wave generator
Introductions.
Sinusoidal wave is the most fundamental of all kinds of other waveforms. That's why when you learn the basics of alternating electrical current, an amplifier or oscillator is always inseparable from the sinusoidal wave. Although the sinusoidal wave is very important in the field of electronics, nonsinusoidal waves are also significant. Field study and nonsinusoidul sinusoidal wave (pulse crcuit) is very broad and therefore relatively limited in space, the writer tries to discuss the topics mentioned in a brief but fundamental. The discussion includes how to generate a wave of sinusoidal, nonsinusoidal waves and brief information about its use in the electronics field.
Sinusoidal wave
For those of you who enjoyed the field of electronic oscillators word certainly is not foreign. As we know the oscillator is an electronic circuit that works itself generates or produces electrical vibrations in the form of sine / sinusoidal. There are many types of oscillator generally operate on the principle of feedback (feedback) feedback means necessary to defend oscillasi. As already mentioned above there are three types namely sinusoidal wave oscillator pembangkil LC oscillator, RC oscillator and the Crystal Oscillator. Let's see how the workings of each type oscillator earlier.
LC Oscillator
There are many models of LC Oscillator but still has a similarity in principle it works.Among these models Hartley LC oscillator as shown in the picture. How it works series as follows. When this circuit is turned on, electric current flows through the RFC resulted in changes in collector voltage. Collector voltage changes are relayed by the C3 to the bottom of the coil L1 as well as energy supply. Since the middle of the L1 earthed (grounded) then the top of the coil L1 positive voltage makes the Q1 more rapid saturation. In the saturation state of the supply voltage to the coil L1 stopped. The energy stored in L1 fill Cl in negative polarity. Having been run out of energy absorbed by the C1, C1 dispose of its cargo through the L1 and the base of Q1.
Negative discharge voltage that is sent from C1 at the base of Q1 Q1 create clog (cut oil). After the charge C1 discharged, turning positive voltage from L1 C1 refilled while providing a positive voltage at the base of Q1. Q1 begin conduction again and the same events are periodically repeated continuously during the energy supply to the circuit is not disconnected. DC electrical current flow in the oscillator circuit is marked with arrows intact (solid).Electric current flows from the chassis to the emitter - collector and returned to the power supply (power supply) after the RFC. AC current is marked with dashed arrows. AC current (feedback) flows from the Q1 collector-to C3 - the L1 - and back to Q1. Output oscillators (sine wave) can be taken from the collector of Q1 with a coupling capacitor.
Qrystal Oscillator
Sequence generator (oscillator) sinusoidal wave Hartley model as discussed above with frequency deviation of 1% is still considered to be common and quite good. If the model had to be operated on a precision device that requires high stability, eg for electronic clock, it must be inserted into the circuit Oscillator Qrystal it as shown in the picture. If the oscillator works at the same frequency with frekuesi Qrystal it will obtain maximum feedback. If for any reason and other reasons oscillator frequency to shift up / down then qrystal impedance will increase to reduce feedback to suppress oscillator frequency back to Qrystal / OSC frequency. Qrystal oscillator frequency deviation at only 0.0001%. Very stable.
RC Oscillator
LC oscillator and oscillator Qrystal those discussed above are generally used in the RF (radio frequency). But for the needs of low frequency as the second audio frequency oscillator model was practical and less expensive. Then the RC oscillator is designed to meet the needs of low frequency. How kcrja quite simple RC oscillator (Lihal picture). When Q1 conduction, collector voltage decreases. Collector voltage phase shifted 180 degrees by the phase shifting circuit R1C1, R2C2, R3C3 so that the base voltage of Q1 gets positive feedback, making the Q1 saturation. Due to the saturation voltage base bias Q1 Q1 drops to the cut-off. When the cut-off Q1 Q1 collector voltage rises and the same process over and over. Q1 output sinusoidal wave form.
Nonsinusoidal Waves
There are a lot of nonsinusoidal waveforms such as rectangular shape (square), sawtooth (sawtooth), rectangular (rectangular), triangular (triangular) or a combination of two wave forms as stated. But in this chapter will only discuss two wave forms of the most common nonosinusoidal the rectangular wave and sawtooth wave.Nonsinusoidal waveforms are often also called "pulse waveforms." An electronic circuit that produces nonsinusoidal waves is called "pulse circuits." While the generator is called "blocking oscillator" for a square wave and sawtooth `blocking oscillator."
The Blocking Oscillator
Figure beside shows the basic circuit of a blocking oscillator. How it works as follows.: When the circuit is turned positive base voltage of Q1 gets forward bias circuit (not visible) so that the Q1 conduction. An electric current flowing through primary winding collector P. This current flow causes a positive voltage induced in secondary winding S is connected to the base of Qi through C1. Consequently Q1 rapid saturation. In the state of saturation induction voltage falls causing a negative voltage on the S, encouraging Q1 cut-off. Negatipnya dumping C1 through R1. When the charge Q1 C1 discharged back conduction. The same process is repeated. The duration of discharge C1 (Q1 cut-off / frequency) is determined by the value of RC. Square wave output is taken from the collector.
A basic blocking oscillator
Sawtooth blocking oscillator
In the practice of blocking oscillator was more often used as a sawtooth wave generator. Hence the blocking oscillator sawtooth See picture on the side. Sawtooth wave output circuit R1C1 is taken from the emitter of Q1. How it works much like has been described in previous chapters. When Q1 conduction current flows through P, generate positive induced voltage on the S, making the Q1 faster saturation. In the state of saturation voltage falls iduksi cause negative feedback on the S, encouraging Q1 cut-off. C1 positive potential makes Q1 fixed cut-off until the charge runs out wasted C1 through R1. Q1 conduction returned and repeated the same process. Frequency is determined by the value of R1C1.
Waveshape Conversion
Waveshape Conversion is a way to change the shape of a wave without affecting frequencynya. Schmitt Trigger is a sample converter or converter circuit sinusoidal waveforms into square waves. (See picture). Gelomang sinusoidal input signal is fed to form the base of Q1.
The output square wave is taken from the collector Q2. How it works, if the input voltage signal is below a certain level Q1 cut-off. In these circumstances positive cut-off voltage on the collector of Q1 becomes high enough erosive Q2 saturation. Q2 flows cause the voltage high enough to withstand high emitter Ql Ql remains cut-off. Ql will return conduction when the input signal voltage 0.7 V above the emitter voltage.The same process over and over again.
Another example is the Sawtooth Generator that can change the shape of a square wave into a sawtooth wave. (See picture). How it works. Positive input voltage causes the cut-off of Q2 and Q1 conduction. Constant current (because of R1, R2, Re) Q1 flows from long To fill C1 to T1. Due to the constant charging current output voltage flat-shaped slash / ramps. At T2 the input voltage change is negative, Q2 conduction causes the C1 voltage drop (cut-off) seiama T1 - T2. At T2 the input voltage change is negative, the cut-oiff Q2 and Q1 conduction. The same events over and over and over and over so that the output voltage sawtooth shape. Frequency output frequency depends on the input. Sawtooth wave is widely used in electronic equipment, eg televisions, computer as a high voltage generator.
Fequency
Wave sinusoidal, nonsinusoidal waves is called wave penodik because vibrate regularly within a certain time. The number of vibrations in one second is called frequency. To plant or type LC oscillator frequency magnitude is calculated using the formula:
LJntuk plant or type of RC oscillator frequency is calculated by the formula:
R in units of Ohm, C in units of micro farad Phi = 3.14.
