FEMTO SMA ZONE

24/06/2022

Current Era
EV
Femto is in EV Charging Station and Battery Swapping
Launch is nearing....Stay with us for future updates

31/12/2017

HAPPY NEW YEAR 2018

28/10/2017

EMBEDDED SYSTEMS

A Short Description......

Embedded Systems is widely used in all kind of Platforms.From smaller things to larger.

What is Embedded Systems ?

The Relation between the Hardware and Software which was Created by You is Embedded System.

03/05/2017

HOW TO USE A MULTIMETER

09/03/2017

78XX Voltage Regulators

The 78XX family of voltage regulators is extremely popular. These devices are known as three terminal regulators, as they come in packages with just three pins. Pin 1 is for the input voltage, pin 2 is for the output voltage, and pin 3 is for ground. There are three devices: the 7805 for a +5 volts output, the 7812 for a +12 volts output, and the 7815 for a +15 volts output. The minimum input voltage should be two volts more than the rated output voltage, and can vary up to +35 volts. The 78XX series can provide a stable, constant output voltage over that range of input voltages with up to one ampere of output current. If the circuit should suddenly demand more than one amp of current (as might be the case with a short circuit), the 78XX regulators include on-chip protection circuitry that will shut down the regulator before it can be destroyed by overheating.

07/03/2017

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship

I = V / R ,

where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.

The law was named after the German physicist Georg Simon Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. He presented a slightly more complex equation than the one above (see History section below) to explain his experimental results. The above equation is the modern form of Ohm's law.

Circuit Analysis,

Where V=IR,

Where R=V/I

See the magical Triangle to implement for your analysis

21/01/2017

Continuation of PCB process from the previous post....................

Subtractive, additive and semi-additive processes

Subtractive methods remove copper from an entirely copper-coated board to leave only the desired copper pattern. In additive methods the pattern is electroplated onto a bare substrate using a complex process. The advantage of the additive method is that less material is needed and less waste is produced. In the full additive process the bare laminate is covered with a photosensitive film which is imaged (exposed to light through a mask and then developed which removes the unexposed film). The exposed areas are sensitized in a chemical bath, usually containing palladium and similar to that used for through hole plating which makes the exposed area capable of bonding metal ions. The laminate is then plated with copper in the sensitized areas. When the mask is stripped, the PCB is finished.

Semi-additive is the most common process: The unpatterned board has a thin layer of copper already on it. A reverse mask is then applied. (Unlike a subtractive process mask, this mask exposes those parts of the substrate that will eventually become the traces.) Additional copper is then plated onto the board in the unmasked areas; copper may be plated to any desired weight. Tin-lead or other surface platings are then applied. The mask is stripped away and a brief etching step removes the now-exposed bare original copper laminate from the board, isolating the individual traces. Some single-sided boards which have plated-through holes are made in this way. General Electric made consumer radio sets in the late 1960s using additive boards.

The (semi-)additive process is commonly used for multi-layer boards as it facilitates the plating-through of the holes to produce conductive vias in the circuit board.

17/01/2017

Continuation of PCB process from the previous post

Panelization

Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing panels. The assemblers often mount components on panels rather than single PCBs because this is efficient. The bare board manufactures always uses panels, not only for efficiency, but because of the requirements of the plating process. Thus a manufacturing panel can consist of a grouping of individual PCBs or of arrays, depending on what must be delivered.

The panel is eventually broken apart into individual PCBs; this is called depaneling. Separating the individual PCBs is frequently aided by drilling or routing perforations along the boundaries of the individual circuits, much like a sheet of postage stamps. Another method, which takes less space, is to cut V-shaped grooves across the full dimension of the panel. The individual PCBs can then be broken apart along this line of weakness. Today depaneling is often done by lasers which cut the board with no contact. Laser panelization reduces stress on the fragile circuits.

Copper patterning

The first step is to replicate the pattern in the fabricator's CAM system on a protective mask on the copper foil PCB layers. Subsequent etching removes the unwanted copper. (Alternatively, a conductive ink can be ink-jetted on a blank (non-conductive) board. This technique is also used in the manufacture of hybrid circuits.)

1) Silk screen printing uses etch-resistant inks to create the protective mask.

2) Photoengraving uses a photomask and developer to selectively remove a UV-sensitive photoresist coating and thus create a photoresist mask. Direct imaging techniques are sometimes used for high-resolution requirements. Experiments were made with thermal resist.

3) PCB milling uses a two or three-axis mechanical milling system to mill away the copper foil from the substrate. A PCB milling machine (referred to as a 'PCB Prototyper') operates in a similar way to a plotter, receiving commands from the host software that control the position of the milling head in the x, y, and (if relevant) z axis.

4) Laser resist ablation Spray black paint onto copper clad laminate, place into CNC laser plotter. The laser raster-scans the PCB and ablates (vaporizes) the paint where no resist is wanted. (Note: laser copper ablation is rarely used and is considered experimental.[clarification needed])

The method chosen depends on the number of boards to be produced and the required resolution.

Large volume

Silk screen printing – Used for PCBs with bigger features
Photoengraving – Used when finer features are required

Small volume

Print onto transparent film and use as photo mask along with photo-sensitized boards (i.e., pre-sensitized boards), then etch. (Alternatively, use a film photoplotter)
Laser resist ablation
PCB milling

Hobbyist

Laser-printed resist: Laser-print onto toner transfer paper, heat-transfer with an iron or modified laminator onto bare laminate, soak in water bath, touch up with a marker, then etch.
Vinyl film and resist, non-washable marker, some other methods. Labor-intensive, only suitable for single boards.

to be continued...............

We will update further later

11/01/2017

11/01/2017

PCB MANUFACTURING

PCB manufacturing consists of many steps.

PCB CAM

Manufacturing starts from the PCB fabrication data generated by computer aided design, such as Ge**er layer images, Ge**er or Excellon drill files, IPC-D-356 netlist and component information.

The Ge**er or Excellon files in the fabrication data are never used directly on the manufacturing equipment but always read into the CAM (Computer Aided Manufacturing) software. CAM performs the following functions:

1) Input of the fabrication data.
2) Verification of the data; optionally DFM
3) Compensation for deviations in the manufacturing processes (e.g. scaling to compensate for distortions during lamination)
4)Panelization
5)Output of the digital tools (copper patterns, solder resist image, legend image, drill files, automated optical inspection data, electrical test files,...)
to be continued...............

We will update further tomorrow

09/01/2017

PCB DESIGN

Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the finished photomask was photolithographically reproduced onto a photoresist coating on the blank copper-clad boards.[citation needed]

Modern PCBs are designed with dedicated layout software, generally in the following steps:

Schematic capture through an electronic design automation (EDA) tool.

Card dimensions and template are decided based on required circuitry and case of the PCB.

The positions of the components and heat sinks are determined.

Layer stack of the PCB is decided, with one to tens of layers depending on complexity. Ground and power planes are decided.

A power plane is the counterpart to a ground plane and behaves as an AC signal ground while providing DC power to the circuits mounted on the PCB.

Signal interconnections are traced on signal planes. Signal planes can be on the outer as well as inner layers.

For optimal EMI performance high frequency signals are routed in internal layers between power or ground planes.

Line impedance is determined using dielectric layer thickness, routing copper thickness and trace-width.

Trace separation is also taken into account in case of differential signals. Microstrip, stripline or dual stripline can be used to route signals.

Components are placed. Thermal considerations and geometry are taken into account. Vias and lands are marked.

Signal traces are routed. Electronic design automation tools usually create clearances and connections in power and ground planes automatically.

Ge**er files are generated for manufacturing.

03/01/2017

PRINTED CIRCUIT BOARD

A printed circuit board (PCB) mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. Components – capacitors, resistors or active devices – are generally soldered on the PCB. Advanced PCBs may contain components embedded in the substrate.

PCBs can be single sided (one copper layer), double sided (two copper layers) or multi-layer (outer and inner layers). Conductors on different layers are connected with vias. Multi-layer PCBs allow for much higher component density.

FR-4 glass epoxy is the primary insulating substrate. A basic building block of the PCB is an FR-4 panel with a thin layer of copper foil laminated to one or both sides. In multi-layer boards multiple layers of material are laminated together.

Printed circuit boards are used in all but the simplest electronic products. Alternatives to PCBs include wire wrap and point-to-point construction. PCBs require the additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Manufacturing circuits with PCBs is cheaper and faster than with other wiring methods as components are mounted and wired with one single part.

A minimal PCB with a single component used for easier modeling is called breakout board.[1]

When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly (PCBA). The IPC preferred term for assembled boards is circuit card assembly (CCA),[2] and for assembled backplanes it is backplane assemblies. The term PCB is used informally both for bare and assembled boards.