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

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Wien bridge oscillator LTSPICE

im looking for a good oscillator to implement in a circuit and I was trying to simulate a Wien Bridge oscillator in LTSPICE but I have no success as my output is always 0 V. Is there a special ...
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52 views

Do I need to use a programmable oscillator?

I can produce pwm signals with my mcu and I am intended to use this signal to feed another MCU's external clock input. But my output pwm signal voltage is 5V and I need peak to peak 2.5V signal and it ...
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0answers
64 views

How to use a crystal oscillator

I am trying to use a crystal oscillator as a clock signal for the PWMCLK input of a LED driver chip (TC62D723FNG) I have a FOX 1813-0245 8926 25.00000 MHz crystal oscillator I picked up at a local ...
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2answers
90 views

What is the tiniest, low-power, and efficient am transmitter?

Here are my constraints: I need to build an am transmitter, but it has to fit in a 1 inch diameter and ~1 inch height box. Since the box is very small, I plan to use a CR2032 battery, which is also ...
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1answer
42 views

Loop Controlled v. Full Swing Pierce Oscillator

I am going to be working with the Freescale MC9S12XE processor and trying to figure out the oscillator configuration. They offer the following options: Loop Controlled Pierce Oscillator Full ...
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1answer
56 views

Trouble with phase locked loop: phase comparator is just showing the VCO output (with picture)

I am using the CD4046BC for the first time, and do not understand something that is happening. I am using the type I phase comparator, which is just a simple XOR logic gate. When I have the input as a ...
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1answer
55 views

Will a 5V crystal oscillator oscillate with a 3.3V supply?

My question is in the title. I was looking for a component, but I can only find it with 5V. There is no data sheet provided so my question is in general: Will a 5V crystal oscillator oscillate with a ...
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39 views

Crystal oscillator output impedance

I want to build a varactor frequency tripler (from 80 to 240 MHz). Can't find XO output impedance for an input matching network. I would appreciate any advice on this matter.
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1answer
48 views

Review and question about AD9838 circuit

I have tried to come up with a schematic of using AD9838. I used the eval. board schematic and modified it to my needs. The eval. board schematic can be found on page 9 here: AD9838 eval. board ...
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2answers
150 views

How to test a crystal resonator in board?

I have 2 quartz crystal resonators in my pcb board: 32.768 kHz & 20 MHz. They are connected to a Freescale MC12311 transceiver IC, which has an HCS08 micro-controller embedded in it. I want to ...
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1answer
63 views

zvs induction heater mosfet failure?

Hey guys my name is Barrett I'm an electrical engineering student and I'm new to the forums. I've been super excited to put a zvs induction heater together and I finally got all my parts turned it on ...
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5answers
90 views

Control resistances with voltage

Let's say I have an audio oscillator, which a resistor varies the tone. I have 5 different voltage sources, each representing a tone. How can I control the tone (vary the resistance) depending on ...
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3answers
79 views

What does FCY / F_CY stand for?

I've come across many equations in microchip datasheets that are based on this value and am looking for a central place to lookup definitions. F_OSC = oscillator frequency T_CY = 1 / F_CY = time to ...
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0answers
70 views

Why does my crystal oscillator spike so much?

I just got a new oscilloscope (Rigol DS1102E) and I'm new to EE in general. One of the first things I put on the scope was my 3.579Mhz "TKD" crystal oscillator. ...
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1answer
105 views

how do oscillations build up initially although the circuit has no external applied input? [closed]

In practical we got some king of oscillation even before given input power. We have built wien bridge oscillator like this one. . image from electronicdesign.com
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82 views

simple schematic for 10.7MHz crystal-based marker generator

For FM tuner alignment purposes I want to build an outboard 10.7MHz marker generator to use in association with a piece of gear (ST1000A) that doesn't have one built in. They used to be available in ...
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1answer
49 views

What is the oscillator used for on HT12E/D? [closed]

Every tutorial I've found on the internet connects the oscillator in and the oscillator out with a resistor. What can these ports be used for?
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0answers
45 views

Can any one tell me the purpose of those two capacitors at the both end of XTAL1 and XTAL2 connected to crystal oscillator? [duplicate]

How does those two c2 and c1 capacitor affect clock input spectrum? What would happen if those two capacitors were not there? Are they mandatory to have?
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43 views

Difference between 3.3V half-size DIP oscillator and Full size DIP oscillator

I have often heard oscillators with 3.3V half-size DIP oscillator with 4 pins and Full-size DIP oscillator with 8 pins. Why would someone want to use half-size DIP or full size DIP?
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1answer
51 views

How is the negative resistance feature of tunnel diodes used in oscillators?

Can someone explain how the negative resistance feature of a tunnel diode is used in oscillators with the help of this circuit diagram:
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2answers
58 views

How does spread spectrum VCXO (voltage controlled oscillator improve EMI on your board?

I have seen people adding spread spectrum voltage controlled oscillator to EMI on the board, How is EMI affected by single spectrum crystal and with spread spectrum crystal.
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1answer
63 views

Crystals as RLC circuit? How?

What gives the crystal oscillator a property of Inductor? How does energy transformation between electrical field and mechanical stress and strain makes oscillator work like a Inductor? I know how ...
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0answers
83 views

Adjustable oscillator using 74LS04

I'm looking for a schematic to build an adjustable oscillator using the IC 74LS04. I'm not very expert. I've found this schematic: Is possible to achieve something similar? I'm looking to make an ...
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1answer
93 views

Down converting square wave

I'm making some experiences with relaxation oscillators using 74 series. I'm trying to down convert to square wave but I get confused. Let's say I have 50khz square wave frquency generated with a ...
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1answer
77 views

XR-2206 as a VCO for a synth

I was wondering if the XR-2206's pitch was controlled by It's Vcc or by it's RA? Im a little confused when it comes to how I would get the output from a keyboard(after it is changed to voltage) to ...
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0answers
48 views

Right component values for a monostable (one-shot) oscillator

I'm designing a monostable oscillator to take the rising edge of an audio signal- a recorded slow-pulsing heartbeat- and have it signal a solid-state relay, holding it open for about .6 seconds. I ...
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1answer
102 views

Designing an Oscillator

I'm tired of having to resort to Google to find every single oscillator design. I would usually just try to search for a circuit using the same frequency crystal, and try to build that. Right now, I ...
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1answer
121 views

Determine polarity of crystal oscillator [closed]

A two-pinned 13.824 MHz crystal oscillator broke away from the pads on a PCB board. One pad is labeled + and the other is GND. Do two-pin crystal oscillators have specific polarity?
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1answer
62 views

What's the function the network outside a crystal oscillator connected to an IC?

Take a look at this: Then general network is commonly seen when connecting an oscillator to an IC. What is the purpose of this network? Is there an article I can read on it?
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1answer
121 views

Crystal oscillator in schematics

What the numbers 1 and 2 mean next to Crystal oscillator in hardware schematics? I tried to search online and went through about 20 lists with component symbols, but non had the numbers nor ...
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2answers
50 views

PIC24 PLL configuration

My PIC datasheet (PIC24HJ128GP202) specifies three parameters to configure the PLL which are N1, N2 and M. Each of them have to satisfy some clock frequencie ranges in input/output of each block ...
2
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1answer
63 views

PIC24 PLL initial value

I'm setting up my PIC oscillator frequency and I'm using a PIC24HJ128GP202. From what I've seen in the datasheet, two of my total options were to use a crystal or a internal oscillator (FRC) which ...
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2answers
102 views

Trouble simulating Colpitts in Multisim

I've been trying to get a Colpitts oscillator to work with multisim, following this schematic, which I found in a book (I just copied it): Yet, it does not work, all I get is a 0 voltage signal ...
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3answers
342 views

crystal oscillators connected in parallel

why there are two crystal oscillators connected in parallel in the circuit above? i am familiar with the configuration of Q2( look at the schematic) but what is the purpose of Q3? do i really need ...
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45 views

Delay line blocking oscillator

I'm trying to understand how this delay line oscillator does works. Is that based on common base configuration. Could anybody explain it's mechanism with equations. And what does that delay line ...
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0answers
84 views

How does this oscillator work?

I was looking around for simple oscillators to breadboard and found this. I used 100K resistors for R1 and R2, 1K resistors everywhere else, 470nF for the capacitor, and BC547 transistors. I chose the ...
2
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1answer
61 views

Understanding crystal resonator symbols - which one is 24Mhz?

So, I'm in need of a 24MHz crystal to drive an AVR microcontroller. I've got some crystals that I've desoldered off some old, useless equipment. I've found three crystals that have '24' on their ...
3
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1answer
82 views

Do I need an external oscillator for PIC16F887A?

I'm working with a PIC16F877A. Do I need to add another external oscillator to pins 13 & 14 or can I use its internal oscillator with 4MHz frequency? I don't need precise timing in my project. I ...
5
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1answer
59 views

Working of a Comparator based Oscillator Circuit

I was trying to understand the working of this circuit, but couldn't figure out, how does it generate a square wave. Here is what I figured out by looking at this. The Op-Amp behaves as a ...
17
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1answer
399 views

What effect does selecting the wrong load capacitance for a crystal have?

I've seen questions such as this one and this one that talk about selecting capacitors that, in series, match up as closely as possible to the load capacitance of the crystal. What effect does ...
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1answer
120 views

Opamp relaxation oscillator (single supply)

I simulated and built current circuit. What I got was a rectangular wave generator with a duty cycle significantly lower than 50%. Than I made R3 = R4 and got 50% duty cycle. I managed to think ...
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1answer
53 views

Crystal and Oscillator [duplicate]

I know that crystal oscillator is a type of oscillator. But why in colloquial terms crystal is different from oscillator and how they are physically different?
2
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1answer
195 views

Oscillator for High Voltage Transformer: RLC or Blocking Oscillator

What type of oscillator is being used in the schematic? How is that particular oscillator working in this circuit? I'm less than confident with oscillator theory, and I can't tell if this is RLC or ...
2
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1answer
131 views

Why do the satellite manufacturing companies themselves make their crystals?

Yesterday, I saw this documentary>How To Build A Satellite(look this intervals->27:29 - 30:16) and after see it, I had a question but I couldn't find any answer for it. my question is this: Why do ...
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2answers
84 views

How does positive feedback generates ac waveforms in an opamp?

How can an ac oscillation be obtained by using an opamp and some components and what is the working principle behind?
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1answer
50 views

Error in dsPIC33 Family Reference Manual Oscillator?

I'm using an external 20MHz (categorized as high-speed or HS range) resonator and using PLL, but I'm not able to clock the device up anywhere near the max cpu speed advertised. How are you ever ...
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2answers
96 views

Why is it said that in practical cases loop gain of an oscillator should be slightly greater than unity?

Recently I read about oscillators and I noted a sentence. It is said that in practical cases the loop gain should be somewhat 5% larger than unity. Why is it said so?Will it result in increasing the ...
2
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2answers
302 views

How is Crystal Oscillator implemented in digital circuit to generate clock frequency. What part of crystal oscillator makes the clock signal?

How is Crystal Oscillator implemented in digital circuit to generate clock frequency? What part of crystal oscillator makes the clock signal? I know the fact that crystals has its resonating ...
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1answer
99 views

What limits system clock in MCU? How high can I go?

I'd like to produce PWM outputs at f_PWM ~= 100kHz and I'd like to connect the ADC to sample at least once during each high-time interval of the PWM output. Everything in my configuration of these ...
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2answers
170 views

Create a simple oscillator using relays?

Is it possible to create a very simple oscillator using relays to cause the current to quickly switch back and forth between two lines (or even pulse on one)? It seems like it's almost possible, but I ...