The oscillation frequency of the multivibrator composed of IC1 (555) and R18, R19, C2 is f = 1.44 / (R18 + 2R19) C2, and the frequency corresponding to the illustrated parameter is about 2Hz. The output square wave signal is used as the shift clock pulse of IC2 and IC3.
IC2 and IC3 are 74LSl94 bidirectional shift registers, which are connected in series to form a shift register circuit. After starting, IC2 and IC3 are all cleared, Q0 ~ Q7 are all low level, the circuit is in the holding state, and the volume is minimum. When the metal sheet A is touched by hand, the S0 (pin ⑨) of IC2 and IC3 is high level, and IC2 and IC3 realize the serial right shift, so that LED0 to LED7 are sequentially lit, and at the same time, LED8 increases in brightness with the current stepwise As it increases, the resistance of the corresponding photoresistor Cds decreases and the volume gradually increases. The increase is controlled by the time of touching the A-chip. If you touch the metal sheet B with your hand, IC2 and IC3 realize serial left shift because S1 (⑩ foot) is high, and the corresponding control volume gradually becomes smaller. The reduction is controlled by the time of touching the B slice.
Under the action of the clock pulse signal, the control circuit can gradually increase or decrease the volume by touching the metal sheets A and B, thereby achieving multi-level control of the volume.
As shown in the figure is an eight-level touch volume control circuit. The controller consists of a multivibrator, a shift register, a touch control circuit, an impedance conversion circuit, etc.
Flex-Rigid PCB, it's the PCB that part of it is rigid and part of it is flex. It combine flex PCB and rigid PCB in a same PCB together and we call it flex-rigid PCB or rigid-flex PCB. Normally, the rigid PCB area is for soldering electronic components and the flex PCB area would be taken as cables to connect rigid PCB areas together, this could make the rigid-flex PCB perfectly suit for a wide range of applications.
PCB = printed circuit board and PCBA = printed circuit board assembly. For PCB, it means the copper circuits be printed on a board, and so the main composition of PCB are copper and board.
The copper is the circuits material and the circuits designed by the PCB designers. Depends on the current in the circuits, the PCB copper thickness could be done with 0.5oz-10oz. But the PCB designers need be noted that the copper track width/space need be enlarged with the thickness. For example, the minimum copper track width/space could be 3mil/3mil with 0.5oz, but would be 4mil/4mil with 1oz.
The PCB board could be rigid PCB, could be flex PCB and also could be flex-rigid PCB. And the materials could be FR4, PI, Aluminum, Copper-based, Rogers, Teflon, etc. They have different applications. For example, FR4 PCB is the most commonly used for rigid PCB and almost good for all electronics products; PI is the most commonly used for flex PCB; Aluminum and copper-based have good thermal diffusivity and always used for LED PCB ; Rogers PCB and Teflon PCB are always used for High Frequency PCB, etc.
We are the one-stop shop for all kinds of PCB manufacture service from PCB Prototype to big volume, which could save our customers a lot of time and money.
PCB Manufacture Capabilities
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Features |
Capabilities |
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Layers |
1-36 layers |
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Material |
FR-4, Aluminum, Copper, Polyimide, high frequency (Rogers, PTEE, PI), etc. |
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PCB Type |
FR-4 Standard PCB , Aluminum PCB , Copper-based PCB, HDI PCB , Rigid-Flex PCB, Flex PCB, Thick Copper PCB and Rogers PCB, etc. |
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Board Thickness |
0.1mm-6.0mm |
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Copper Thickness |
1/2oz-6oz(18um-210um) |
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Biggest Board size |
600mm*1200mm |
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Min Tracing/Spacing |
0.075mm/0.075mm (3mil/3mil) |
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Min drilling Hole diameter |
0.15mm(6mil), 0.1mm(4mil)-laser drill |
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Solder Mask |
Green, Black, White, Red, Yellow, Blue and Purple, etc. |
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Silkscreen color |
White, Blue, Black, Red, Yellow |
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Surface finish |
HASL Lead free, Immersion Gold (ENIG), Immersion Tin, Immersion Silver, OSP, Carbon oil, etc. |
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Special Techniques |
Impedance Control, Gold Fingers, Blind/Buried vias, Peelable solder mask, Half holes, Via-in-Pad and Countersink hole, etc. |
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Flex-Rigid PCB
Flex-Rigid PCB,Multilayer Rigid-Flex PCB,Rigid Flex PCB,Rigid Flex PCB Board
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