mirror image of layout

[dj_devil]

i bymistakely etched pcb with a mirror image of layout.so ic ne555 which m using cannot be connected with pins at proper places.is there any other option except making it all again?

 

[ericgibbs]

hi,
You could bend out the 555 legs and surface mount it.

 

[dj_devil]

i dont know much about surface mounting nor i have tried it.

 

[ericgibbs]

i dont know much about surface mounting nor i have tried it.

Do you have a picture of the PCB [ copper face] that you could post.??

 

[Mike_2545]

Mount the 555 on the other side of the board, soldering might be a challenge...if that does not work you could "dead bug" the chip (glue it down to the board upside-down and connect short jumpers off its leads)

 

[KeepItSimpleStupid]

I did that one with an amplifier. Fortunately I was able to use the layout with minor mods.

The "dead bug" approach should work. You could probably bend the pins out straight, and solder to a 16 pin header.

 

[dj_devil]

**broken link removed**

 

[dj_devil]

i am sorry but i am not able to upload any images.don't know why??

 

[crutschow]

What type of image did you try to upload? When you go to the "Manage Attachments" window it will show the type of files you can upload and their maximum allowable size.

 

[dj_devil]

check the layout.its a simple 555 circuit.

 

[ericgibbs]

check the layout.its a simple 555 circuit.

hi,
There appears to be tracks missing from the artwork.??
I am assuming your image shows the copper side of the pcb.??

Do you have a schematic to post, so that we can check it against the artwork.?

 

[dj_devil]

hi,
There appears to be tracks missing from the artwork.??
I am assuming your image shows the copper side of the pcb.??

Do you have a schematic to post, so that we can check it against the artwork.?

i got this schematic from internet.i am making it all again.can u just tell me its working?i know that when a metal or magnet is brought near inductor its frequency changes but is it a tank circuit and what 555 does?

 

[ericgibbs]

i got this schematic from internet.i am making it all again.can u just tell me its working?i know that when a metal or magnet is brought near inductor its frequency changes but is it a tank circuit and what 555 does?

hi,
IF this is the copper side of the pcb, mount the 555 on this side and top solder the 555 pins.
The other components can be placed on the other side of the pcb.

The circuit produces a 'tone' in the speaker which will vary a little in frequency as a metal object is brought near to the 10mH inductor.

 

[dj_devil]

is it a tank circuit?what is the use of 555?

 

[ericgibbs]

is it a tank circuit?what is the use of 555?

Depends what you mean by a 'tank' circuit.???

The 555 is configured as an Astable, it produces a square wave output which drives the speaker via the 10uF cap.

The frequency of the square wave is dependent upon C2, C3 and the 10mH, so as the inductance of the 10mH changes due to a close metal object, so does the sound you hear.

 

[dj_devil]

Depends what you mean by a 'tank' circuit.???

The 555 is configured as an Astable, it produces a square wave output which drives the speaker via the 10uF cap.

The frequency of the square wave is dependent upon C2, C3 and the 10mH, so as the inductance of the 10mH changes due to a close metal object, so does the sound you hear.

how will you calculate the output frequency?

 

[ericgibbs]

how will you calculate the output frequency?

You would use the formula F= 1/[2*Π*√LC]

In the circuit shown thats. Note the 2.2uF caps are in series ie: 1.1uF effective.

.01  
1.1 ×      
.000001 ×
--------------------------
0.000000011 =
 
sqrt(0.000000011) 
--------------------------
0.000104880884817 =
 
0.000104880884817  
6.28 ×
--------------------------
0.000658651956651 =
 
0.000658651956651 1/x
1,518.25253064551379 =

approx 1.5KHz

EDIT:
Added a simulation to show the circuit running.