How to use BCD 74LS47 and connect it to 7 segment ?

[nofnof]

74ls47

hi everybody ,

i working in designing a memory system for AVR microcontroller , im facing a problem in the BCD 74LS47 it consists of 16 pins , 7 outputs , 4 inputs , vcc, ground, and 3 other pins , i have read all the data sheets for this chip and all of them are the same , i connect the 74LS47 exactly as the data sheets , and theres no output
as u see in the figure

the 3 pins LT,BI/BRO, and RBI must be not connected to anything ,
please help to make this chip works
thanks

 

[redhat]

7 segment 74ls47

74LS47 has open collector outputs ,you have to connect each output to a resistance say 150Ω and then to the 7 segment digits which should be a common anode one.

 

[papyaki]

74ls47 and 7 segments

Hi,

LT must connected to +5V and RBI must be connected to +5V.

 

[IanP]

74ls47 seven segment

For a brief test of all segments connect LT(lamp test) to 0V (other inputs do not matter). Once you have all segments tested, tied high LT and RBI. RBO can be left not connected ..

Don't forget about limiting current to each segment by adding adequate resistors(≈220Ω)!!!

 

[redhat]

how to use 74ls47

see
https://www.electronics-lab.com/projects/misc/012/