This system of sequential lights for shop windows, discotheques, stores, does not use integrated circuits, which facilitates its assembly by the inexperienced. The complete 6-step circuit, but which can be extended, is shown in the figure. 6 identical steps are used, each with basic elements of an SCR and a transistor. The system operates as follows: each transistor is used to excite or trigger the SCR. At the base of each transistor, we find an electrolytic capacitor that, when charged, causes the transistor to activate the SCR. The value of this capacitor determines exactly the activation time of each stage. For uniform operation, the capacitors can be the same, 470 uF, but in addition to changing the value of one or the other, you can also change the overall speed by changing them all. The values of these capacitors can be between 100 uF and 2 200 uF.
