ryanleung

i would like to find the datasheet please help me~~~

Any audio amplifier (Mono) circuit can drive a earphone? The impedance of the earphone is about 16ohm. Thank you.

My project is infrared headphone. I would like to supply 9V for my circuit but I do not like to use 9V battery (1.5Vx6). Any suggestion about it. Thx~~~

but this signal can transmit to the receiver using infrared???

the output is like this figure, can i transmit this signal to the receiver?

I want to use the IR diode to transmit the modulation signal to the receiver. I constructed this circuit and connect two IR Diode on the output(Vmod). I tested the IR diode using CRO, there has the modulation signal. But the receiver can not receive the signal. Is this circuit has any problem? thx..... carrier freq.:40kHz Audio: 4kHz

May I design a analog multiplier circuit without AD633 IC? complex?

Hello everybody, I want to make a analog multiplier to multiply two audio signals.

And can you suggest some circuit that can generate the 40kHz? Wien-bridge oscillator?

I want to use the amplitude modulation and the carrier frequency is 40kHz In my project, I would like to tansmit the carrier and the audio signal by infrared. At the receiver side, I would like to use the envelope detector to take the original audio signal.

hello~~~ I would like to multiply the carrier and the audio signal. And I want to design the mixer to multiplier these two signal. What can I do?? can I use the summing amplifier???

hello everybody~~~ I would like to design the circuit.