What is the differences between the static power dissipation and the switching power dissipation in a CMOS inverter and what parameters that affact the switching power dissipation?

How can i increase the transmit distance?
now, it can work 6-8 inch only

Maybe the phototransistor is being saturated by visible light. Is the range better when it is dark?

Yes

And I have a some question to ask you.  My oscillator can not adjust the frequency to 38kHz.  I use 220nF capacitor and 180uH inductor and I can not decrease the frequency anymore.

How can i increase the transmit distance?
now, it can work 6-8 inch only

The circuit can sucessfully received the signal.  If I want to add the Automatic Gain Control(AGC) to the receiver, how can I do?

The red circle voltage measured is not 5.9V, it is 9V same as the VCC
Is it no current though the IR LEDs?

Ok, I will try it.

thanks

how about the distance, the signal is very weak

hello audioguru~~
I have are few question about my project.
1.   I constructed your receiver already.  And I amplified the signal using opamp, then it was connected to the audio amplifier.   But the sound is very weak.  I try to adjust the volume but the sound is also weak.  I don't know how to increase the signal.   And the maximum distance only have about 5cm that is very short.
2.   I constructed the envelope detector (R=40ohm, C=0.1uf) and connected to your receiver output but the envelope detector output have not output signal.

thanks

The resistor is 40ohm and the capacitor is 0.1uF. The frequency is 38kHz.
Is it right?

f=1/(2*pi*R*C)

should I amplify the signal again?(tansmitter and receiver)

Your IR receiver probably has a strong output at 38kHz now but you can't hear a frequency so high. Therefore the receiver needs to feed an AM detector diode and filter to recover the modulation.

The transmitter circuit has two very important resistors that need adjustment. See my sketch.

You are using Amplitude Modulation. Noise is fluctuations in amplitude that the circuit is designed to receive. You should be using FM instead, for low noise.

two resistors?
the AM detector means the envelope detector?

Hello audioguru,
I constructed your transmitter and the receiver circuits already.

hello audioguru.
My AM transmitter output signal is 9.2Vp-p. And I changed the R1, R2, C and R3 to 2.7kohm, 10kohm, 0.01uF and 1Mohm.

I think the base of the oscillator should be modulated then it can connect to a common-emitter LED driver transistor.
An oscilloscope will show you what the transmitter is doing.

sorry, I don't know your mean. can you draw a circuit to me, thanks!!!