Timing light control street light control circuit

The timing control of the street light is turned on, and the time interval is turned off. It is necessary to set the time for automatic opening and closing according to the seasonal weather change and the length of the night. Street lamp automatic control requires high reliability of the circuit. Commercially available finished control boxes are available at higher prices. It can be combined with a common device to control the timing switch of the street lamp, which is cheap, stable and reliable.

First, the design plan

The automatic ringing device used by schools and units has the functions of setting digital display, power failure and memory retention, and the circuit is mature and stable and reliable. The time and number of rings can be set arbitrarily. With its timing setting function, its control signal is sent to the counting circuit for programming, and the driving circuit is set according to actual needs, and the relay and the AC contactor are driven to open and close, so as to achieve the purpose of automatically controlling the street lamp.

The street lamp automatic control circuit has timing setting, light control function and manual control function. The new control circuit is shown in Figure 1. The circuit power is taken from the internal DC power supply of the automatic ringer. Because the power consumption of the new control circuit is small, it will not cause the power supply of the ringing controller to be overloaded.

The requirement for the automatic control of the street lamp is as follows: the street lamp is fully illuminated after dark. After midnight, pedestrians are scarce. In order to save energy, half of the street lights are extinguished. When the morning is bright, all the street lights are extinguished. It can be set on the automatic ringer: if it is set at 19 o'clock in the winter, all the street lights are turned on, the ringing time is set to 19 o'clock for 1 minute, and at 1 o'clock at midnight, half of the street lights are turned off, and the ringing time is set to 1 Click to ring for 1 minute, turn off all street lights at 7 am, and set the ringing time to 7 o'clock for 1 minute. Finally, before the next round of the program, set the bell for 1 minute to reset the counting circuit to zero.

Second, the working principle of the circuit

When the first signal is sent by the 19-point ringer, the RI is sent to the (14) leg of the CD4017 counter, and the resistance of the RI can be determined according to the amplitude of the input signal pulse. At this time, the counting circuit starts counting, and Q1 changes from a low level to a high level. After a time-limited circuit composed of R4, VD1, R7, C3, and RIO, the VI is turned on for more than 2 seconds under the action of the pulse signal. At this time. The JKl coil is electrically connected to the JS1 normally open contact closure. The KM1 and KM2 coils are electrically attracted by JKI, and the contacts of JK1 are self-locked through their respective self-locking contacts. The two branches of the main circuit are simultaneously turned on, and the street lamps are fully illuminated.

When the signal set at 1 o'clock midnight arrives, the count output terminal Q2 of CD4017 sends a high level. After the time-limited circuit, V2 turns on, and JS2 pulls in. The normally closed contact of JS2 is disconnected, the KM coil is de-energized, the self-locking is released, the contact of the main circuit is disconnected, and half of the street light is extinguished.

When the signal arrives at 7 o'clock in the morning, the Q3 end of the CD4017 sends a high level, the JS3 pulls in, the normally closed contact opens, and the KM2 self-locks to release the power. At this time, the street lights are all extinguished.

When the reset signal is finally set, the Q4 terminal of CD4017 outputs a high level, and a high-level pulse is sent to the reset terminal via VD4, C2, and R3, so that the counter is reset to zero, and the next-wheel trigger signal is ready. The function of C1 and R2 is that the circuit is powered on for the first time, and a high-level clear pulse signal is sent to the reset terminal CR.

The purpose of setting the time-limited circuit is that when the CP terminal receives the pulse, one output of the counter will remain at a high level, so that the triode and the relay continue to be energized, because the interval between the arrival times of the next pulse is very long, which may cause the triode Or the relay coil is overheated and burned out. After setting the time-limited circuit, the triode relay can only be turned on in a short time, which improves the reliability of the circuit.

The light control portion is composed of a time base circuit NE555 and peripheral circuits. When the photoresistor RC is exposed to light, the resistance becomes small, and the 2 and 6-pin circuits are higher than 2/3 VCC, and the Q terminal outputs a low level. V4 has no base current cutoff and JO remains in its original state. When the night arrives, RC, the resistance value becomes larger. When the potential of pin 2 and pin 6 is lower than l/3VCC, the time base circuit is turned over, and the Q terminal outputs a high level, which is VD8, R14, R15, C7,

The time-limited circuit composed of R16 makes the triode V4 turn on briefly, the JG coil is electrically connected, the normally open contact is closed, and the JK1 coil is electrically attracted, so that the KM1 and KM2 coils are combined with self-locking, and the street lamp is fully illuminated. The timing turn-off of the street light is still completed by the timing turn-off circuit.

The main purpose of the light control circuit is: sometimes it is darker due to weather changes, and the street lamp needs to be turned on in advance, and the light control circuit plays a controlling role. In the case of normal weather, the timing control circuit is used to complete the opening and closing of the circuit. Another use of the light control circuit is to automatically turn on the street light when the night suddenly loses power and then calls again.

The function of setting the manual button is as follows: When the street lamp needs to be repaired during the day, as long as the start button is pressed, the street light will be all turned on. When the switch needs to be turned off, press the stop button and the street light is completely extinguished. Also, when the automatic control circuit fails, you can temporarily use manual to control the street light on and off.

For more variable control procedures, add the same drive circuit and relay to the remaining output of CD4017, and rearrange the combined control program to achieve the purpose of multi-channel control.