Hi
guys, my problem is with displaying 6 & 9. the upper bar of siX doesn't light & the lower of nine doesn't too. could u show me the connections between 7447 & 7-segment. I connected each output of 7447 to the respected of 7-segment, I don't know where the problem is...
thanks

 

The 7447 has outputs called a, b, c, d, e, f, &g. Those tie to the similarly labeled inputs on the display. The complication is in limiting current in each segment. A '47 has active low outputs, so the display must be a common anode type. If it uses the same =5 supply as the logic, each segment drive must have a resistor of about 330 ohms in to to limit the current safely.

 

The Fairchild Semiconductor data sheet for the DM7447A seems to suggest the upper horizontal bar on the 6 and the lower horizontal bar on the 9 are not lit when those numbers are requested.

 

The Fairchild Semiconductor data sheet for the DM7447A seems to suggest the upper horizontal bar on the 6 and the lower horizontal bar on the 9 are not lit when those numbers are requested.

This is consistent with the Texas Instruments' datasheet for the SN7447.

 

Thanks guys very much, I checked the datasheet, 6 & 9 are by default lightening that way,,,,,,
many thanks