High voltage power supply board PCB secondary development

PCB Clone of High voltage power supply board

Input voltage: AC220V/380V±10%.

Output voltage: 0V～10KV

Output voltage: 0A～1A

Voltage regulation rate: Relative to load: 0.01% (no-load to rated load) Relative input: ±0.01% (input voltage change of ±10%)

Current regulation rate: Relative to load: 0.01% (no load to rated load) Relative to input: ±0.01% (input voltage change of ±10%)

Ripple voltage: 0.1% of maximum output voltage peak-to-peak at rated output voltage

Ambient temperature: 0 to +50°C at operation. -20°C to +80°C during storage.

Temperature coefficient: 0.01% per degree Celsius.

Remote control of output voltage and current: External potentiometers can be used to remotely control the output voltage and current using the power supply’s internal 10V reference voltage.

Remote voltage and current indication: 25-pin terminal block contains voltage and current indication signals from 0 to 10V, which can be externally connected to various digital or pointer meters.

Handheld radar tachograph circuit board copy

Handheld radar tachograph PCB copy

Radar velocimetry is a device that uses radio echoes in order to detect the direction and distance of a target. When the target approaches the radar antenna, the reflected signal frequency will be higher than the transmitter frequency; conversely, when the target goes away from the antenna, the reflected signal frequency will be lower than the transmitter rate. In this way, the relative speed of the target and the radar can be calculated by the change of frequency value.

Technical parameters

Speed range: 5-250: miles / hour 8-400 km / hour

Accuracy: +/- 0.1 mph

Target speed acquisition time: 0.046 seconds (ball) 0.08 seconds (car)

Refresh rate: 25 times/sec

Measurement distance:

4000 feet – passenger car

1500 feet – motorcycle sled

1000 feet – boats

200ft–baseball

Operating frequency: 24.150GHz

Power output: 15 milliwatts

CPU model: 56002DSP

Operating temperature: -28℃–48℃

Storage temperature: -40℃–60℃

With battery handle: 7.5V DC 1.5A current

With cable handle: 9-16V DC

Dimension: 23.5cm (H) × 9cm (W) × 26cm (L)

Shell material: high-strength polycarbonate plastic

Medical device MRI copy board

Magnetic resonance PCB secondary development for medical devices

Medical device MRI Control PCB Copy

Imaging Principle

A medical magnetic resonance imaging system (MRI) consists of a magnet, a coil, a control unit, a computer imaging system and a diagnostic bed. MRI is a biomagnetic nuclear spin imaging technology that has been rapidly developed with the development of computer technology, electronic circuit technology, and superconductor technology. It uses magnetic field and radio frequency pulses to make the hydrogen nucleus (H+) in human tissue in spin motion vibrate to produce radio frequency signals, which are imaged by computer processing. That is, there is a stable magnetic field and an alternating electromagnetic field acting on the sample. After removing the electromagnetic field, the nucleus in the excited state can jump to a lower energy level and radiate electromagnetic waves, and at the same time, a voltage signal can be induced in the coil, which becomes the nuclear magnetic resonance signal. Human tissues contain a large number of hydrogen nuclei due to the presence of large amounts of water and hydrocarbons, and the signals obtained with hydrogen nuclei are generally more than 1000 times larger than other nuclei. The water in human body organs and tissues is not the same, and the pathological process of many diseases will lead to the change of water morphology, which makes the voltage signal of normal tissues different from that of diseased tissues. Combined with the electronic computed tomography (CT) technology, we can get the image of any section of human tissues, especially for the diagnosis of soft tissue lesions, which shows its advantages, the lesion area is very sensitive and the image is clear. If the number of frequency variables of MRI is increased to two or more, two-dimensional or multi-dimensional MRI can be achieved, thus obtaining more information than one-dimensional MRI.

Magnetic field intensity meter: The resolving power is 0.1mT, and the maximum allowable error is not more than one-third of the object to be examined.

The test was performed according to the method recommended by AAPM and the method in the module manual. The performance parameters tested were signal-to-noise ratio, uniformity, linearity error (aberration), layer thickness error, spatial resolving power and low contrast resolving power. Firstly, the performance parameters were grouped according to the field strength, and the relationship between the performance parameters and the field strength was studied. Then, the uniformity, linearity error (aberration), layer thickness error, spatial resolution and low contrast resolution were grouped according to their sizes, and the distribution characteristics of the performance parameters were studied.

3.2.1 Signal-to-noise ratio

All the equipment is divided into 4 groups according to the field strength, the first group field strength <0.5T, for low field strength; the second group field strength of 0.5T ~ 0.9T; the third group field strength of 1.0T ~ 1.5T; the fourth group field strength ≥ 1.5T. Table 2 shows the maximum value, minimum value, extreme difference and average value of signal-to-noise ratio under 4 groups field strength. The average value of S/N ratio varies greatly from group to group, and increases obviously with the increase of field strength.

3.2.2 Uniformity

Uniformity is grouped by field strength, and there is no significant difference in uniformity among groups, see Table 3.

Equipment if grouped by uniformity, the number and percentage of units in each group is shown in Table 4. 97.5% or more of the equipment uniformity in more than 94%, 100% of the equipment uniformity in more than 90%.

3.2.3 Linearity error (aberration)

X-direction linearity error (aberration) grouped by field strength, the average value of X-direction linearity error of each group does not differ significantly, see Table 5.

Equipment if the X-direction linearity error (aberration) grouping, the number and percentage of each group as shown in Table 6. 97.5% or more of the equipment X-direction linearity error (aberration) in less than 5%, 2.5% of the equipment X-direction linearity error (aberration) more than 5%.

Y-direction linearity error (aberration) by field strength grouping, the average value of the Y-direction linearity error of each group is not significantly different, see Table 7. if the linearity error by Y-direction grouping, the number of units in each group and the percentage of Table 8. 97.5% or more of the equipment Y-direction linearity error (aberration) in 1.5% or less, 100% of the equipment Y-direction linearity error (aberration) in 3.5% or less.

3.2.4 Layer thickness error

The layer thickness of 8 devices could not be measured because the signal of some devices’ slant line image was too weak and some devices had no Profile function. For the 32 devices that have measured the layer thickness grouped by field strength, there is no significant difference in the layer thickness error of each group, see Table 9.

If grouped by the size of the layer thickness error, the number of units in each group and the percentage of Table 10. 90% of the equipment layer thickness error is less than 1.0mm, 10% of the equipment layer thickness error is more than 1mm.

3.2.5 Spatial resolution

Because the highest spatial resolution of the device is equal to the size of the pixel, in the measurement of spatial resolution FOV is taken as 256mm, pixel matrix is taken as 256×256, pixel is equal to 1mm, so the highest spatial resolution of the device is equal to 1mm. according to the results of field strength grouping, there is no significant difference in the spatial resolution of each group, see Table 11.

Among the 40 devices, 80% of the devices with spatial resolution of 1mm and 20% of the devices with spatial resolution of 1.25mm.

3.2.6 Low-contrast resolving power

According to the field strength grouping, the low contrast resolution is related to the field strength, as shown in Table 12. the devices with the field strength equal to and higher than 0.5T can distinguish the hole of Φ4mm/0.5mm deep, among the devices with the field strength lower than 0.5T, the devices with the low contrast resolution of Φ4mm/0.5mm deep account for 83%, and the devices with Φ6mm/0.5mm deep account for 17%

4 Discussion

The criteria for MRI clinical application performance proposed in the AAPM 100 report are quality assurance standards that are applicable to all manufacturers and models of equipment. Based on the statistical analysis of the test results of 40 MRI devices of different manufacturers and different field strengths, the following evaluations of the relevant standards were made:

4.1 Signal-to-noise ratio with respect to field strength

The field strengths of the 40 MRI devices were divided into the following four groups: <0.5 T, 0.5 T to 0.9 T, 1.0 T to 1.5, and ≥1.5 T. The average signal-to-noise ratio of each group increased with field strength, and was 77, 112, 194, and 270, respectively. The AAPM report did not propose a standard for signal-to-noise ratio, and different standards must be adopted for different field strengths if a standard for signal-to-noise ratio is to be specified.

4.2 Uniformity is independent of field strength

Among the 40 MRI devices, 100% of the devices had a uniformity of 90% or more. the uniformity standard recommended by the AAPM report is 80%, which is too low from the results of the experimental tests. With the advancement of MRI technology and the improvement of equipment performance, this performance has generally improved.

4.3 Linearity errors (aberrations) are independent of field strength

The linearity error recommended by the AAPM report is 5%, and the results of the test show that this standard is appropriate.

4.4 Layer thickness error is independent of field strength

Among the 32 devices with measured layer thickness, 90% of the devices have layer thickness error less than 1.0mm, and 10% of the devices have layer thickness error more than 1.0mm. The standard of layer thickness error introduced by the AAPM report is ±1mm, and the standard is also appropriate from the test results.

4.5 Spatial resolution is independent of field strength

The spatial resolution standard introduced by the AAPM report is 1mm, which is the ideal spatial resolution, from the test results only 79.4% of the equipment can reach this standard, there are still 20.6% of the equipment can not reach. The standard as a quality assurance standard is okay, but as the standard of clinical application quality is too high, according to the standard, there will be part of the equipment clinical application quality failed.

4.6 Low-contrast resolving power related to field strength

This parameter is not included in the performance parameters of MRI equipment proposed in the AAPM report, but we believe that this parameter is indispensable. Because the low contrast resolution is different from the spatial resolution, the latter is the ability to distinguish the target under high contrast conditions, and the former is the ability to distinguish the target under low contrast conditions, both are performance parameters directly related to the quality of clinical diagnosis. The low-contrast resolution can be quantitatively detected by specially designed body model. From the results of experimental testing, the low-contrast resolution is related to the field strength, and the devices with the field strength equal to or higher than 0.5T can distinguish the holes of Φ4mm/0.5mm deep, and 83% of the devices with the field strength lower than 0.5T can distinguish the holes of Φ4mm/0.5mm deep, and 17% of the devices can distinguish the holes of Φ6mm/0.5mm deep. 0.5mm deep hole. Therefore, the low contrast resolution standard should be set according to the different field strength.

Our PCB copy board team has accumulated 17 years of technical experience in Shenzhen and has been involved in almost all electronic products PCB circuit boards, especially for various high-precision special circuit boards and various multi-layer PCB copy board experience for many years, and has a better understanding of the structure and alignment rules of complex PCB boards containing laser holes, blind holes and buried holes. Under the premise of the reverse R & D technology means to reverse analysis of the circuit board, the original product PCB files, bill of materials (BOM) files, schematic files and other technical documents and PCB screen printing production files for 1:1 restoration, and then use these technical documents and production files for PCB board, component welding, flying probe test, circuit board debugging, complete the original circuit board prototype board complete copy of the original circuit board prototype.

With the advanced scanning technology, the latest copy software and the most experienced senior technical team in China, we have been providing various single-layer, double-layer, multi-layer PCB board copy, various blind buried hole boards, laser blind hole boards, UHF boards, ceramic PCB copy boards, component density, long lines all over the microstrip lines, high frequency processing requirements and strict EMC control of the communication board copy services, customers only need to provide a complete set of sample boards or a complete set of sample boards. Customers only need to provide a complete set of prototypes or prototypes, Qingbao Technology promises to copy the board at once, change the board, debugging, copy the accuracy of the board to 1mil.

ATM machine main control PCB Clone

ATM machine main control board PCB Copy

PLC industrial control board Reverse engineering

PCB Reverse engineering of PLC industrial control board

Security Equipment PCB Clone

Security Equipment PCB Clone

CCTV Camera Control board clone

Server memory stick PCB copy

High frequency power supply board PCB copy

Cell phone board PCB copy

Cell phone PCB copy board, cell phone board with many functions and components, but the PCB space is small, cell phone board PCB copy board rewriting of the wiring design of the restoration to go to the highest. Usually need four to six layers of PCB board. High-power circuits include RF buffers and voltage-controlled oscillators (VCO). Make sure that the PCB board on the high power area at least a block of land, preferably without over-hole above, the more copper skin the better. Sensitive analog signals should be as far away as possible from high-speed digital signals and RF signals.2. Design partitioning can be broken down into physical and electrical partitioning.

Physical partitioning mainly involves component layout, orientation and shielding; electrical partitioning can continue to be broken down into partitions for power distribution, RF alignment, sensitive circuits and signals, and grounding.

Physical Partitioning

Component layout is the key to achieving a good RF design, and the most effective technique is to first fix the components located in the RF path and adjust their orientation to minimize the length of the RF path, keeping the inputs away from the outputs and separating high power circuits from low power circuits as far as possible.

The most efficient stacking method is to arrange the main ground plane (main ground) on the second layer under the surface layer and route the RF lines on the surface layer whenever possible. Minimizing the size of the vias in the RF path not only reduces path inductance, but also reduces false solder points on the main ground and reduces the chance of RF energy leakage to other areas within the laminate.

In physical space, linear circuits like multi-stage amplifiers are usually sufficient to isolate multiple RF zones from each other, but duplexers, mixers, and IF amplifiers/mixers always have multiple RF/IF signals interfering with each other, so this effect must be carefully minimized.

RF and IF alignment

RF and IF alignment should be crossed as far as possible, and as far as possible in between them separated by a piece of ground.

The correct RF path is very important to the performance of the entire PCB board, which is why component layout usually takes up most of the time in the design of cell phone PCBs.

On the cell phone PCB board design, you can usually put the low noise amplifier circuit on one side of the PCB board, and the high power amplifier on the other side, and eventually connect them to the RF side and the baseband processor side of the antenna on the same side through the duplexer. Some skill is needed to ensure that the straight-through holes do not transfer RF energy from one side of the board to the other side, and a common technique is to use blind holes on both sides. The adverse effects of straight-through holes can be minimized by arranging them in areas where both sides of the PCB are free from RF interference. Sometimes it is not possible to ensure sufficient isolation between multiple circuit blocks, in this case it is necessary to consider the use of metal shields to shield RF energy in the RF region, metal shields must be soldered to the ground, must be maintained at an appropriate distance from the components, and therefore need to take up valuable PCB board space. It is very important to ensure the integrity of the shield as much as possible, the digital signal lines into the metal shield should go as far as possible to the inner layer, and it is best to go to the line layer of the PCB is a layer below the ground layer.

RF signal lines can go from the metal shield at the bottom of the small gap and ground gap in the wiring layer, but the gap around as much as possible to lay some ground, different layers on the ground can be connected together through multiple vias.

Decoupling circuit

Many RF chips with integrated linear lines are very sensitive to power supply noise, and usually each chip requires up to four capacitors and an isolation inductor to ensure that all power supply noise is filtered out. An integrated circuit or amplifier often with an open-drain output, so a pull-up inductor is required to provide a high-impedance RF load and a low-impedance DC power supply, the same principle applies to the power supply at the end of this inductor to decouple.

Some chips require multiple power supplies to operate, so you may need two or three sets of capacitors and inductors to decouple them separately. Inductors are rarely placed in parallel, as this creates a null-core transformer and induces interference signals, so they should be at least as far apart as the height of one of the devices, or arranged at right angles to minimize their mutual inductance.

Electrical partitioning

Some parts of the phone use different operating voltages and control them with the help of software to extend the battery operating life. This means that the phone needs to run multiple power supplies, and this poses additional problems for isolation.

Power is usually brought in from a connector and immediately decoupled to filter out any noise from outside the board, then distributed after a set of switches or regulators.

The DC current of most circuits on a cell phone PCB is quite small, so the alignment width is usually not an issue, however, a separate high current line as wide as possible must be run for the power supply of the high power amplifier to minimize the transmission voltage drop.

To avoid too much current loss, multiple vias are required to pass current from one layer to another. In addition, if the power supply pins of the high power amplifier cannot be sufficiently decoupled at its end, then high power noise will radiate throughout the board and cause a variety of problems.

The grounding of high power amplifiers is quite critical and often requires a metal shield to be designed for them. In most cases, it is also critical to ensure that the RF output is kept away from the RF input. This also applies to amplifiers, buffers and filters in the best case scenario, they will be able to operate stably at any temperature and voltage conditions. In reality, they can become unstable and add noise and intermodulation signals to the RF signal. If the RF signal line has to be wound from the input of the filter back to the output, this can seriously damage the bandpass characteristics of the filter.

In order to get good isolation of the input and output, first a ground must be laid around the filter, and secondly a ground should be laid in the lower area of the filter and connected to the main ground surrounding the filter. It is also a good idea to place the signal lines that need to pass through the filter as far away from the filter pins as possible.

In addition, the entire board should be grounded very carefully in various places, otherwise a coupling channel will be introduced. Sometimes you can choose to go single-ended or balanced RF signal lines, the principles of cross-talk and EMC/EMI also apply here. Balanced RF signal lines can reduce noise and cross-talk if routed correctly, but their impedance is usually higher, and to maintain a reasonable line width to get a matching signal source, alignment and load impedance, the actual wiring may have some difficulties.

Laptop motherboard PCB copy

Our PCB copy board team has accumulated 17 years of technical experience in Shenzhen and has been involved in almost all electronic products PCB circuit boards, especially for a variety of high-precision special circuit boards and various multi-layer PCB copy board experience for many years, the understanding of complex PCB board structure and alignment rules containing laser holes, blind holes, buried holes more than others. Under the premise of the reverse R & D technology means to reverse analysis of the circuit board, the original product PCB files, bill of materials (BOM) files, schematic files and other technical documents and PCB screen printing production files for 1:1 restoration, and then use these technical documents and production files for PCB board, component welding, flying probe test, circuit board debugging, complete the original circuit board prototype board complete copy of the original circuit board prototype.

With the advanced scanning technology, the latest copy software and the most experienced senior technical team in China, we have been providing various single-layer, double-layer, multi-layer PCB board copy, various blind buried hole boards, laser blind hole boards, UHF boards, ceramic PCB copy boards, component density, long lines all over the microstrip lines, high frequency processing requirements and strict EMC control of the communication board copy services, customers only need to provide a complete set of sample boards or a complete set of sample boards. Customers only need to provide a complete set of prototypes or prototypes, Qingbao Technology promises to copy the board at once, change the board, debugging, copy the accuracy of the board to 1mil.