hand sensor

[bigkim100]

I would like as simple as possible circuit that can detect a human hand from anywhere from 6 to 12 inches.
It needs to trigger a 555, and run on either 5 or 9Vdc.
I tried the attached schematic, and unless you actually have to touch the antenna to trigger.
Thanks in advance for any help,
Kim

 

[bigkim100]

I did find a schematic...what yall think?

 

[Audioguru]

C5 will probably prevent radio signals from activating it. It will not work if there is no AC electricity near the human.
It will need a 1.2V input signal to begin turning on but needs much more sensitivity to do what you want.

 

[Harald Kapp]

Do you need to detect specifically a human hand, or any object?

• For any object a radar sensor can be used.
• For any human body part a PIR sensor can be used.
• If you need to specifically detect a hand, I think you'll have to use a camera and a vision processing system to distinguish between a hand and any other object. A raspberry Pi plus camera plus some programming can do the job.