10 channel light bulb sequencer 2011-05-15

[kinjalgp]

kinjalgp submitted a new article:

10 Channel Light Bulb Sequencer - Here is a simple 10 channel light bulb sequencer circuit which you can build up to decorate your ho

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,...

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[shokjok]

You should consider using optos with this circuit. What happens if the triac shorts out?
The AC voltage will then feed the transistor and quickly destroy it. My circuit uses 4N25 optos for this reason. You can substitute the VR with a thermistor, CdS cell or a Theremin-type interface to vary the flash rate.
I used an LED version for a name-in-lights project, with a fixed flash rate of 12Hz.

 

[davidelectrotecnic]

where is skematic...

 

[Battleship]

where is skematic...

I have also used optos in my projects. More specifically, opto-isolatoir triac drivers, with zero-crossing. Likely the best and safest way to separate a DC-controlling-AC circuit.