make a smart solar powered street lamp - 12w solar led street light

by:Litel Technology     2019-07-31
make a smart solar powered street lamp  -  12w solar led street light
This guidance describes the design of an easy-to-manufacture smart solar street lamp using GreenPak.
With solar energy and batteries, it can effectively provide energy for any type of light without causing trouble.
Solar street lamps are novel because they can be turned off. -
In case of power failure, it can still work normally.
It also enables electricity to be used for other purposes.
The "intelligent" part of the street lamp can automatically light up when moving objects are detected.
The final design is a truly energy-saving solar intelligent street lamp.
This design can be extended to larger power lights, such as lighting for infrastructure lighting, or to very small lights, such as lights for beautifying and illuminating roads, landscapes and gardening.
In all of these applications, GreenPak's design will remain similar.
For this project, Silego's Greenpak configurable mixed-signal integrated circuit(CMIC)has been used.
The three key functions of programming in chip are: 1. -
Motion Induction 2-
Solar induction 3-
Battery-level inductive motion induction saves electricity. Light is allowed to rotate only when any moving object is detected.
To do this, a passive infrastructure-Red (PIR)
Sensors have been designed.
The PIR motion sensor has a separate output pin and VCC and GND pins.
The PIR sensor basically detects the infrared radiation level.
Once a change in radiation level is detected, it sends a signal notifying the change.
The sensor is one of the most commonly used sensors in motion detection. (see Fig. 2)
Ambient solar Induction solar panels are used to sense ambient light.
A solar panel provides full output in full direct sunlight and zero output in the absence of light.
These conditions can then be converted to the appropriate level to generate the digital input pins of the CMIC.
By using a simple voltage dividing circuit, the 18 volts generated by solar panels can be converted to 3 volts.
3V signal for high voltage-
The level logic input of SLG46140 V CMIC.
Battery power monitoring and charging battery power monitoring is also an important aspect of the system.
In this design, a sealed wire-Acid (SLA)
Batteries are in use.
SLA batteries have wide applications, high reliability and high cost-
Effective batteries.
Compared with batteries with other chemical components, the charging method of secondary batteries is much simpler.
SLA batteries need to be charged at a constant current equal to 0. 1C (
Here C = the capacity of the battery at full charge, ampere-hour)
The voltage is about 1.
It is 5 volts to 2 volts higher than the rated output voltage.
Therefore, the charging circuit can also be simpler.
It is important to note that at full capacity, the 12V SLA battery will provide an open-circuit voltage of about 13. 2 volts.
When discharging, the open-circuit voltage measured by the battery is slightly less than 12V.
But because our CMIC can't measure such high voltage, these need to be converted to acceptable range.
Similarly, a simple voltage divider is used to divide the voltage into about 800 mV, indicating that the battery has been discharged and about 1150 mV indicating that the battery has been fully charged.
Then these voltage levels are input into SLG46140 V CMIC and compared with their analog comparators.
As we will see in the next section, these comparators play a critical role in the overall project implementation.
By downloading greenpak software to view pre, greenpak IC can be easily programmed to control intelligent solar street lights. -
Make intelligent street lamp design document.
Connect the GreenPak development kit to the computer, insert the unprogrammed SLG46140 V GreenPak IC into the development kit socket, and then click on the program.
The integrated circuit will be automatically programmed into an integrated circuit, which will control intelligent solar street lamps.
Once the IC is programmed, you can save the IC in the development toolkit socket for easier access to pins, or mass production. You can create a small PCB board to access the chip.
Now that Greenpak IC has been programmed to control intelligent street lights, you can jump to step 4.
If you want to better understand and modify the internal circuit of the intelligent street lamp design file, step 3 will give you an overview of how Greenpak's intelligent street lamp design file is programmed.
The GreenPak schematic diagram for implementing the design is shown in the figure. 5.
Description of the sales used:
Pin 3: Digital input pin for detecting the presence of ambient light. -
Pin 4: A digital input pin for detecting motion or the presence of an object. -
Pin10: Analog input pin for battery power monitoring. -
PIN12: Digital output with 1Xpush-
It is used to control the pull-out mode of LED.
PIN14: Digital output with 1Xpush-
Pull the output mode to control the charge current entering the battery.
3 - Bit and gate: 3-
The bits and doors in this design ensure that the lights are turned on only when all conditions are met.
Conditions such as the detection of nearby motion, the presence of surrounding sunlight and the required battery power are the three bits that determine the output of the gate.
Battery power monitoring: two analog comparators(ACMP0 and ACMP1)
Monitor battery voltage.
As mentioned earlier, two 800 mV and 1150 mV voltage levels are used to determine battery status.
If the measured battery voltage drops to 800 mV or less, the comparator(ACMP0)
The output is zero.
This output is fed into 3-
Input and gate, in turn, output is zero, and lights are turned off when the battery voltage is detected to be too low.
The high level voltage is measured during charging and will be used as a voltage divider input comparator for CMIC pin 10 input. (ACMP1).
Once the voltage level reaches or exceeds the reference voltage set on the reverse input(
In this case, 1150 mV)
Comparator output is high.
Once we reach the level we want, we need to cut off the battery charge, so it's low. -
Level output is required, so a simple inverter is used.
Input of solar cells: As mentioned earlier, when there is no ambient light, the output of solar cells is zero/digital. -Low signal.
Because lack of sunlight is one of the conditions for turning on street lights, we need to convert it into digital signals. -
High, so our Hemen also exports a high.
Therefore, an inverter is also used here.
Use counters as a means of prolonging the output cycle: In the above design, counters(CNT0/DLY0)
It is also used to produce a certain delay when pin12 of CMIC turns off the signal.
This results in an expected delay and avoids fast output switching. (see Fig. 6)
Use of counters as a means of prolonging output cycles: In the above design, counters(CNT0/DLY0)
It is also used to produce a certain delay when pin12 of CMIC turns off the signal.
This results in an expected delay and avoids fast output switching. (see Fig. 6)
This section describes the use of external circuits required to drive larger loads (such as 10W LED lights) and recharge batteries.
In order to create the most efficient and energy-saving circuit, MOSFET has been used in contrast to the ordinary BJT.
This will result in faster switching time and higher/lower power consumption.
Battery Charging Control: IRLZ44N HEXFET Power Supply MOSFET(
Similar mosfets, such as fqp30n06l, can also be used.
Used, it is n-
Channel-enhanced MOSFET.
This kind of MOSFET is specially designed to work at gate voltage level. (3V and 5V)
Small controllers and integrated circuits are easy to produce.
The data table of MOSFET describes the threshold gate to source voltage. (Vgs(th))
For leakage current ID of about 1 ampere, it is about 3 volts.
According to the electrical specification of pin 12, our small CMIC can easily achieve this. (
Similar to pin 14).
LED lamp control: Similar to charging control circuit, this part of our project also uses IRLZ44N HEXFET MOSFET to switch 10-watt LED, which is the main lighting source.
Because we want to control a 10-watt LED with a 12V battery, we need to be able to provide about the current. 0. 8 Amp.
The circuit is shown in Figure 8.
These circuits can be connected to a circuit board or connected through a dead circuit.
This paper introduces the design of intelligent street lamp with SLG46140 V Greenpak CMIC as the main control element.
It has been proved that this small integrated circuit can perform the task at hand while minimizing power consumption.
It is also very effective to provide appropriate design tools during the implementation of this project.
The project can also be enhanced by introducing other circuits, such as detecting dust on solar panels or external overvoltages. -
The driving switch locks the LED output.
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