Introduction to Urban Street Light Automatic Monitoring System Hua Jianping (China Architecture Southwest Design Institute Shenzhen Institute Shenzhen 518049) Abstract Computer lighting technology and network communication technology are used to realize street lighting monitoring automation.
The street light monitoring system consists of a monitoring center and several sub-control points. The monitoring center is the center of operation, maintenance, processing, statistics, analysis and supervision of the entire street lamp monitoring system, and it is responsible for interconnecting with other management networks. The sub-control point is responsible for the power supply and control of the street light. The communication mode between the monitoring center and the sub-control point adopts CDPD wireless public data communication. Install a DDN line in the monitoring center, communicate with the terminal data communication transmitter through the interface converter and router, and complete telemetry, remote signaling and remote control. When an alarm occurs, the person on duty is called by MO DEM to handle the fault in time. A wireless data communication MODEM is configured on the standard serial port of each collector of each sub-control point for data exchange with the center.
The CDPD wireless communication method is the latest wireless data network launched by China Telecom. The network uses the standard TCP/IP protocol, so it can be easily developed on the basis of it. Compared with the traditional telephone line monitoring method, the connection speed of the CDPD is very fast, only a few milliseconds, and the MODEM dialing mode of the telephone line is used to connect, usually it takes 10 s to connect. It is precisely because of the fast connectivity of CDPD that the system can achieve real-time monitoring.
1 Monitoring system function 1.1 Remote control (1) The monitoring center automatically sets the group control switch command according to the switch light time curve or the program setting switch light time.
(2) The operator operates in the monitoring center to realize group control switch lights, or partial group control switch lights, or single point switch lights.
(3) The sub-control point independently switches the lights according to the preset time.
(4) The monitoring center periodically issues a clock calibration command to the sub-control point, and the sub-control point automatically switches the lamp according to the corrected time.
1.2 Remote monitoring or random detection of sub-control point street light parameters, power supply parameters: (1) power distribution control cabinet incoming line voltage.
(2) Three-phase current of each circuit.
(3) Energy metering.
(4) Transformer temperature, ambient temperature and humidity of the power distribution room.
1. 3 remote communication is reported by the sub-control point device to the monitoring center to report the working status and fault information, and can actively alarm when there is a fault. The system remote signal is as follows: (1) Switch status of each loop.
(2) Sub-control point various fault information: 1 power distribution control cabinet power-down information, switch alarm information 2 access control information, power distribution room infrared alarm information 3 smoke alarm information, ambient temperature and transformer temperature alarm information 4 power distribution room water Immersion alarm information 5 wireless data network failure information 6 current or voltage super upper and lower limit alarm information.
1.4 Alarm Management (1) Alarm Level 1 Emergency Alarm: Has been or will endanger equipment and communication security 2 General alarm: Alarms that may seriously affect equipment and communication security, need to be processed as soon as possible. 3 Pre-alarm: May affect equipment and communication security, Need to arrange for processing alarms.
(2) Alarm function requirement 1 Automatically reveal the alarm display and print the alarm information regardless of the monitoring system. All alarms use sound and light alarm signals. 2 Level 3 alarm signals use three different display colors and alarm sounds. 3 Alarm confirmation Function: After the alarm occurs, the operator can press the confirmation button on any screen to turn off the alarm sound, but the light flashes without turning off. After the fault is removed, the alarm light is turned off and the original state is restored. 4 When the emergency alarm occurs, the automatic dialing is performed through the telephone network (BB) Machine or telephone, mobile phone), send alarm information to relevant personnel. The alarm has a language prompt, telling the relevant personnel the name of the alarm, the location, time, level, etc. after the fault is removed, automatically cancel the sound and light alarm, and automatically dial the number through the telephone network to issue an alarm release message to the relevant personnel.
1.5 Data storage, report statistics and printing functions (1) The system automatically records alarm history and general historical data.
(2) Fault statistics report.
(3) Operational statistical reports (such as switching lamp time recording, etc.).
(4) Statistical data of monitoring data (voltage, current, electricity, etc.).
(5) Lighting rate report.
(6) Other customized reports according to the actual needs of the user.
1.6 Management Functions (1) System Configuration Function: When the operator changes or increases or decreases the deleted objects in the system and adjusts the system parameters, the user can complete the system configuration by changing the system configuration file.
(2) Security management: implement multi-level operation password and automatic password protection to ensure the security of remote control operation of the sub-control point.
(3) Network Control: Perform network settings to manage local workstations or remote workstations (computers or laptops). The workstation passes through the local area network, and the remote workstation accesses the monitoring system through telephone dialing and browses the monitoring data.
The 1.7 maintenance swipe function refers to the smart swipe system in the monitoring system. The maintenance personnel need to insert (or brush) the identification smart card on the on-site credit card device, and after the monitoring center confirms, the maintenance personnel are allowed to enter the site. In the monitoring center, you can check the maintenance personnel and maintenance records on the site. Adding this function is beneficial to standardizing the maintenance and management mechanism of street lamps.
2 The composition of the monitoring system (1) The monitoring center is composed of monitoring host, communication server, network workstation, hub, router, printer, multi-user card, cabinet and other equipment. Install a large-screen analog screen in the monitoring center, and you can see the running status of all the sub-control points at any time on the simulated screen map. The communication server is responsible for collecting the data information of each sub-control point, and collating and forming a database file for the main monitoring station and the ordinary workstation to call. The monitoring host acts as a user-oriented window for the entire system, and shoulders the burden of arranging, analyzing, and presenting a large amount of collected data to the user in a clear and clear manner. The composition of the monitoring center is shown in Figure 1.
(2) The sub-control point consists of data collector, uninterruptible power supply, CDPD wireless modem, three-phase AC voltage transmitter, three-phase AC current transmitter, pulse watt-hour meter, transformer temperature sensor, ambient temperature sensor, Water immersion sensor, door open sensor, infrared detector, smoke detector and other equipment. Through these devices, the status and parameters of each device in the field are fed back to the monitoring center, and the real-time monitoring of the monitoring center is received. The composition of the sub-control points is shown in Figure 2.
Installation June 2000
Metal Core PCB , MCPCB Manufacturing Service
Overview of Metal Core PCB
Metal Core PCB, The Printed Circuit Boards good thermal management solutions.
Metal core PCB (MCPCB), also known as heat sensitive PCB, insulated metal substrates (IMS PCB), Metal PCB, Metal Base PCB, Metal Backed PCB, Metal Clad PCB, etc., are designed to provide good thermal management, using metal substrates as circuit boards for radiator parts of circuit boards. These metal materials have high thermal conductivity. Aluminum is the most economical choice because it has good heat conduction and heat dissipation capacity and is cheaper than copper and steel. However, in order to adapt to different use scenarios, people choose different materials. Base metals in MCPCB are used as substitutes for FR4 or CEM3 boards. They radiate heat from key panel components to less important areas, such as metal radiator backings or metal cores. With the latest development of high power LED, the demand for MCPCB has exploded.
MCPCB is mostly single-sided IMS, metal core PCB manufacturer can also produce double-sided MCPCB, sometimes multi-layer IMS PCB and Metal Core PCB Prototype according to need. They have very advanced and perfect metal core PCB Manufacturing process. Whichever MCPCB is chosen, the heat dissipation capability should be taken into account when choosing the thickness of base material and copper. The thermal conductivity is expressed in W/mK. The value of standard aluminium sheet is 1.0 W/mK, but other options may be 2.0, 3.0 or even 5.0 W/mK.
Most MCPCB surface treatments use HASL LF. Without fine spacing elements and BGA, HASL LF may be the most suitable finish for power LED components. However, nothing prevents us from proposing all other surface treatments; OSP, ENIG, Chem Tin or Silver for IMS applications.
Metal Core PCB for LEDs
Thermal Management PCBs are necessary for high power LED applications due to the amount of heat that LEDs generate. The bare board is the real estate that sustains electronic components such as LEDs. PCBs containing a metal core dissipate heat in LED applications. Furthermore, the MCPCB provides a much lower thermal resistance for light emitting diode applications.
The LED on the metal core Printed Circuit Board (MCPCB) is designed to provide high power output in compact packaging. Each LED package contains an LED welded to MCPCB. These LEDs are very suitable for OEM or custom applications; therefore, they should not be used for home lighting.
Metal Core PCB Design Specifications
Metal Core PCB designers always focus on price and manufacturability. However, you can rest assured that we have experienced engineers who have been engaged in DFM inspection for many years, and provide you with suggestions for choosing the best materials.
Detailed Introduction of Metal Core PCB
Conventional PCB use FR4 epoxy glass-based material on both sides of a board. However, with the growing popularity of light-emitting diode or LED technology, metal core printed circuit board or MCPCB are being deployed to deal with the increased heat LEDs generate.
Today, metal core PCB are finding greater numbers of applications in the automobile industry, traffic light signal technology, in commercial buildings, shopping malls, and even inside homes.
MCPCB use either an aluminum or copper core with the bottom side of the board serving as the heat sink. MCPCB are also used to dissipate heat in intense power-generating analog circuitry.
Metal core PCB are connected through mounting holes and screws through a box build's chassis. In this arrangement, heat is not only dissipated through the metal core, but it is also transmitted to the chassis. Hence, an LED or analog device-populated board has a considerably larger surface finish for the purpose of dissipating that heat.
But here's a word of caution about using MCPCB – actually two things to be cautious about.
- One, you need to know that making an MCPCB is complex and complicated because a metal layer is laminated with FR4, a glass-base material. Therefore, the chemistry for lamination is different during board fabrication. There is a fair possibility that there would be voids underneath the lamination, if it is not bonded properly.
- Two, a fixture to dissipate the heat from the metal core needs to be carefully defined and designed. Both these concerns demand experience.
At JHYPCB, we've been doing this for a long time, as one of professional MCPCB/ Aluminum PCB manufacturers from ShenZhen, China. We can produce metal core PCB Prototype or aluminum PCB prototyping, aluminium PCB Board for led, No Quantity Requirements, and can successfully guide you through your next MCPCB project. We have worked with over half a dozen LED manufacturers over ten years and have seen enormous amounts of different applications using MCPCB.
Choose us to provide PCB manufacturing services for you. Contact us immediately.
How Do Metal Core Circuit Boards Differ From FR4 Boards?
The dielectric material`s thermal conductivity is measured in Watts per meter, Kelvin (W/mK.) A 2.0W rating is fairly common; such material is approximately 6x-7x as thermally conductive as FR4. Best practice is to keep the dielectric layer as thin as possible. Doing so creates the shortest possible path from the heat source to the metal backing plate which is many times more thermally conductive than the dielectric material. Most of the materials come in a very limited range of thicknesses anyway, usually between .003" and .006". You won`t have all that much opportunity to specify something thicker that could diminish the effectiveness of the material at performing its thermal transfer function.
The metal backing plate used on the bottom side is the thickest element in the structure. It is available in several different thicknesses but it is best to use one of the three most common (1.0mm, 1.5mm, and 3.2mm) because they are the easiest to purchase without delays. The metal layer adds rigidity, keeps the circuit flat, and adds enough thickness so that the MCPCB can use the same mounting hardware that would be used for any other standard thickness circuit board. The metal plate side of the board does not receive any surface finish or soldermask.
Metal Core PCB Vs. Fr4 PCB Comparison
- Conductivity: FR4 has low thermal conductivity, typically around 0.3W, while MCPCB has higher thermal conductivity, ranging from 1.0W-4.0W, most commonly around 2.0W.
- Plated Through Holes: FR4 PCB typically uses plated through holes. Through hole components possible if required. In MCPCB, plated through holes are not available for 1-layer PCB. All components are surface-mounted.
- Thermal Relief: Thermal relief in FR4 PCB typically involves vias for heat transfer. Longer drill cycle, adds many processes. MCPCB materials provide their own thermal relief. Via drilling, deposition, and plating processes are eliminated.
- Solder Mask: FR4 PCB solder mask is typically dark colors (green, red, blue, black.) Usually applied top and bottom. MCPCB solder mask are almost exclusively white for LED boards. Applied to top only.
- Thickness: FR4 PCB has a wide range of thicknesses available using various material combinations and layer counts. MCPCB thickness variation is limited by available backing plate thicknesses and dielectric sheet thicknesses.
- Machining Process: FR4 PCB uses standard machining practices (drilling, routing, v-scoring, countersink, counterbore) while MCPCB uses the same machining as FR4, except that v-score must use diamond coated saw blades for the added strain from cutting into metal.
Metal Core PCB Material
Metal Core PCB means the core (base) material for PCB is the metal, not the normal FR4/CEM1-3, etc. and currently the most common metal used for MCPCB manufacturer are Aluminum, Copper and steel alloy. Aluminum has good heat transferring and dissipation ability, but yet relatively cheaper; copper has even better performance but relatively more expensive, and steel can be divided into normal steel and stainless steel. It more rigid than both aluminum and copper, but thermal conductivity is lower than them too. People will choose their own base/core material according to their different application.
1. Aluminum PCB
Aluminum PCB , also, it is called Aluminium PCB, metal core PCB, MCPCB, IMS(Insulated metal substracte).
Aluminum PCB have 3 parts:
- Circuit Layer (Copper Layer)
- Dielectric Layer(Insulated Layer)
- Substrate Layer(Metal layer)
Aluminum Clad PCB
Available as 1 layer Non-Plated Through Hole (single sided), And 2+ layer Plated through Hole. Ideal application for LED lighting, power supply solutions. Aluminium Clad Benefits Include:
- Lower operating temperature.
- Reduce printed circuit board size.
- Increase power density.
- Extend the life of dies.
- Reduce the number of interconnects.
- Improve product thermal and mechanical performance.
- Combine power and control.
- Improve product durability.
- Enable better use of surface mount technology.
- Expedite heat sinks and other mounting hardware.
- Replace fragile ceramic substrates with greater mechanical durability
About Price:
- Price is based on the requirement of LED PCB
- PCB thickness: 0.6 – 3.0mm, always thickness more ,price higher
- Thermal conductivity: 1.0 – 10 W/m.k , thermal conductivity higher, price higher
- Material factory: Bergquist, Laird ETC, made in US factory that is more expensive than China.
2. Copper Core PCB
Copper core PCB is a copper substrate + Insulated layer + copper
Copper core PCB is a copper substrate + Insulated layer + copper circuits layer PCB, also, it is called copper substrate pcb, copper based pcb, copper clad pcb.
As a MCPCB manufacturer, we made various Copper core PCB for customers, Which used for High Power LED lighter ( 1000W+ ) and power supply.
In LED field, there are 4 types of Copper based Circuit Board.
COB Copper PCB(Chip on Board copper PCB)
Direct thermal path, no dielectric layer under the thermal path pad.
Direct thermal path, no dielectric layer,Aluminum-copper pcb.
3. Iron Based PCB
The iron-based PCB use material for the base is from special steel, silicon steel and ect in stand of FR4 or CEM1 and can dissipate heat away from critical board components and to less crucial areas such as metallic core or the metal heatsink backing.
China PCB manufacturers becomes more and more professional on Iron-Based PCB.
The Iron-based PCB has all the functions as metal materical and the following particular characteristics:
- Vacancy area convenient for further machinery , procuring and fixing of the base ;
- High mechanic strength, good forther machinery suitable for the assembly heaven electronic parts on its surface;
- Silicon-steel is iron magnetic, and can be applied on micro-motors such as on VTR, FDD.
Metal Core PCB Stack up and Thickness
Single Layer Metal Core PCB Stack Up
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It consists of a single copper conductive layer on top, a metal base plate (e.g. Aluminum) to provide rigidness to the circuit board and a thermal conductive dielectric working as the insulator. |
Double Sided Metal Core Stack Up
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It has two copper layers and the metal core is between the copper layers. Plated Through Holes (PTH) are used to interconnect the acopper layers so SMT and THT components can be placed on both sides. |
Multilayer Metal Core PCB Stack Up
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It has more than two conductive layers separated by thermal dielectric. In the bottom of the structure is the metal base. SMT components can only be placed on one side. Not THT components are allowed, but it provides the possibility to make blind and buried vias with internal signal layers and power/ground planes. |
MCPCB copper foil thickness can be 1 - 10 oz.
Benefits of Metal Core PCB Fabrication
Metal Core PCB Fabrication produces a product that transfers heat up to nine times more rapidly than a typical FR4 PCB. The laminates in MCPCB's dissipate heat which ensures that components which generate heat will remain cooler. This leads to a longer operating life as well as maximized performance for such components.
Applications of Metal Core PCB Fabrication
Although LED-based Solid State Light technologies have countless advantages, they inherently produce significant amounts of heat. This makes Metal Core PCB Fabrication helpful for applications like:
LED lights
High-current
LED, Spotlight, high-current PCB
Industrial power equipment
High-power
transistors, transistor arrays, push-pull or totem pole output circuit (to
tem pole), solid-state relay, pulse motor driver, the engine Computing
amplifiers (Operational amplifier for serro-motor), pole-changing device
(Inverter)
Cars
firing
implement, power regulator, exchange converters, power controllers, variable
optical system
Power
voltage
regulator series, switching regulator, DC-DC converters
Audio
input -
output amplifier, balanced amplifier, pre-shield amplifier, audio amplifier,
power amplifier
OA
Printer
driver, large electronic display substrate, thermal print head
Audio
input -
output amplifier, balanced amplifier, pre-shield amplifier, audio amplifier,
power amplifier
Others
Semiconductor
thermal insulation board, IC arrays, resistor arrays, Ics carrier chip, heat
sink, solar cell substrates, semiconductor refrigeration device
Other applications that are ideal for MCPCB integration are solar panels and motion control applications. We can also combine metal core with our HDI PCB technology. We also offer other advanced circuit technology including Flexible PCB Rigid PCB , and Rigid Flex PCB .
Additional information
Metal Core PCB manufacturing process
Metal Core PCB Manufacturing Capability
LED Lighting and MCPCB (Metal Core PCB)
Understanding the Importance of Metal Core PCBs
METAL CORE PCB VS STANDARD CIRCUIT BOARDS
Metal Core PCB is the best source for the heat transformation
Are Metal Core PCBs the Solution to Your Thermal Management Challenges?
Metal Core PCB
Printable Circuit Boards,Metal Core PCB,Metal Core Led PCB,Metal Core PCB Prototype
JingHongYi PCB (HK) Co., Limited , https://www.pcbjhy.com