A roulette wheel electronic circuit can be designed using a 4046 PLL containing a voltage controlled oscillator or VCO, two phase comparators, a source follower, and a Zener diode that is used to produce a low-frequency, pulsed output of about 40 Hz. The VCO's frequency range of this roulette wheel electronic circuit is determined by R6 and C2, which can be altered by varying the voltage at pin 9.
The rising voltage causes the frequency to rise from zero to threshold and remain at that frequency as long as SI is closed. When S1 of roulette wheel electronic circuit is opened, C1 discharges slowly through R1 to ground and the voltage falls toward zero. The output of 4046 PLL at pin 4 is connected to the clock input of U2 which is a 4017 decade decoder/driver ( at pin 14 via C3). U2 4017 decade decoder/driver sequentially advances through each of its ten outputs (0 to 9)—pins 1 to 7, and 9 to 11—with each input pulse. As each output goes high, its associated LED is lighted, and extinguished when it returns to the low state. Only eight outputs are used in the circuit, giving two numbers to the spinner of the house. The circuit can be set up so that the LED's lights sequence or you can use some staggered combination; the LEDs grouped in a straight line or a circle.
This circuit project must be powered from a simple 9 volt DC power supply .