A device or circuit that generates an AC signal at a certain frequency.

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80 views

Help with a RF reciever circuit

Recently I have been working on a basic RF receiver, but my efforts so far have proved fruitless. I designed the following circuit based of of previous research into the topic. According to what I ...
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1answer
41 views

Problem in Clapp oscillator

I've set up this circuit on breadboard ( C1 being electrolytic and others disk) with Q1 as 2n3904. The simulation is perfectly fine and the oscillator works in the simulator as expected. However, ...
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2answers
71 views

What are quartz crystal oscillators?

I'm a beginner in electronics and I found two quartz crystal oscillators, each one has two pins. Their numbers are: sjc4.000a ee4.000 Is it possible to know the ...
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1answer
41 views

How to configure PIC24F oscillator?

I'm coding on PIC24F and I'm still fighting with oscillator configuration. Between configuration bits and SFRs such as CLKDIV and OSCCON I am a 'bit' lost... I've been making things work by trial and ...
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2answers
98 views

How to make an easy oscillator?

I want to make a very simple oscillator that produces the sound of telephone ringing (I want to make a ringer). I will not connect it to a telephone so the quality of the sound is not important. I ...
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3answers
65 views

Crystal or Crystal Oscillator for time sensitive device

A device that I'm working on is controlled by ATmega328P microcontroller. This will be some sort of a watch, therefore I want it to be as precise as possible. For instance if left to run for a whole ...
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1answer
20 views

Input / output voltage standards for modular analogue synthesizer

I'm investigating building a modular analogue synthesizer, and learning electronics along the way. I want to get a firm understanding of the supply voltage, inputs and outputs specification that is ...
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1answer
72 views

Crystal clock oscillator giving out sine wave, help?

I am building a 50MHz clock by using ABRACON ACOL-50-EK crystal clock oscillator. I have connected 3.3V supply (with a 0.1uF capacitor to ground) to Vdd (pin 14). GND (pin 7) is grounded and output is ...
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95 views

External oscillator problem

I have this sample program to blink LED with PIC18F4550 using external oscillator. I'm using a 20.000 MHz crystal oscillator with 30pF capacitors. The problem is when I wire the capacitors the the ...
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0answers
35 views

Crystal Oscillator output voltages and power

I have built the crystal oscillator stage to the Pixie 2, a Hartley oscillator, with a 9 volt voltage source. I measured the output with my VOM set to AC 30 volts. It read almost 30 volts. That is ...
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247 views

Common Emitter not amplifying

I am trying to make a 27 MHz carrier wave transmitter from a crystal oscillator and a secondary amplifier. Thi is the complete circuit: simulate this circuit – Schematic created using ...
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2answers
82 views

Simplest possible oscillator (with some constraints) [closed]

I'm interested in finding an oscillator circuit that meets the following constraints: Runs on 9 volts or less Periodicity 100-1000 Hz or so Non-sinusoidal oscillation No inductors 1 transistor or ...
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1answer
32 views

Analyzing/designing positive feedback amplifier

I've been searching all around to find a tutorial on analyzing/designing a positive feedback amplifier, especially a single transistor in common collector mode, but with no luck... So, lets say I ...
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1answer
37 views

Colpitts VCO by varying base voltage

I've noticed that if I build a Colpitts oscillator (audio range) using a transistor in the common base configuration (similar to the circuit here) I can vary the voltage on the base and get a wide ...
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2answers
201 views

What type of oscillator is this? (Theremin Project. Variable Pitch / LC Oscillator)

I found this oscillator at a Theremin project pdf. I simulated the circuit, and found that the output (left wire) oscillates at 236.5 kHz. This circuit is referred to as "Variable Pitch ...
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1answer
35 views

Wien Bridge Frequency Selective Network Frequency Response Proof Exam Question

So this is part of the solution to the proof of what the frequency response on the frequency select section of the Wien Bridge oscillator. What I don't understand is how the answer are equal to ...
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4answers
408 views

Why don't infinitely many sinusoidals exist in an oscillator circuit?

A sinusoidal oscillator, takes the ambient thermal noise or any imbalance in the circuit as input and gives out an oscillation. This kind of oscillators are called to be linear. By the nature of a ...
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2answers
59 views

Keeping output of a phase shift oscillator in-phase with another sinusoidal signal

I have a sine wave source and a phase shift oscillator which gives out sine wave. The sine wave source is not always enabled. It may be turned of in arbitrarily time periods. I want the phase shift ...
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1answer
405 views

Why doesn't my opamp relaxation oscillator oscillate?

I have designed a relaxation oscillator with an opamp. It is supposed to oscillated at 50Hz, but it doesn't. I haven't built a physical circuit, I'm trying to simulate it in CircuitLab. I calculated ...
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1answer
66 views

How to tune a radio receiver using a crystal oscillator?

I'm building my first radio receiver (a simple Ramsey HR-40 kit). The "Alignment" section of the instructions requires that I have some other device which I tune my receiver to. Since I have no such ...
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3answers
144 views

Getting the right frequency from an oscillator circuit

I have constructed an oscillator circuit using the resistor and capacitor values shown in the diagram above (from the Proteus ISIS simulator). I run the circuit and use a switch to trigger the ...
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3answers
130 views

how does current go to infinity in an ideal LC circuit at resonance?

Consider an ideal LC series circuit, excited by a sinusoidal source at resonant frequency. Assume zero initial conditions, for capacitor voltage and inductor current. simulate this circuit ...
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1answer
55 views

how to select capacitor for a crystal oscillator

Here is a 32 MHz crystal from one of TI's reference design The BOM list defines the crystal as ...
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1answer
99 views

Oscillator problem

I was designing an oscillator for HF range. Although both the circuits are same, the first circuit doesnt work while the second one does, despite the fact that the varicap used has 17 pF at 20 V. ( ...
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1answer
56 views

pic16f628a internal oscillator setup error undefined symbol “INTOSC”

I want to set internal oscillator for pic16f628a, according to datasheet page 96, I have to set FOSC_INTOSC, but I get this error ...
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1answer
67 views

What is the conductance of this LC tank?

So, I start with total conductance: $$ G_{TK} = \frac{1}{\frac{1}{j\omega C}+ 2R_C} + \frac{1}{j\omega L + R_L} $$ Then, when I take only the real part of this expression in order to know the ...
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2answers
74 views

Why Inductor reactance 180 ohms?

Why is the inductor reactance 180 ohms for designing Voltage controlled Oscillators ( or oscillators maybe ?) I came across a few resources for designing oscillators, colpitts and hartley ...
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1answer
226 views

Why does this regenerative receiver not just turn into an oscillator?

I'm trying my hand at making a radio transmitter and receiver and I'm not sure exactly how this receiver works. I understand its a continuous wave receiver which is good for on/off transmission. I'm ...
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47 views

Crystal Oscillator Output Amplification

I have a HCMOS Crystal Oscillator at 50 Mhz (DataSheet). With an ac coupling and pi network I generate a sine wave with 50 ohm output impedance. In standart bjt oscillator circuits, one need to make ...
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3answers
2k views

How does a Crystal work?

Specifically, a 2pin and 4pin quartz crystal oscillator. What I know: current is applied and the crystal oscillates in order to provide an oscillating signal. What I want to know: How does the ...
2
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2answers
78 views

Can oscillators be made from a single supply?

Oscillators such as a Wein-bridge sinusoid or a square wave Schmitt trigger oscillator. Is it possible to bias these so they oscillate above 0V?
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0answers
30 views

Microwave Oscillator: Both Ports Unstable?

I'm just wondering, for microwave oscillators, I think both ports need to be in the transistor's unstable region. What would happen if just one port were in the unstable region and the other in the ...
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1answer
73 views

Proper oscillator for CPLD

I plan to use KC5032A40 as a clock source for CoolRunnerXPLA3 256. I power it with 3.3V and interface it as suggested: I perform the measurement at the Test Point and do not add any CL capacitance, ...
4
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2answers
98 views

Why use asymmetrical capacitor values for crystal?

Are there any circumstances where you would want asymetrical load capacitors on a crystal? I came across this schematic in the documentation for an NXP UART. It looks just wrong to me. Can anyone tell ...
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2answers
67 views

Ring oscillator frequency

According to Barkhausen's criteria, for oscillation the feedback should be made after phase difference of 2pi and gain has to be >=1. Now when I consider a ring oscillator if 2 inverters are ...
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1answer
231 views

Crystal oscillator wave shape?

I hooked up a crystal oscillator (4 pins) to Vcc + Gnd and observed the generated waveform using my scope. I think everyone will agree the waveform shown is very distorted and I am not sure why. Any ...
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2answers
114 views

Crystal Oscillator design with no data sheet

I am a newbie to circuit design and I need a 50MHz clock. I went to a local electronics store and got a 2-pin radial Quartz crystal. I do not have a data sheet for this. The only markings for the part ...
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2answers
68 views

Analyzing clock oscillator using timing diagram

In a recent examination a friend of mine was asked to analyze and find the frequency of oscillation of a clock oscillator using timing diagram as shown below: Can someone give me directions as how ...
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1answer
76 views

connecting oscillators in parallel to increase current

I am trying to power an alternating current coil, and was wondering if I can connect the output from transistor oscillators in parallel to increase the current, like you can with batteries. I don't ...
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1answer
133 views

Correct 4-pin Oscillator connections

I'm looking for the correct way to connect a 4-pin oscillator to a PIC24F. I have seen diagrams like the one below, but it seems that this connection is only for crystals and not crystal oscillators. ...
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2answers
140 views

What do Capacitors do in a System with a Speaker?

I made a circuit based on a diagram from my physics teacher. The circuit has a 555 chip connected to seven wires that make up a circuit. The circuit includes a photocell resistor that acts as a ...
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1answer
62 views

Audio oscillator cross-talk on small synth project

I am making a small 9V battery powered synthesizer with a square wave oscillator built around a 40106b Schmitt trigger (reference: http://richdecibels.com/blog/?p=11) and a few other components, one ...
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1answer
65 views

A voltage-controlled oscillator? [closed]

I need to identify a circuit from its function. So, here is the block (called OCT): I only know that the components are organized in the following manner: Where INT is an integrator, COMP is a ...
4
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2answers
445 views

What components are needed for a 20MHz square wave clock?

I would like to create a 20Mhz clock that generates a square wave for the home-brew Z80 computer I' making. I already have several 20MHz crystal oscillators but am at a loss when it comes to circuit ...
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3answers
211 views

RC phase shift oscillator : how to give positive feedback?

why is negative feedback given in a rc shift oscillator although a oscillator requires a positive feedback? as shown in this figure. And as shown here positive feedback is given by connecting the ...
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1answer
43 views

Buffers in oscillators

Simple question. Consider positive feedback electronic oscillators. Imagine the amplifier I wanna use has an input impedance which is non infinite. Is it a buffer always meant to be put between the ...
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1answer
46 views

DC Air pump oscillator - square vs sine

I have an air pump that currently runs on AC, but I want to run on a solar/battery system that's 12V DC. The internals of the pump include a transformer to reduce voltage from 120 (I haven't been able ...
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1answer
122 views

HEF40106BP oscillator output frequency [closed]

I have a NuTone four note Door Chime, Mod# LA500K. I want to slow the chime cadence. There are two ICs: CD4017BE & HEF 40106BP. Can someone tell me if this is possible and how? (RC circuit?) ...
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3answers
1k views

Deriving the formula of oscillation frequency for the Phase Shift Oscillator

My aim is to find the oscillation frequency of a Phase Shift Oscillator. I start by finding transfer function of the cascaded RC network. $$ V_o(s) = \dfrac{\dfrac{1}{C_3s}}{R_3+\dfrac{1}{C_3s}} ...
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2answers
656 views

Working of Wien Bridge Oscillator

I am studying Wien Bridge Oscillator. The part I do not understand is how the other frequencies die out. For example, let us say initial disturbance was not of the resonant frequency but a higher ...