졸업작품 의뢰는 ▶LINk 로 와주세요
http://320volt.com/en/op-ampli-sicaklik-anahtari-fan-kontrol/
▲코드 안쓴것
▼검색 키워드들
OP_Amp_applications.pdf-------------------------------------------------------------------
53쪽
Chapter 4
Single-Supply Op Amp Design Techniques
The previous chapter assumed that all op amps were powered from dual or split supplies,
and this is not the case in today's world of portable, battery-powered equipment.
이전 쳅터는 가정했다. that 모든 OP Amp들은 전원공급된다. from 듀얼 or 개별
When op amps are powered from dual supplies (see Figure 4–1),
the supplies are normally equal in magnitude,
opposing in polarity, and the center tap of the supplies is connected
to ground.
Any input sources connected to ground
are automatically referenced to the center of the supply voltage,
so the output voltage is automatically referenced to ground.
When op amp가 전원공급됬을때 from 듀얼 서플라이들로부터
그 서플라이들은 보통 같다. in 크기면에서
반대로 in 극성면에서, and the 센터 탭 of the 서플라이들은 연결되있다.
to GND로.
어느 입력 소스들 연결되있는 to GND에
은 자동으로 참조된다. to the 센터에 of the 서플라이 전압의,
so the 출력전압은 자동으로 참조된다. to GND에.
Single-supply systems do not have the convenient ground reference
that dual-supply systems have,
thus biasing must be employed
to ensure that the output voltage swings between
the correct voltages.
싱글-공급 시스템들은 do not 갖고있지않다. the convenient group reference를
that 듀얼공급 시스템들이 갖고있는
따라서 바이어싱은 must be 이용되야만한다.
to 확인하기위해 that the 출력전압으
(Voltage Output Swings : 얼마나 근접하게 op-amp 출력이 driven되는가에 대한 수치이다. )
Input sources connected to ground
are actually connected to a supply rail in single-supply systems.
This is analogous to connecting a dual-supply input
to the minus power rail.
This requirement for biasing the op amp inputs to achieve the desired
output voltage swing complicates single-supply designs.
When the signal source is not referenced to ground (see Figure 4–2),
the voltage difference
between ground and the reference voltage is amplified along with the signal.
Unless the reference voltage was inserted as a bias voltage,
and such is not the case when the input signal is connected to ground,
the reference voltage must be stripped from the signal
so that the op amp can provide maximum dynamic range.
An input bias voltage is used to eliminate the reference voltage when it must not appear
in the output voltage (see Figure 4–3).
The voltage, VREF, is in both input circuits,
hence it is named a common-mode voltage.
Voltage feedback op amps reject common-mode
voltages because their input circuit is constructed with a differential amplifier (chosen because
it has natural common-mode voltage rejection capabilities).
(Reference Voltage가 반전, 비반전 입력에 모두 들어가서 상쇄되었다.)
(그래서 공식에서 Vref가 빠져있다.)
When signal sources are referenced to ground, single-supply op amp circuits exhibit a
large input common-mode voltage. Figure 4–4 shows a single-supply op amp circuit that
has its input voltage referenced to ground. The input voltage is not referenced to the midpoint
of the supplies like it would be in a split-supply application, rather it is referenced to
the lower power supply rail. This circuit does not operate when the input voltage is positive
because the output voltage would have to go to a negative voltage, hard to do with a positive
supply. It operates marginally with small negative input voltages because most op
amps do not function well when the inputs are connected to the supply rails.
The constant requirement to account for inputs connected to ground or different reference
voltages makes it difficult to design single-supply op amp circuits. Unless otherwise specified,
all op amp circuits discussed in this chapter are single-supply circuits. The singlesupply
may be wired with the negative or positive lead connected to ground, but as long
as the supply polarity is correct, the wiring does not affect circuit operation.
Use of a single-supply limits the polarity of the output voltage. When the supply voltage
VCC = 10 V, the output voltage is limited to the range 0 ≤ Vout ≤ 10. This limitation precludes
negative output voltages when the circuit has a positive supply voltage, but it does not
preclude negative input voltages when the circuit has a positive supply voltage. As long
as the voltage on the op amp input leads does not become negative, the circuit can handle
negative input voltages.
Beware of working with negative (positive) input voltages when the op amp is powered
from a positive (negative) supply because op amp inputs are highly susceptible to reverse
voltage breakdown. Also, insure that all possible start-up conditions do not reverse bias
the op amp inputs when the input and supply voltage are opposite polarity.
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75쪽
Chapter 5
Feedback and Stability Theory
======================================================================================
http://www.instructables.com/answers/whats-the-difference-between-12V-and-GND/
▲마이너스 전압과 GND의 차이점에 대한 질문
what's the difference between -12V and GND?
Re-design의 댓글
In some circuits negative is the same as ground,
but in some circuits ground = 0 volts
and in other parts of the circuit
there is a negative voltage that is below ground.
몇몇 회로들에서 네거티브는 같다. as GND로,
but in 몇몇 회로들에선 GND=0V이다.
and in 다른 부품들에서 of the 회로의
there is a 네거티브 전압이 있다. that is 내려가는 GND아래로.
If you connect a voltmeter between ground (0 volts) and -12 volts
it will read a difference of 12 volts, with the ground being most positive.
만약 네가 연결하면 a 테스터기를 between GND 와 -12V 사이에
이건 읽어들일것이다. a 차이를 of 12V의, with GND는 most positive가 되며.
Electrical parts work because of a difference in potiential.
Many don't care which way the difference is (light bulb)
and some work in reverse (dc motor)
and some won't work at all or are destroyed.
전자 부품들은 동작한다. because of a 전위차 때문에.
많은것들은 신경쓰지않는다. which 방법이 the difference 인지(전등)
and 몇몇은 동작한다. in 역으로 (예컨데 DC모터)
and 몇몇은 동작하지않을것이다. 전혀 or 파괴될것이다.
IT's a hard concept to explain and goes much more into detail
than what I have just explained
but google "negative voltage" if you wish to learn more.
IT는 어려운 개념이다. to 설명하는데 and 접근한다. much more into 자세히
than 뭘 내가 이미 just설명했는지
but 검색한다. "네거티브 전압"을 if 네가 좀더 배우길 원하면.
https://www.elcircuit.com/2016/09/headphone-amplifier-circuit-using-tl074.html
4 채널 증폭기를 이용한 HeadSet 설계
TL074CN 사용 (MCP6004로 대체가능)
