Use CD4011 and CD4518 to make colorful circular decorative lights

The circuit of the colorful circulating decorative light is shown in Figure 3-22. It consists of a power conversion circuit, a color clock pulse signal generator
and a light color changing control circuit.
    After the 220V AC power is bridge-rectified by VD1~VD4, on the one hand, it supplies power for the lantern circuit; on the other hand, it is step-down and
current-limited by Rl, voltage stabilized by VD6, isolated by VD5 and filtered by cl, to provide a stable DC voltage of about lov for the control circuit. . Al and
peripheral components form a clock pulse signal generator, in which NAND gates I, II, RP, R3 and C2 form a
multivibrator , and NAND gates III and IV form an RS flip-flop to shape the pulses generated by the oscillator. , and then sent
to the clock pulse CP input terminal of A2 by NAND gate IV . A2 is a CMOS digital integrated circuit with a dual synchronous addition and counting function.
The positive pulse sent by the NAND gate IV is binary encoded inside it, and causes the states of the three output terminals Ql, Q2, and Q3
to undergo cyclic combination changes. The corresponding colored lights turn on and off accordingly. According to the principle of three primary colors of light, 7 colors
of light can be produced externally, as shown in Table 3-1. For example, when the first clock pulse arrives, the Ql terminal of A2 outputs a high level ,
the one-way thyristor VS1 is turned on, and the colored lamp Hl emits red light; when the second pulse arrives, the Q2 terminal of A2 outputs a high level. level, VS2
is turned on, and H2 emits green light; when the third clock pulse arrives, Ql and Q2 of A2 output high level at the same time. Both vsl and
VS2 are turned on, Hl and H2 light up at the same time. According to the color mixing principle, the external light turns yellow...{When the 8th clock pulse
arrives, QI~Q3 of A2 all output low level , H1~H3 All is turned off for a moment; at the same time, the Q4 terminal of A2 outputs a high level
, and its signal is directly sent to the eight clear terminal R, which resets the internal circuit of A2; when the 9th clock pulse is sent to A2, the
above process is cycled.