I want to use ultrasonic sensor in my new project and I decided to use SRF04, but I can't find it; now I want to find SRF04 circuit till I make it myself.
I become very thankful if you help me to find SRF04 circuit.
Fair enough. Try an internet search using "SRF04 circuit" or "SRF04 schematic". I found the information you require there. You will also find alternative ultrasonic sensors there that are available locally if you now cannot locate the SRF04. More information is available from the ultrasonic sensor manufacturer's website.
Now, I would be interested in how you found out about CR4.