Chasing Color Light Controller

Chasing Color Light Controller

This section introduces a simple and easy-to-make chasing colored light controller. Just string three groups of colored lights in a space and arrange them appropriately to create a chasing flowing water effect.

Circuit Principle

The circuit of the chasing colored light controller is shown in the figure. The circuit consists of an oscillator, a thyristor switch circuit and a power supply circuit.

The power supply circuit is composed of VD4, VD5, C4 and C5. After the power is turned on, a stable DC voltage of about 6V can be obtained at both ends of capacitor C4 to supply power to the oscillator. The oscillator is composed of transistors VT1-VT3, and its oscillation is formed by the feedback of coupling capacitors C1-C3. After the power is turned on, the three transistors are intermittently turned on and off, and at any time, one transistor is always turned off and two transistors are turned on. H1-H3 are three groups of colored light strings, and whether they are lit depends on whether the thyristor VS is turned on. The turning on of the thyristor is determined by the corresponding transistor state. If the transistor VT1 is in the off state, its collector outputs high level, and the diode VD1 is turned on, then the trigger current is injected into the thyristor VS1, so that VS1 is turned on, and the first group of colored light string H1 is lit; if the transistor VT1 is turned on, its collector outputs low level, VD1 is turned off, VS1 loses the trigger current, and when the AC passes through zero, it is turned off, and the light string H1 is extinguished. From the above analysis, we can know that when VT1~VT3 are oscillating, there is always only one transistor in the cut-off state, and the state changes alternately, that is, the cut-off tube changes in a cycle from VT1→VT2→VT3→VT1→..., so the light strings H1, H2, and H3 are lit in turn. As long as the colored lights in the light strings are properly arranged in space, a chasing water effect can be formed.

Component Selection

VT1~VT3 can use 9013 type silicon NPN transistors, and the characteristics of the three tubes are required to be as consistent as possible, with a β value of about 100. VD1~VD3 can use 1N4148 type silicon switching diodes, VD4 can use 1N4001 type silicon rectifier diodes, and VD5 can be a 5V, 1/2W voltage-stabilizing diode, such as 2CW54 type. VS1-VS3 uses MCR100-8 type and other 1A, 600V small plastic-sealed unidirectional thyristors. The three groups of light strings H1~H3 can use commercially available colored electric bead light strings. If the light strings are connected in parallel, 220V, 5W colored bulbs should be used in parallel, and the power of each group of light strings should be controlled at 100W or less.

R1~R6 all use RTX-1/8W carbon film resistors, C1-C4 use CD11-25V electrolytic capacitors, and C5 requires a CBB-400V polypropylene capacitor.

The printed circuit board of the colored light controller is shown in the figure. The size of the printed circuit board is 90mmX50mm. This circuit is relatively simple and can work normally after the power is turned on. If you want to change the chasing speed of the light string, you should also change the capacity of capacitors C1~C3. The larger the capacity of C1~C3, the slower the chasing speed, and vice versa. Readers can adjust it according to their needs.