Speed regulator - for disco lights

. . for disco lights It is interesting to be able to vary the run-off speed of the disco lights featured in our February 1984 issue. Not many changes to the circuit then published are needed, and even those are small. The additional circuit illustrated is connected to that of the disco lights via A . . . F shown in figures 1 and 2 (the latter is the com- ponent layout of the printed circuit for the disco lights). Preset P1 in the disco lights circuit should be set to maximum resistance because it is connected in parallel with any of the four presets in the present circuit. When the disco lights are being pro- grammed, the four new channels should, of course, be included. When a logic 1 is programmed, the buffer outputs (N42 . . . N45) are low and they must therefore be in- verted in N1 . . . N4 to be able to drive the CMOS switches. Itispossibletoapplyalogiclevelto more than one of the inputs A . . . D at the same time. Because of the equal values of presets P1 . . . P4, a four-bi...