Homemade Street Lamp Voltage Stabilizer Photoelectric Controller

This article introduces the automatic voltage-stabilizing light control system designed and manufactured independently by the author. The system consists of a light control circuit and an automatic voltage-stabilizing circuit. After years of operation, it has been proven to be reliable and worth introducing. This article reviews the design intent, installation, commissioning, and use.

The author's unit has hundreds of street lamps, with a total power of more than 5KW. The mains voltage is as high as 240-250V due to the proximity to the substation. The excessive voltage frequently causes street lamp bulbs to burn out, and replacing bulbs has become a common occurrence. In addition, manually controlled street lamps are scattered in locations and inconvenient to operate.

Therefore, the author designed and installed an automatic voltage-stabilizing light-controlled street lamp system.

1. Design Intent

In order to reduce the manual labor of water and electricity managers, the author designed a light-controlled street lamp device, which automatically turns on the street lamp when night falls and automatically turns off the street lamp when dawn comes, so that the street lamp will not be suddenly extinguished when lightning strikes at night. The 555 time base integrated circuit is used as the core of the light-controlled circuit to achieve this function.

In order to reduce the shortened service life of street lamps due to excessively high mains voltage, and waste money and manpower, the author has designed a voltage stabilizing device that has voltage stabilizing performance that does not fluctuate with the power supply voltage. When the power supply voltage changes within the voltage range of 230 to 250 volts, the output voltage change value of the voltage stabilizing device does not exceed 0.5% of the set output voltage. In order to save electricity and increase the service life of street lamps, the output voltage of the voltage stabilizing device must be adjusted within the range of 150 to 220 volts, and an AC voltage regulating circuit with a single junction trigger thyristor with negative feedback is used to achieve this function.

In order to facilitate manual control of the street lamp power supply during electrical testing and maintenance of street lamps, the author added a manual control switch to control the contactor of the light control device, so that the contactor can be controlled both manually and automatically.

The circuit schematic is shown in the figure

2. Installation and debugging

1. Installation requirements: Install the electronic components on a 150×150 universal circuit board according to the circuit diagram, and install the photoresistor on the panel of the power distribution iron box, and connect it to the circuit board with an insulated soft wire. Thyristors, insulation boards, AC contactors, and automatic air switches are all installed in a 600×800×200 power distribution iron box. The thyristor needs to be equipped with a radiator, with sufficient heat dissipation space, and ensure its insulation from the box.

2. Debugging requirements Before debugging, check the installation quality and insulation conditions, and then turn on the power switch to carry out debugging work.

(1) Debugging of the light control device: Cover the photoresistor with a shading object and measure whether the light resistance and dark resistance of the photoresistor meet the requirements. The potentiometer RP1 can be adjusted to adjust the illumination of the street lamp.

(2) Debugging of the automatic voltage regulator Close the manual test switch S. Power on the automatic voltage regulator and use a multimeter to measure the voltages at points U1 to U9 ((1) to (9)). All voltages should be normal. Adjustment of the upper limit of the output AC voltage: Adjust RP2 to make U5 zero and adjust RP3 to make the output AC voltage 220 volts. If this value cannot be reached, it can be achieved by changing the resistance value of R1 1. Adjustment of the lower limit of the output AC voltage: Adjust RP3 to make U6 maximum and adjust RP2 to make the output AC voltage 150 volts. If this value cannot be reached, it can be achieved by changing the resistance value of R7 or R9. Adjustment of the output AC voltage: First adjust RP2 to make U5=0 and adjust PR3 to make the output AC voltage 220 volts to determine the setting value of PR3: then adjust RP2 to make the output AC voltage drop to 180 volts. Thus, the setting value of PR2 is determined. In this way, the working voltage of the incandescent lamp is determined to be 180 volts.

3. Voltage stabilization performance test: Use a voltage regulator to adjust the input voltage of the system within the range of 230 to 250 volts, and observe the change of the AC output voltage. If it does not exceed 0.5% of the working voltage, it meets the design requirements.

3. Usage Evaluation

The use of the automatic voltage-stabilizing light-controlled street lamp system has two outstanding features: (1) It greatly reduces the burning of bulbs. This was verified by comparing the two months before and after use. Before the transformation, the night voltage was 245 volts, the total number of bulbs in the street lamps was 136, and the maintenance was done once every two weeks. A total of 125 bulbs were replaced in a month, accounting for 92% of the total number of bulbs. After the installation of the system, only 3 bulbs burned in the month, accounting for 2% of the total number of bulbs, which was a 90% decrease from the month before installation. (2) The bulb voltage is stable and saves electricity. Before use, it was 245 volts, and after use, the system output voltage was 180 volts. This can save 27% of electricity.