Fruit Machine

EE JULY/AUGUST 1988 05 This is one of the very few "one-armed bandits" to which the maxim the sole way to win is not to gamble is not ap- plicable. In other words, this circuit does not have a slot for inserting coins: every play is free. Actuation and release of the "PLAY" but- ton, Si, causes the circuit to become operative. Series regulator Ti is driven into saturation by To, which is con- trolled by N2-N7. The outputs of N2, N11, and NI° go high in succession, and disable counters ICs, IC4 and IC3, which are all clocked by oscillator Ni2- N3, and reset by the pulse at their Q3 output. The 3 LEDs driven by each of the counters, therefore, lights cyclically. When a counter is disabled by the high level at its CE input, one of the LEDs in the 3 groups remains illuminated. The 1 30mA 4017 7 010 44 013 44 D11 44 014 R16C 0 N1...N6 = IC 1 = 40106 N7...N12 =IC 2 = 40106 N13...N15 = IC6 = 4073 C2 3x1N414805A 041 03 10 9 6 R12 R13 PB2720 44 SUPPLEMENT 0 SIL -0-0 0-0- BC557 T1 D12 FRUI...