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10 Channel Light Bulb Sequencer

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kinjalgp

Active Member
Project Level: Intermediate
Here is a simple 10 channel light bulb sequencer circuit which you can build up to decorate your house.
OPERATION
The circuit consists of 2 sections:
1) Oscillator: The oscillator is built around IC555 wired in astable mode. The frequency of this oscillator is around 1 Hz (or slightly less than that) which can be increased further by decreasing the value of potentiometer VR1. The oscillator frequency determines the speed of effect. Higher the frequency, higher will be the effect speed.

2) Sequencer circuit: The sequential lighting of bulbs is achieved using Jhonson Counter IC 4017 which has 10 decoded outputs. The output of 4017 increments by one on rising edge of each clock pulse from IC555. In the circuit the fifth output Q4 of 4017 is connected to its reset pin to reset the sequence after every four clock pulses. Here only four channels are shown but it can be extended upto 10 channels using all the outputs of 4017. In this case the reset need to be connected to Ground. For channels less than 10 the output one greater than required number of channels should be connected to reset pin to reset the cycle as soon as counter counts one greater than the required channels.

The output of 4017 drives the base of NPN transistors (BC547) through 1k resistors. The LED in the collector loop of each transistor indicates the active channel. The emitter current of each transistor further drives the gate of Triacs (BT139) thereby turning them ON and supplying power to the lamp loads. Those who have 120V AC mains in their countries can also use this circuit without any changes. Many number of bulbs can be connected in parallel on each channel provided the maximum load on each channel does not exceed 3500W for 220V operation and 1760W for 110V operation.

:arrow: NOTE: DO NOT TOUCH ANY COMPONENT OF THE CIRCUIT WHEN IT IS ACTIVE AS IT MAY BE AT A VERY HIGH POTENTIAL AND MAY PROVE FATAL. I DO NOT GIVE GURANTEE OF ANY KIND. EXPERIMENT AT YOUR OWN RISK.

Feel free to give your feedback!
 

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kinjalgp

Active Member
Thanks Electromaster! It seems you saw this project 2 years after posting!
:lol:
 

kinjalgp

Active Member
Rami00972 said:
Can i replace the BT139 with T106M1 and which one is the better
Thanks
No you cant use T106M1. Its a SCR while BT139 is a TRIAC. SCR will only conduct in one half of the AC cycle thereby producing only half of the actual intensity from lamps.
 
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advautomation

New Member
switching the neut with the BT139

Is there a reason that you are switching the neut with the BT139? Can I switch the Hot? This project is just what to doctor ordered!!
 

kinjalgp

Active Member
abida said:
can u plz give te schematic diagram of ur project?
Its already attached with the first post !... Click on it and you'll be able to download it.
 

kinjalgp

Active Member
jumides said:
hi kinjalgp,
I see schematic, but what happen to 4017, if BT139 goes wrong(short circuit) ?.
Well, it totally depends upon the type of failure of BT139. If there is leakage from gate .... it will blow up 4017 in worst case. However I haven't seen such kind of failure.
To avoid triac failure, never connect load beyond its rated capacity.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
kinjalgp said:
To avoid triac failure, never connect load beyond its rated capacity.
And never use them to feed bulbs, because when the bulb fails it almost always takes out the triac at the same time.

Bit difficult for a light sequencer though?.
 

shokjok

Member
The 4017 would quickly self-destruct. I built a similar circuit using MCT2 optos and T106 triacs to control Christmas lights ( up to 200 per triac, fused). A smaller version using 2N3904s alone turned on LEDs as a mini name-in-lights project, with 6 recipients.
 

kinjalgp

Active Member
And never use them to feed bulbs, because when the bulb fails it almost always takes out the triac at the same time.

Bit difficult for a light sequencer though?.
The 4017 would quickly self-destruct. I built a similar circuit using MCT2 optos and T106 triacs to control Christmas lights ( up to 200 per triac, fused). A smaller version using 2N3904s alone turned on LEDs as a mini name-in-lights project, with 6 recipients.

I doubt if that would happen ! When bulb fails, it becomes open circuit ! How will that affect the TRIAC ??
I have been using this circuit for years now with quite a lot bulb failures, never had to replace a TRIAC or 4017 yet!
Can you explain ?
 
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Gayan Soyza

Active Member
I’m away of this BT series TRIACs. For running lights its ok but when it comes to sensitive light dimming (Phase Controlling) this series acts poor.

I’m using TIC216 or BTA16-600B because they don't seem to suffer from any dv/dt problems.
 
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