Hi!

I bought an TC74HC595P (Toshiba) 8 BIT register... the datasheet:

http://pdf1.alldatasheet.net/datasheet-pdf/view/31766/TOSHIBA/TC74HC595.html


i want to use it without a microcontroller all with switch buttons ( for educational purposes only doesnt need to work 100%) since i am very interested in learning about serial to parallel data in "real time".


like in this tutorial video:

this is my schematic:

http://s10.postimg.org/uscnqogw9/schematic123.jpg




it doesnt work like it suppose to work, it gives me random outputs! :/

is something wrong with:

my schematic?
IC ?
debounce?

i tried to fix this for 19 hours now and nothing
i would appreciate your help...

thanks!

 

You probably need to de-bounce the switches.

 

You mentioned debounce, why didn't you do that? As Blocco mentioned, that's quite likely what it needs.
Here's a debounce circuit that should work for you.
For your requirements connect R1 to GND with the PB connected to +5V.
Leave diode polarity as shown.
You could increase R1 to 47kΩ and reduce C1 to 1μF to reduce the inrush current through the PB.

 

thanks for your help! i made a simple monostable vibrator with an ic555... now my shift register WORKS 100%! i hope this helped someone else with same problem...