Because the street lights are horizontally inserted, using LED manufacturing can only make one-sided lighting, but only need to adjust the position when the light bulb is installed, which will not affect the lighting effect. The power of the street light is 20W, 30W, 40W, 50W made of high-power LED, long service life and maintenance-free. As the LED consumes less power, has a lower voltage and a smaller current, the cross-section of the installation cable is reduced accordingly, saving installation costs.
A complete road lighting system consists of a light source, a cable, and a power supply system.
1. Comparison between LED street lamps and traditional street lamps Assuming that there are three sections of a city with a length of 3 km, 5 km, and 10 km, the street lights are laid every 30 meters and calculated on each side. The three sections of road need to be calculated. The total number of street lamps is 202 inches, 33 inches, and 66 inches respectively. The conventional street lamp is based on a high pressure sodium lamp with a power of 250W. The LED street lamp is based on a power of 50W.
The unit price of traditional street lamps is 1,000 yuan/inch, and the unit price of LED street lamps is 3,000 yuan/inch. The cost of light sources required for laying three kinds of roads with traditional street lights is: 202*100=20200 yuan, 333*1000=333,000 yuan, 666*1000 = 66,600 yuan, the cost of light source required for laying LED street lights of three lengths is: 202*300=606000, 33*300=99,900, 66*2 00=1998000
Second, LED street lamp and traditional street lamp cable cost comparison We have to analyze the length of the three-length road two kinds of light source laying cable costs, 3 km road traditional street light trunk cable load flow I = P/U = 202 * 250/220 = 230A, which requires a copper core cable with a cross-sectional area of ​​60mm2, and the unit price is 120 yuan/m, the cable cost is 120*3000=360,000 yuan, and the LED street light trunk cable load flow l=P/U=202*50 /220=44A, which requires a copper core cable with a cross-sectional area of ​​1Omm2. It requires a 12mm2 copper core cable with a unit price of 12 yuan/m2, a cable cost of 12*300=3.6 million yuan, and a 5km road traditional street lamp. Main line cable load flow I = P/U = 333 * 250/220 = 377A, it requires a cross-section of 90mm2 copper cable, the price is 180 yuan / m, the cable cost is 980 * 5000 = 900,000 yuan, LED street lamp Main trunk cable load flow rate I=P/U=333*50/220=73A, it needs a copper core cable with a cross section of 20mm2, the unit price is 25 yuan/bar cost is 25*5000=12.5 million yuan, 10 kilometers road tradition Street light trunk cable flow I=P/U=666*250/220=680A, which requires a cross-section 400m2 copper core cable, the unit price is 360 yuan / m, the cable cost is 360 * 10000 = 3.6 million yuan, LED street light main line cable load flow I = P / U = 666 * 50220 = 146A, it needs a cross-section of 42mm2 Copper core cable, the unit price is 60 yuan / m, the cost is 600,000 yuan.
4 Layer PCB
What is 4 layer PCB?
Four-layer circuit board is a kind of Printed Circuit Board. It is made of four layers of glass fibre, which can reduce the cost of PCB.
Compared with Double Sided PCB , multi-layer PCB have many advantages. They can be designed more compactly. They can greatly improve noise resistance and make layout easier.
There are also great differences between the 2-layer and 4-layer PCB. For details, please click: What's the difference between 2 layer and 4 layer PCBs?
4 layer PCB stackup and thickness
4 layer PCB stackup include two inner layers, inner layer 1 and 2, are sandwiched between the top and bottom layers. From top to bottom, the 4-layer PCB stackup like below ,The top, i.e. the signal layer (0.0014 in. width) is followed by a prepreg layer with a thickness of 0.0091 in. and dielectric constant of 4.2. The top layer is copper material. The prepreg layer is followed by inner layer 1 (0.0014 in.), referred to as the plane. A core sublayer is part of inner layer 1, which has a width of 0.037 in. This is followed by inner layer 2, which is another plane layer made with 1 oz. copper and is 0.0014 in. thick. Another prepreg sublayer constituting two sheets that are 0.0091 in. thick forms part of inner layer 2. The final layer, the bottom layer, is also 0.0014 in. thick, and is a signal layer as well. Interconnects are soldered and placed on the top and bottom layers.
4-layer PCB has two stacking forms
The standard 4-layer PCB stack is shown below, and GND and VCC can be switched according to the layer with more signals.
If you don't want to connect all the ground pins through the hole, there will be different stacks and wide power routing on the signal plane.
For the following reasons, this may be a better stack to use a four-layer PCB:
- The signal layer is adjacent to the plane. The signal running on the reference plane (whose voltage is exactly at the VCC) will still return on the reference plane.
- Signal layers are tightly coupled to their adjacent planes.
- The ground surface can be used as a shield for the internal signal layer. You will get better results, so that your plane height is as low as possible.
- Multiple grounding layers reduce the grounding (reference plane) impedance of PCB and common mode radiation.
When the high-speed signal changes the reference plane, there should be a nearby path for its return current to move between the two reference planes. Using two horizons, you can do this by connecting two planes directly to a single channel. For grounding and power layers, the connection must be made through capacitors, which usually require two through-holes and one capacitor. This means worse signal integrity and more circuit board occupancy. On the other hand, having a power plane can reduce the voltage drop on the power rail, thereby releasing the space on the signal layer.
PCB Board Thickness
4 LAYER 0.8 MM STANDARD BUILD
4 LAYER 1.6 MM STANDARD BUILD
0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm, 2.0mm, 2.4mm, Please contact us if your board exceeds these.
4 layer PCB Prototype
4-layer circuit board prototyping refers to the trial production of Printed Circuit Boards before mass production. It is mainly used for electronic engineers to design circuits and complete PCB Layout, then to carry out small-scale trial production process to the factory, that is, proofing PCB. The production quantity of four-ply proofing generally has no specific boundaries. Generally, engineers call it proofing before product design has not been confirmed and test has been completed.
Notices for proofing of four-layer circuit boards
The precautions for the production of four-layer PCB samples generally include two groups, one is the Engineer group, the other is the PCB Sample manufacturer.
As a group of engineers, the matters needing attention in proofing are as follows:
1. Choose proofing quantity carefully to control cost effectively.
2. Specially confirm device packaging to avoid proofing failure due to packaging errors.
3. Conduct comprehensive electrical inspection to improve the electrical performance of PCB board.
4. Make good signal integrity layout, reduce noise and improve PCB stability.
As a manufacturer of four-layer circuit boards, the precautions are as follows:
1. Check PCB files carefully to avoid data problems.
2. Conduct process approval in an all-round way and process configuration with self-manufacturer.
3. Control production quantity, reduce cost and maintain quality.
4. Communicate with customers who need samples to prevent accidents in advance.
4 layer PCB price and cost
We specialize in Quick Turn PCB services with an industry leading turnaround time as fast as 24 hours. Three low-cost options for a small number of PCB prototyping needs. At the same time, we also provided Flexible PCB , Rigid- Flex PCB , Metal Core PCB , High-TG PCB, Aluminum PCB , PCB Stencils, PCB Assembly Services and so on. Using the same high-tech equipment as our full-service PCB, it can be manufactured quickly and with virtually no limits.
Cost of four layer PCB is higher than double sided PCB because of complexity of design and higher sensitivity. The better quality of signals, achieved by reducing distortion and propagation levels, is also a factor. Because of the higher levels of signal integrity and reduced interference levels, more manufacturers prefer four layer PCB.
4 layer PCB Manufacturing
We provide a full range of PCB functions to meet all your PCB needs. At present, we accept five PCB file formats (gerber file,.Pcb,.Pcbdoc.cam or.brd file format) for PCB manufacturing. But if you design a circuit board using Sprint-Layout software, you can send the. LAy6 file to us to manually generate the Gerber file.
JingHongyi PCB can provide you with multi-layer PCB board that meets RoHS standard. With laminated material, it can match high temperature in assembly process. It is important to remember that some lead-free assembly processes will require laminated substrates to withstand temperatures exceeding 260 degrees Celsius or 500 degrees Fahrenheit over a longer period of time. To solve this problem, we have high temperature laminates in stock, so that our customers can meet the higher temperature cycle requirements of some lead-free assembly applications.
Min. Order Quantity: 1 pcs
Material: FR-4
Finished Copper: 1oz/2oz/3oz(35μm/70μm/105μm)
Inner Layer Copper Thickness:1oz/1.5oz(35μm/50μm)
Silkscreen: White, Black, None
Surface Finishing: HASL with lead, HASL lead free, Immersion gold, Hard Gold ,OSP...
Shape: Custom Shape
100% Quality control
When making circuit boards, and after they are finished, we will test and inspect them strictly to ensure that the product reaches 100% eligibility rate. Preferential prices and higher quality have always been our constant pursuit:
- E-test
- AOI - Testing (Automatic Optical Detection)
- X-ray (check multi-layer registration accuracy)
- CCD-camera controlled drilling
- Impedance control
Videos for 4 layer PCB design and manufacturing
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