A simple FM microphone

The circuit (see figure) uses a capacitive feedback oscillator, whose frequency is stable and adjustable. Its feedback signal is in the form of capacitor partial pressure, and the output signal of the oscillating tube is fed back to the input terminal. Among them, Re is a DC negative feedback resistor, C3 is a DC blocking coupling capacitor, and Ce is an emitter bypass capacitor. L, C1, C2, C form a resonant circuit. Since C2 is equivalent to being connected between the base and the emitter of the transistor BG, it forms a feedback circuit divided by C1 and C2. The feedback signal is taken from the voltage on C2. The oscillation frequency of the circuit is f = 1 / 2Ï€, where C = C1C2 / C1 + C2.

Experimental comments <br> The FM microphone is simple and easy to make, and is more suitable for beginners to imitate. In open areas, the transmission distance of this circuit is 20 to 30 meters. Long-term operating frequency has a large deviation. There are many harmonic content of the signal, which will interfere with the adjacent frequency.
In the specific production, MIC is best not to lead out with flexible wires, but to solder it firmly on the circuit board. The inductance L can be formed by spinning off 5-7 turns on a Φ0.3mm round bar. After adjusting the turn pitch, fix it with high-frequency wax. When judging whether the circuit is oscillating, the following simple method can be used. Use a normal pointer multimeter AC2V block, any test pen is floating, and the other test pen touches the antenna. If the pointer is wobbled, it means that the circuit has started to vibrate, and you can do the span adjustment.

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0.8mm Female Pin Header

0.8mm ( 0.031") Female Header Connector
Category:Board To Board Connectors
Sub-Category:Pin Header Female
Type:0.8mm

0.8mm ( 0.031") Female Headers Overview
Whenever there is a need for fitting small-sized connectors in compact devices, the 0.8mm pitch female header, or sometimes referred to as header connector, is ideally suited for this application. Not only does this female header space-savvy, but it is also designed for vacuum pick and place that makes it suitable for high volume automated manufacturing.

Antenk offers these low profile, easy-install, SMT or THM miniature female connector plugs at high quality and affordable China-quoted price, for board-to-board connection, snuggly fitting the pins of a male header and acting as a receptacle.

Assembly and service is simple with either vertical (straight), elevated or at a right angle configuration/orientation, which can dissipate current of about 1.0 A or less in a tape and reel packaging. The filleted corners can also remove shadowing allowing optimization of LED output.

Also, the 0.8mm pitch female headers are made to work in Arduino boards, Arduino Pro and Arduino Mega with either single or double-row female headers, facilitating connections for programming and incorporation into other circuits. They have the perfect height for clearing the USB-B connector and great for stacking multiple shields.

Female header always called as [Header connector", Antenk provide widely range of header connector, from 2.54mm (.100″ inch) pitch to 0.8mm (0.031 inch) pitch. The number of pins (contacts) is from 2 to 40 pins per orw. There are three type: Straight (Dip Vertical), Right angle, SMT (surface mount).

If you can not find the items you interest from above items, welcome to contact us, and you will always get fully responsive from us.

Applications of 0.8mm Pitch Female Headers
Its small size is most suitable for PCB connections of small equipment and devices such as:
Arduino Boards
Architectural and sign lighting
Retail and display lighting
Fluorescent LED retrofit lighting
Cabinet or furniture lighting
Commercial / residential cove lighting
WiFi equipment
Gaming consoles,
Measurement instruments
Medical Diagnostic and Monitoring equipment
Communications: Telecoms and Datacoms
Industrial and Automotive Control and Test


Mount Type: Through-hole vs Surface Mount
At one side of this female header is a series of pins which can either be mounted and soldered directly onto the surface of the PCB (SMT) or placed into drilled holes on the PCB (THM).

Through-Hole (Poke-In)
Best used for high-reliability products that require stronger connections between layers.
Aerospace and military products are most likely to require this type of mounting as these products experience extreme accelerations, collisions, or high temperatures.
Useful in test and prototyping applications that sometimes require manual adjustments and replacements.
0.8mm vertical single row female header, 0.8mm vertical dual row female header, 0.8mm Elevated single row female header, 0.8mm Elevated dual row female Header, 0.8mm right-angle single row female header and 0.8mm right-angle dual row female header are some examples of Antenk products with through-hole mount type.

Surface-Mount
The most common electronic hardware requirements are SMT.
Essential in PCB design and manufacturing, having improved the quality and performance of PCBs overall.
Cost of processing and handling is reduced.
SMT components can be mounted on both side of the board.
Ability to fit a high number of small components on a PCB has allowed for much denser, higher performing, and smaller PCBs.
0.8mm Right-angle Dual Row female header, 0.8mm SMT Single row female header, 0.8mm SMT Dual row female header and 0.8mm Elevated Dual Row female Header are Antenk`s SMT female headers.

Soldering Temperature for 0.8mm Pitch Female Headers
Soldering SMT female connectors can be done at a maximum peak temperature of 260°C for maximum 60 seconds.

Orientation/Pin-Type: Vertical (Straight) and Right-Angle
0.8mm pitch female headers may be further classified into pin orientation as well, such as vertical or straight male header or right-angle female header.

Vertical or Straight Female Header Orientation

One side of the series of pins is connected to PCB board in which the pins can be at a right-angle to the PCB surface (usually called "straight" or [vertical") or.

Right-Angle Female Header Orientation
Parallel to the board's surface (referred to as "right-angle" pins).
Each of these pin-types have different applications that fit with their specific configuration.

PCB Connector Stacking
Profile Above PCB
This type of configuration is the most common way of connecting board-to-board by a connector. First, the stacking height is calculated from one board to another and measured from the printed circuit board face to its highest insulator point above the PCB.

Elevated Sockets/Female Headers
Elevated Sockets aka Stacked sockets/receptacles or Mezzanine are simply stacked female headers providing an exact distance requirement between PCBs that optimizes electrical reliability and performance between PCB boards.

Choosing this type of stacking configuration promotes the following benefits:
Connector Isolation - the contacts are shrouded preventing cable connection mishaps and good guidance for the mating header connectors.
For off-the-shelf wireless PCB module, stacking height is optimized with elevated sockets.
Offers superior strength and rigidity.
Polarisation prevents users from inverted insertion.

Single, Dual or Multiple Number of Rows
For a 1.0mm straight or vertical female header, the standard number of rows that Antenk offers ranges from 1 to 2 rows. However, customization can be available if 3 ,4 or n number of rows is needed by the customer. Also, the number of contacts for the single row is about 2-40 pins while for dual row, the number contacts may vary from 2-80 pins.

Pin Material
The pins of the connector attached to the board have been designed with copper alloy. With customer`s demand the pins can be made gold plated.

Custom 1.0mm Pitch Female Headers
Customizable 1.0 mm pitch female headers are also available, making your manufacturing process way faster as the pins are already inserted in the headers, insulator height is made at the right size and the accurate pin length you require is followed.
Parts are made using semi-automated manufacturing processes that ensure both precision and delicacy in handling the headers before packaging on tape and reel.

Tape and Reel Packaging for SMT Components
Antenk's SMT headers are offered with customizable mating pin lengths, in which each series has multiple number of of circuits, summing up to a thousand individual part number combinations per connector series.

The tape and reel carrier strip ensures that the headers are packaged within accurately sized cavities for its height, width and depth, securing the headers from the environment and maintaining consistent position during transportation.

Antenk also offer a range of custom Tape and reel carrier strip packaging cavities.

Female Header Connector,0.8Mm Female Pin Header,0.8Mm Female Header,0.8Mm Pcb Header, Pitch 0.8mm Board to Board Connectors

ShenZhen Antenk Electronics Co,Ltd , https://www.antenksocket.com

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