• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

74HC194 4 bit bidirectional shift register

Status
Not open for further replies.

max1525

New Member
I'm using the 74HC194 shift register in my circuit and currently using two switches to simulate data and a clock pulse. The data is entered at the serial data input (DSR) and shifted right, therefore mode control inputs S0 is high and S1 is low. The reset is connected to Vc due to it being active low and all unused parallel data inputs are connected to ground. However when I hold the data switch and send one clock pulse all data outputs go high instead of just the output from the first flip flop. The data switch is then released and the clock is triggered again, I would expect the output of the second flip flop to go high and the rest to be low, however all outputs go low. Any help to what this maybe will be greatly appreciated, I've attached a copy of the data sheet below.
https://assets.nexperia.com/documents/data-sheet/74HC194.pdf
 

crutschow

Well-Known Member
Most Helpful Member
Sounds like you don't have the clock switch debounced.
A mechanical switch will bounce numerous times when closed, which looks like multiple clock pulses to the circuit.
Look up "debounce circuit".
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top