Active brilliant brace up cite a base: Date of active brilliant vibration shape is numerous, and the definition citing a base of model of avery kind of differs somewhat, receive a law to also differ, below small write the introduction active brilliant brace up bring crural identifying, with convenient everybody. Have a dot number for 1 foot, by anticlockwise (pin is down) it is respectively 2, 3, 4. Active brilliant brace up normally usage: One foot is impending, 2 feet ground connection, 3 feet receive output, 4 feet receive voltage. Active brilliant brace up the in-house oscillator that does not need DSP, signal quality is good, stabler, and join way is relatively simple (basically be to make wave of filter of good power supply, use network of wave of the PI that a capacitance and inductance form filter normally, the resistor that output end is worth with a small block filters signal can) , do not need complex configuration circuit. Opposite at passive crystal, active brilliant brace up blemish is his signal n is fixed, need has chosen appropriate output n, flexibility is poorer, and the price is high. Active brilliant brace up crystal comprises right quartz, chip can become quartz to be used for the oscillator, it is the piezoelectric effect that is based on it: Two in chip extremely on increase one electric field, can make crystal produces machinery to be out of shape; In quartz add on chip hand in change voltage, crystal can produce mechanical vibration, at the same time machinery is out of shape vibration can arise again hand in change electric field, although this kind is handed in,change the voltage of electric field is extremely faint, it is very stable that Dan Jizhen uses frequency. When adscititious hand in change the natural frequency of the frequency of voltage and chip (decide by the dimension of chip and appearance) equal when, the extent of mechanical vibration will increase quickly, this kind of phenomenon is called " the resonance that suppress report " . Of condition of the resonance that suppress report build and maintain must have the aid of comes true at oscillator circuit ability. Graph 3 it is a series connection oscillator, the two class amplifier that transistor T1 and T2 form, crystal XT and capacitance C2 form quartz LC circuit. In this circuit, crystal is equivalent to quartz an inductance, c2 is alterable capacitor, adjust its capacity can make circuit enters syntonic state. Voltage of this oscillator power supply is 5V, output weaveform is square wave. Active brilliant brace up with passive brilliant brace up go up in electronics, call the circuitry that contains transistor element normally " active circuit " (wait for) like filter of active sound box, active, and the circuit that allows component composition by block only calls " passive circuit " . The crystal oscillator in computer also is divided for passive brilliant brace up with active brilliant brace up two sort. Passive brilliant brace up with active brilliant brace up English name is different, passive brilliant brace up for Crystal(crystal) , and active brilliant brace up call Oscillator(oscillator) . Passive brilliant brace up it is what to cite a base 2 times do not have polarity component, need have the aid of generates oscillation signal at clock circuit ability, oneself cannot oscillation rises, so " passive brilliant brace up " this wording is not exact; Active brilliant brace up 4 cite a base only, it is a complete oscillator, among them besides quartz outside crystal, still have transistor and block look element, volume is accordingly larger. The frequency stability of crystal oscillator can amount to quartz 10^-9/ day, even 10^-11. For example the oscillator of 10MHz, frequency is more than commonly in a day of change in 0.
1Hz. Accordingly, can regard crystal oscillator as completely constant fiducial frequency the source (quartz is to use quartz in watch, electron watch crystal will do timing fiducial frequency) . Be born to from PC now, advocate board go up to use all the time 14.
Crystal oscillator regards the quartz of 318MHz as fiducial frequency source. Advocate board go up besides this 14.
The brilliant of 318MHz brace up, still can find a frequency for 32.
The brilliant of 768MHz brace up, it is used at real time clock (in RTC) circuit, show exact time and date. Quadrate active brilliant brace up bring a foot to distributing: 1, of square, use DIP-8 is enclosed, those who get ready is 1 foot. 1-NC; 4-GND; 5-Output; 8-VCC2, long square, use DIP-14 is enclosed, those who get ready is 1 foot. 1-NC; 7-GND; 8-Output; 14-VCCBTW: 1, power source has two kinds, one kind is TTL, can use 5V only, one kind is HC, can 3.
3V/5V2, edge has is pointed horn, 3 round horn, sharp-angled is one foot, and get ready consistent. Vcc OutNC(is nodded) GND active brilliant brace up for quadrilateral square or rectangular metal box, look at nominal at the same time (top) , left next empty feet, right go to the fields, left go up VCC(5V) , right go up output. Receive electrify source to be able to see weaveform with oscillograph. CNC Milling