A little over a year ago I built a metal detector based off of mircemk's Simple Sensitive IB Metal Detector with 2xNE555. It worked great and I had a lot of fun building it and digging stuff up. Even found some coins! I made a few design flaws in the build that I'd like to fix, but will probably build an entirely new one in the future now that I own a 3d printer.

Ever since then I have wanted to build a 555 timer out of discrete components. I recently revisited Rudraksha Vegad's Giant 555 Timer project and was inspired to design a 555 timer PCB with all SMD parts (Except the connectors).

All Resistors are 0805 for easier hand soldering. I can solder 0402 and 0603 but would be really tedious with so many pieces.

At this point this project is just an idea. I think my final goal would be to rebuild my metal detector using two of these, and another board that has the potentiometers and other components. We'll see.

I pretty much copied Rudraksha's schematic and resistor values, considering he built this already I figured going with his should work.

Components:

• 17 NPN Transistors    ( MMBT3904 )
• 8 PNP Transistors      ( MMBT3906 )
• 6 Diodes                    (  1N4148WS  )
• 3 5k Resistors            ( 0805 )
• 5 100k Resistors        ( 0805 )
• 4 150k Resistors        ( 0805 )
• 2 4.7k Resistors         ( 0805 )
• 2 470ohm Resistors  ( 0805 )
• 10 10k Resistors         ( 0805 )
• 1 8 pin Header
• 1 8 pin screw terminal