# Opto-Coupler

Discussion in 'The Projects Forum' started by Seehat, Oct 14, 2013.

1. ### Seehat Thread Starter New Member

Oct 14, 2013
12
0
Hi everyone,
i just joined in here but surely i will be here for my uni life..
I just got a uni project on op amps and i cant get it into my head, and just want some help from the engineers out here.
we have to build a circuit where the output is isolated from the input by an opto-coupler that is made from an LED and photo diode.
the input signal will be 2+Asin(2∏ft) V where 20hz<f<20khz and 1<A<4 volts.

we have to complete the following specifications
1) Output - 2A sin(2∏ft+θ)
2) θ should be as small as possible
3) The circuit need to detect when the specified input is applied and indicate by switching on led.
4) The circuit need to switch on led when f of the output(or input) signal is between 970hz and 1.03kHz.
5) the circuit need to minimize the effect of non linearity.

we have no experience dealing with making the circuits and never with the Ac signals.
it would be awesome if someone guide me and get me into the right direction.
THANKS

2. ### THE_RB AAC Fanatic!

Feb 11, 2008
5,435
1,305
What work have you done so far?

Have you decided on a basic block diagram of the circuit operation? That would be a good place to start, then when you post diagram that we can offer suggestions.

3. ### Seehat Thread Starter New Member

Oct 14, 2013
12
0
Yes i have a simple block diagram , i was able to think of

Oct 14, 2013
12
0
anyone ?

5. ### wayneh Expert

Sep 9, 2010
12,123
3,047
Are 3 & 4 two different LEDs, one for an audio range signal detected and the other for a 1±0.03kHz signal?

What does the expression in #1 mean? It's an incomplete expression.

6. ### THE_RB AAC Fanatic!

Feb 11, 2008
5,435
1,305
Thanks for making a start on the block diagram, but your block diagram has large blocks called "Circuit to be designed".

The process of making a block diagram is a critical part of the design (ie decision making). You need to decide what happens within those blocks.

Maybe you should start with just the first block, and decide exactly what that block needs to do? All it shows at the moment is a function generator feeding a signal into the block, and a LED on the output of the block.

djsfantasi likes this.