Ir receiver problem

M

Miltaridis

New Member

• Sep 15, 2010

• #1

Great thanks to ppl helping me on the trasmitter thingy now i require your assistance once more for the receiver part

well here is my schematic
**broken link removed**

my problem is that if i get the transmitter part to transmit at a frequency higher than 256 khz the receiver doesnt seem to work at all . If you have any ideas plz share

Best regards ,

 

MikeMl

Well-Known Member

Most Helpful Member

• Sep 15, 2010

• #2

Are you really trying to power the opamp by putting the 2.2uF capacitors in SERIES with the power pins????

The way you have the inputs of the opamp biased, the circuit would only work if you had split +12V, -12V power supplies. Are you trying to run this on a single 12V supply?

What is the 150Ω load resistor for?

 

Last edited: Sep 15, 2010

M

Miltaridis

New Member

• Sep 15, 2010

• #3

lol perhaps this is the worst shape i have made the 2.2uf are coupling capacitators and are parrarel to the ground and the negative supply of the op amp is coneccted to -12V

mmm i read somewher you put it there for more stable op amp still you think i should remove it ?

 

F

flat5

Member

• Sep 16, 2010

• #4

What op-amp are you using?
Keep the caps.

 

MikeMl

Well-Known Member

Most Helpful Member

• Sep 16, 2010

• #5

flat5 said:

What op-amp are you using?
Keep the caps.

Click to expand...

But connect them properly.

Is this what you had in mind?

 

Attachments

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Last edited: Sep 16, 2010

crutschow

Well-Known Member

Most Helpful Member

• Sep 16, 2010

• #6

The 10pF feedback cap across the 100kΩ feedback resistor gives a -3dB bandwidth of 159kHz, thus the response is down about -5db at 256kHz.

You can increase the bandwidth by lowering the value of either the feedback resistor or capacitor.

Also 150 ohms is a rather large load for the LM217. The maximum output is probably no more than about 3V peak.

 

Last edited: Sep 16, 2010