Three-way flashing light string circuit (4)

It is a street flashing light string controller with a novel light string jumping method . It can make the strings light up one by one,
turn them off together, and then light up one by one and turn them off again, and so on. The main control device
    of this fE circuit is a four-operation amplifier I, M3?4 integrated circuit , and its four operational amplifier parts are connected in the form of a comparator. The threshold level of the comparator , that is, the level of the non-inverting input terminal is determined by dividing the voltage by R, ~R, and the inverting input terminal of each comparator is connected to the negative terminal of the battery. After power on, the voltage H at both ends of the return capacitor changes suddenly, (. The negative terminal potential is close to 0V, the power supply voltage is the highest, each comparator outputs low level, the thyristors VT1 ~ VT3 are all turned off, and the lights F - E3 are all extinguished. .As charging proceeds, the potential of the negative terminal of (t begins to gradually decrease. When it drops below the threshold level of the non-inverting input terminal A of the first comparator (that is, lower than the level of pin ⑥), pin ⑨ outputs a high level. , VTI is turned on, and the light string El lights up; when the potential of the negative terminal of C: continues to drop below the threshold level of the non-inverting input terminal of the second comparator (that is, lower than the level of pin ⑩), pin ⑧ outputs a high level , VT2 j has been turned on, and the light string EZ is lit again. By analogy, when the =th comparator pin ⑦ outputs high level, V113 is triggered to turn on again, and F3 is lit. At this time, 1FI~F3 are all powered on Emit light. When (j negative terminal potential continues to drop below the threshold level of the fourth comparator J phase input terminal (that is, lower than the ③ pin level), ① pin outputs high level, and the transistor VT4 is turned on at this time , f: The stored charge will be quickly discharged through VT4, so that the voltage at both ends of Cz is zero, that is, its negative terminal rises to the 9V power supply voltage, and all comparator forks output low level . VI] - VT3 park loses triggering The currents are all turned off, the lamp El~yo goes out, and the power supply charges G again through R, so that the potential j of its negative terminal begins to decrease... Over and over again, F1 - E3 will light up one by one and go out together, and so on. The cycle rate of the light string     in this circuit is mainly determined by the charging time constant of R., such as R., which can be adjusted . The resistance of the voltage divider R. - R, will determine the length of time each light string is on. VTl -VT3 can use ordinary MCR100-8 and other small plastic-encapsulated unidirectional thyristors. El-E3 can use commercially available colored light strings, and the power of each light string is preferably below 100W or IOOW.