What is the 4511 IC? The 4511 datasheet specifies that this IC is a BCD to 7-segment latch/decoder/driver with four address inputs (DA to DD), an active LOW latch enable input (EL), an active LOW ...

CD4511 is the CMOS version BCD decoder/driver for seven segment common cathode displays ... As a bonus, you can build your own LED display brightness controller circuit using the ubiquitous 555 chip!