What are the Alternative Parts for L14F1,LD271 & S20102

[Green Light]

What are the Alternative Parts for

Transistor (L14F1)
Diode (LD271)
IC (S20102)

While I was surfing the net in the hope of finding a Solution to this, I found a Thread Regarding the same in this Site, It was Very Helpful, But not mention the part name (code) wise, I am a newbie to Electronics/Electrical Systems and only have a slight Knowledge of them,I went about obtaining these pieces for many shops but no-one had them,Even shop keepers were not kind enough to provide an alternative.

I am making this Circuit for a Collage Project and must Submit by the Next Week.

The Circuit I am going to make

http://www.electroschematics.com/6161/power-switch-with-infrared-proximity-sensor/

The Old Thread I found on this website

https://www.physicsforums.com/showthread.php?t=476884

Please Help Me,Thanks in Advance

 

[mjhilger]

What do you think those parts are doing in the circuit? How critical is it that you find the exact match? Have you considered finding replacement parts that are similar? The IC is a photo isolated (I believe 4 quadrant) thyristor, do you understand its function?

 

[mjhilger]

Wow, after looking at the old thread, what questions do you have? It seems to have answered what you can use.

 

[Green Light]

What do you think those parts are doing in the circuit? How critical is it that you find the exact match? Have you considered finding replacement parts that are similar? The IC is a photo isolated (I believe 4 quadrant) thyristor, do you understand its function?

Thank you very much for you Comment :) Only a rough idea :(

Wow, after looking at the old thread, what questions do you have? It seems to have answered what you can use.

I want to know whether I can use any solid state (230 V) relay instead of this Sharp one
Also can I use any IR Diode that can be found in the Local Market
Also what is an ideal Transistor instead of (L14F1)