Pulse Generator Produces 3-Phase Output

This is a schematic diagram of a three-phase pulse generator circuit. This circuit produce 3 phase overlapped output similar with 3 phase  AC powerline, you can say this circuit produce the DC pulse version. This schematic diagram shows two CMOS inverters and CMOS 4-bit shift register as the circuit’s  main components. The shift register is configured as divide-by-6 Johnson counter, providing glitch-free outputs. Square-wave clock signal should be provided by external source to drive this circuit, and this clock source should have frequency 6 times of desired output frequency. Here is the schematic diagram of the circuit:

[Circuit’s schematic diagram source: seekic.com]