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You can't draw lines on the Keep-out layer, for some reason? Can anyone draw it?

1450 0 Jun 13.2019, 09:46:17

AD18.1.6 version, PCB diagram, can not draw lines on the Keep-out layer, I do not know why? Can anyone draw it? As soon as you draw a line, jump to the Drill Drawing layer. And oddly enough, even if you draw a line from another layer, double-clicking cannot change to the Keep-out layer (there is no upper layer in the layer selection at all).

Shouldn't the antenna be perpendicular to the PCB board?(pcb project)

1513 0 Jun 13.2019, 09:38:46

This is an inductive antenna, and if the monopole antenna is not perpendicular to the ground, and, ah, should this kind of antenna be covered with a copper network near the pin? Is the shape of the earth circular, and if so, is its radius the same as the length of the spring antenna or at 1 to 4 wavelengths of the antenna?

Problem：low Voltage Power off Protection Circuit can not realize High Voltage recovery output

1503 0 Jun 13.2019, 09:35:31

A low voltage automatic power off circuit is designed. When the voltage is lower than 9V, the output is turned off and the output is restored when the voltage is higher than 9V. Software simulation function is normal, in the actual test, when the voltage from low to high slowly change, just reached the critical voltage, MOS can not be fully turned on, VGS only-4V, G-level voltage is not pulled to 0V, VDS has-5V, to adjust the voltage to 12V or so, MOS tube to achieve switching function, output power supply is normal. In this way, the function of automatic recovery of output can not be realized at all.

Would you please take a look at the PCB design of this PCB?

1316 0 May 29.2019, 09:23:19

What is wrong with this less than 10mil hole？-PCB design question

1448 0 May 29.2019, 09:21:38

This is a problem when I was working on an PCB because this is my first time in this field, I still have a little bit of no understanding of the PCB design, I do not understand.Anything was wrong?

How to solve this issue "Failed to Match All shapes" appears in PCB to gerber file-Altium design

1875 0 May 29.2019, 09:15:12

Gerber file appears this phenomenon Failed to Match All shapes, how to solve, thanks a lot

The performance of the circuit is unstable, and what are the reasons for it?-pcb question

1303 0 May 16.2019, 09:10:05

The newly designed trigger in the laboratory has two modes of internal and external trigger. The internal trigger is the trigger signal generated by the computer sending instructions through the serial port, and the external trigger is the trigger signal generated by the external trigger pulse. These two methods are normal when tested separately. After the trigger has been working normally for a period of time after being connected to the laboratory system, the trigger does not trigger the signal output (tested in internal trigger mode).

Please take a look at an op amplifier circuit. I don't know if it works.

1204 0 May 16.2019, 09:08:34

See this is my amplifier circuit.What is the frequency of the signal source? what is the capacity of C1 and C2?

How to test the PCB board of DDR3?

1218 0 May 16.2019, 09:05:26

Do you use an oscilloscope to measure the timing of the signal? Or is it measured in some other way? Do you have a better test document?

What is a plating?voids? How to avoid it?

1975 0 Apr 23.2019, 09:32:54

The state of hole breaking is a phenomenon of point distribution rather than whole circle opening, which is called point hole breaking, and some people call it "plating?voids". The common causes come from the poor treatment of the rubber slag process. The circuit board degumming slag process will first carry out the expansion agent treatment, and then carry on the strong oxidant "permanganate" erosion operation, this process will remove the glue slag and produce the micropore structure. After the removal process of the residual oxidant, rely on reductant removal, the typical formula is treated with acidic liquid. Because after the rubber residue treatment, there will no longer see the problem of residual rubber residue, operators often ignore the monitoring of the reduction acid, which may leave the oxidant on the pore wall. Then the circuit board enters the chemical copper process, a...

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