect can be altered by means of pot controls. The system can be used as a decorative lighting during festive seasons like in Christmas and Diwali. The idea was requested by Mr. Ashish.
As usual, the proposed Diwali, Christmas light chaser circuit is built around the ubiquitous IC 4017 which is a divide by 10 Johnsons counter/divider IC.
It basically has 10 outputs in the order 3, 2, 4, 7, 1, 10, 5, 6, 9, 10 pinouts which can be made to shift in a sequential manner, one after the other by providing voltage pulses at its pin#14.
The above outputs can be either connected with LEDs for acquiring an LED illuminated chasing effect or can be terminated with triacs for driving mains operated lamps in the same fashion, as shown in the diagram below.
Referring to the circuit diagram, we can see that the IC1 is clocked or pulsed at its pin#14 through a transistorized AMV stage.
Circuit Description
This transistor astable multivibrator produces alternate high and low pulses at the collectors which can be witnessed by the blinking red LED.
With every high pulse or blink of the LED, the output of IC1 sequences to the next subsequent output pin and continues to do this with every subsequent pulses at pin#14.
When the output reaches pin#11, the IC resets and the sequence returns to pin#3 for commencing a new cycle.
Here, since the outputs are terminated to gates of triacs, the triacs conduct with the same sequence illuminating the connected AC lamps producing a running or chasing effect.
The speed of this chasing or sequencing can be altered by simply adjusting the two pots VR1, VR2 appropriately.
The circuit runs from direct mains through a capacitive power supply and is therefore not isolated from lethal mains current, observe extreme caution while testing/handling the circuit while it's in an uncovered position.
Circuit Schematic
CAUTION: NO MAINS ISOLATION PRESENT....HANDLE WITH EXTREME CAUTION TO AVOID SHOCKS, AND FATALITY.
Parts List
R1, R2, R3, R4, R5----R15: 1K
VR1, VR2 = 100k
C1, C2 = 10uF/25V
C3 = 474/400V
C4 = 100uF/25V
D1 = 12V zener, 1 watt
D2 = 1N4007
R16 = 10 ohms, 2 watt
Triacs = BT136
IC1 = 4017
T1,T2 = BC547
LED = red, 5mm
Michael says
can I use only 5 outputs and ignore the rest. that is, I use only pins 1234&5
Swag says
yes you can, just make sure to connect the 6th pin with pin#15…pin#15 should be disconnected from the ground and connected to the 6th pin
Anonymous says
Dear Swagatam,
Please tell us how to program as per our choice for RGB LED string lights for decoration. Also can I sync colour effect as per music beats, drum etc.
Thanks!
Swagatam says
Hi, please tell me what kind of programming do you plan to implement, by the way if it's too complex then you may have to go for a microcontroller design.
also please specify, for music trigered RGB what kind of mixing do you intend to have??
Pratheesh N says
dear brother i need how to design led running in different styles eg forward, revs,waterflow,
Swagatam says
Pratheesh, that will require a micrcontroller, can be difficult using an ordinary circuit.
Pratheesh N says
where to buy 8mm led in whole sale
Swagatam says
from Lamington Road in Mumbai
Moseur rahman says
Hi, Swagatam Majumdar.
I start a business as a wadding planar. For that I need to decorate the place with lights. Because of I am new in this business, I have to take the others lightning set and give them too much rent as a return. Now I decide, make my own lightning set with many varieties. but I know a little about this led circuit, and I can't find information as much as I need over the Internet. I hope you can help me with this. So please let me know if you can. it's really important for me
Swagatam says
Hi Moseur, If you provide with all the technical specification that you require for the lighting, I may try to suggest….
but make sure the lighting pattern is not complex…
Kesava Raj says
Common ground line means ….Neutral connection
Swagatam says
the line which may be connected with the right side pin of the triac/SCR, it could be phase or neutral whatever but this line should be also connected with the negative of the circuit….this will make the circuit extremely dangerous to touch and therefore caution will need to be maintained.
Kesava Raj says
If we use transformer input voltage 12v 1A to ICS…and 230v to bulbs & Triac…it will work ?….
Swagatam says
yes it will work but make sure to connect the circuit negative with the SCR or triac common ground line.
Bubai says
Can I use readily available LED chain/string in the market which is equipped 474k 400v cap transformer-less power supply within a small thin box without any filtering electrolytic capacitor. If yes Is any OpctoIsolator like MOC3021 required?
Can I use any other SCR like BT169 or MCR100 instead of BT136 if yes which pin to what ?
In BT136 is PIN T2 to neutral T1 to LED chain one wire and other wire of LED chain to LINE(phase) of 220v AC. is it correct or T2 to Phase…
Swagatam says
You must build exactly as shown in the diagram, I cannot suggest or recommend some other unknown circuit integration with the above circuit.
BT136 center pin goes to the load, left side pin to ground….and the right side pin is the gate
arun kumar says
Can you please tell me how can I connect two CFL bulbs in Christmas start which lights one at a time
Swagatam says
I'll try to upadte the details in a new article soon!!
basit momin says
50 led in series on one channel……..
Swagatam says
Ok you can do it, but you will have to use a 0.47uF/400V capacitor at the junction of all the led strings, and the other end of the capacitor to one of the mains inputs….the other mains input will connect with the all the points marked ground in the circuit and the triacs
basit momin says
50 led in series on each channel
basit momin says
Hello sir how i can run the led in above circuit as i know that the circuit is designed for for 220v bulbs but by making some changes can we run led on this circuit if yes then how many leds can run in series
Swagatam says
basit, how many LEDs do you want to run on each channel
Sarah Lina Saad says
Sir, can i use ic 4028 and 4516
Swagatam says
sorry no, only 4017 or 4022 would work here
Rolf says
how many bulb can i use in this circuit? in series and parallel
Swagatam says
depending on the triac rating you can add more bulbs in parallel on each string
NAS NAS says
What is lec in circuit?
Swagatam says
It's the LED
Preston Jose says
How Can we increase the no. of leds
Swagatam says
the above circuit is for 220v mains bulbs, not leds.
nobert singh says
actullly i am a 12 small kid. once i went to a temple and saw a running light
LEDs in that was just getting on and of then i thought it would be a multi wave ocillator circuit which have heavy duty transistors and is switching even and odd number LEDs that were creating a running effect can i make a running light like that for diwali decoration?
Swagatam says
i'll try to find this circuit for you, and inform you if i find it.
nobert singh says
No sir actually i observed that the LEDs placed in odd number places and LEDs placed on even number places were acting as the two loads in a disco light circuit i am having which i got from Bal Bhavan,Delhi it contains two transistors switching two loads in the runing light i saw in temple the two loads were even number and odd number LEDs connected in parallel connection so can i use that circuit by using two high power transistors?
Swagatam says
Hi Nobert,
yes you can do it, use 8050 transistors, it will be enough for handling the leds in parallel, also include resistors for each LED string
Seelamsetti Manikanta says
hi bro
can i connect low power leds at the outputs of decade counter ? any modification should be made in the power supply ?
Swagatam says
yes you can connect leds at the outputs of the IC..no mods required.