Hi I am a 1st year electronics student and I'm trying to make a light bulb dimmer circuit for my presentation but I am not sure what SCR I should or if my circuit is possible. I'm planning on using a 3v light bulb for my circuit. Is it possible? what SCR should I use?

 

Hi I am a 1st year electronics student and I'm trying to make a light bulb dimmer circuit for my presentation but I am not sure what SCR I should or if my circuit is possible. I'm planning on using a 3v light bulb for my circuit. Is it possible? what SCR should I use?

Any SCR will work. A filament lamp will have an inrush current of 10 times its running current, so don't choose one that is too small. Look for one with a gate current suitable for your trigger circuit.
But don't forget that they will only work on AC if you want to make a dimmer.
And also forget that they will drop 1Volt, so if you have a 3V AC supply, you will only have 2V left for the lamp.

 

I don't believe you will find an SCR around a 3 volt rating. You need to consider the current draw.

 

Using a SCR at low voltage makes no sense since AK drop will be about 0.8V at least, so it will lead to very poor efficiency.
I would not use a SCR even at 12V.
Use mosfets or Bjt-s instead.

 

One thing to consider with SCRs is the holding current. Your load must consume more current than that, otherwise the SCR will not latch.

Do you know the load current? Based on that we could make device recommendations.

 

Is this DC or AC? I either case, the SCR is not the best option.

 

What is the motivation of selecting 3 volts??
At that voltage you can use a transistor to vary the current and dim the 3 volt bulb. Is the plan to use battery power???
There are a lot of details missing.