what is IC GL3274 for?

and another question. what is a relay for?

A GL3274 is a preamp for a photo-diode in an IR remote control receiver.
A relay is an electric switch that has a low voltage low power control input and its contacts can switch a high current or high voltage.

the IC is a preamp for remote controls....

and for the relay question.... GOOGLE is your friend!!!!!!

I see. What is the function of a preamp?

legolaslee said:

I see. What is the function of a preamp?

Click to expand...

A preamp amplifies a low level signal so it is at a high enough amplitude to be useful.
The output signal from a photo-diode is at an extremely low level. The amplifiers in the GL3274 have a gain of about 10,000. Then the signal is limited, bandpass filtered and AM detected which drives a Schmitt trigger at the output.

Look at the datasheet that has all the details:
**broken link removed**

Oh! Thanks! I appreciate it.