Little help :D

[jap]

1,2,3,4,,,,,,,,

Hi eessoo
Congratulations on the third and expected fourth.
-Do you have one working and the two do not work Compare between three will reach a solution.
-Read attention in reply#59 by maiki.
best time
j.

[eessoo]

i replaced the ne555 and it worked

[porkluvr]

Isn't it time you purchased a dual channel oscilloscope so that you can troubleshoot logically instead of guessing?

[eessoo]

i can't afford one
but i can access one
i just don't know how to use it
and i'm in mechanical engineering so i don't really understand how this metal detector work

[porkluvr]

i can't afford one
but i can access one
i just don't know how to use it
and i'm in mechanical engineering so i don't really understand how this metal detector work

For a good explanation of how PI detector work you can read Carl Moreland's Hammerhead article located here .

Instead of 74HC221, Surf PI uses CD4093 to generate sample timing. So, look at the app notes in the attached datasheet for an explanation of how the CD4093 can make a one-shot multivibrator.

[eessoo]

i have a question
what type of coil connector should i use??!
tell me everything about it because i can't find it

[kt315]

...

[eessoo]

thanks
what about the cable it self? anything special about it?