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

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47 views

Esaki effect implementation on simple oscillator circuit

Hello guys I am trying to learn basic oscillator circuit with the help of this link. But when I connected components My lead is not blinking rather it is giving bright light.If Components I have ...
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1answer
33 views

Damped RLC Circuit Equation

I'm trying to measure the inductance of a toroid with the use of a 555 in astable mode. Hopefully, by putting the toroid in parallel with a known capacitor and driving the circuit with a low duty ...
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0answers
17 views

Square wave oscillator (up to 5kHz) from -40V to -10V (approximately)

I want to test a depletion mode TFT which has a turn on gate voltage of about -35V and consequently I want to show that this TFT can be used as an inverter and find the maximum frequency at which it ...
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2answers
49 views

bubba oscillator

i am trying to make a sine wave generator. the Bubba oscillator circuit given below should produce 53 Hz. according to the text book " Op-AMP for every one", the circuit should have gain = 4, and the ...
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0answers
27 views

PIC12F simulator: Why isn't the oscillator running?

I have written firmware for a PIC12LF1572 that I am testing in the MPLAB X simulator. The program runs and correctly responds to stimuli, except when it needs to wait for a timer interrupt. After a ...
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23 views

How to use external clock on STM32F205VC?

I'm using VisualGDB for stm32F205VC programming. I have an external clock on my board connected to OSC_IN and OSC_OUT that I have to use. How to switch to it?
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1answer
40 views

When we need external crystal for atmega?

I created microcontroller circuit, refers to most of circuit in internet. Which is it is using external crystal. As i know now, that atmega16 has internal oscillator by default 1MHz. So, ...
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2answers
65 views

Numerically Controlled Oscillator (NCO) Sample quantity

Ive been doing some research on NCOs and some initial information (or lack of information) is bugging me. Ive read a few articles on this topic: FPGA based NCO Blog on NCOs But i still don't ...
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45 views

Lc tank resonator vs. quartz crystal?

For Colpitts and Hartley oscillators, which is preferable to use: an lc tank resonator, or a quartz crystal? I've built Colpitts oscillators with both an lc tank circuit resonator, and with a quartz ...
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1answer
49 views

Operating frequency of microcontroller PIC18f4550

I am new to PIC Programming, and thought of blinking LEDs as my first project. Now I copied a code from net which blinks two LEDs and its working, the LEDs are blinking. My settings:- I haven't ...
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58 views

tunable oscillator circuit: get rid of the variable capacitor

In these days I'm doing some experiments with oscillators circuits; I've built an oscillator circuit which is tunable using a variable capacitor (the range in picofarad of this variable capacitor is ...
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1answer
57 views

How to convert this FM transmitter to receiver?

I made this circuit and it works properly but I need to make an FM receiver using the same idea of this circuit (common base). Would you tell me what changes should I make so that the circuit is able ...
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1answer
59 views

Calculating the gain and phase shift of a phase shifting circuit

I want to calculate the gain and the phase shift of the phase shifting circuit below. My approach is to derive equations to different meshes using Kirchoff's law, and then calculate the ratio between ...
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0answers
21 views

Clipped sine input for HSE clock input on STM32F303?

I am using a STM32F303 and need a very high stability clock ie around 1ppm over temperature. One of the modules I am looking at outputs what is described as "clipped sine". Can this drive the ...
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1answer
72 views

Why are shorter leads preferred over longer leads?

I'm building oscillator circuits on a copper plate for an RF design class using the dead-bug method. I know that short leads between components is preferred over long leads, but why is this? I heard ...
3
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1answer
55 views

How do I find spectral purity?

How is spectral purity measured? or evaluated? I have this signal coming from a 10 MHz crystal oscillator. I know how to calculate the SNR, but how do I calculate the spectral purity? Is it also a ...
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3answers
56 views

How does oscillator frequency stability affect timing? [duplicate]

If, for example, a crystal oscillator is specified as +/- 100ppm what does that mean? That the exact frequency is uncertain to that degree, or that the frequency varies by that degree over normal ...
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1answer
50 views

One crystal oscillator for multiple clock inputs PCB tracks topology

When sharing a crystal oscillator output to multiple clock inputs, what should the oscillator output PCB tracks topology be ? Should they go from the oscillator output to one clock input to the next ...
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1answer
65 views

blinker circuit theory

simulate this circuit – Schematic created using CircuitLab A simple light bulb blinker circuit.......R4 is the bulb..I'm pretty sure I understand the functionality here. C1 initially ...
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2answers
65 views

Hartley Oscillator Alternate Oscillation Mode

I've been trying to build a hartley oscillator and have almost succeeded, however my calculations are off by appx 1000 relative to the measured waveform. AND the kicker is that it only works when I ...
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0answers
43 views

Colpitts vs. Hartley?

What are the pros and cons of using a Colpitts or a Hartley configuration for an oscillator?I know that the difference between them is the form of feedback, but does one or the other perform better ...
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0answers
51 views

Superheterodyne receiver with voltage controlled oscillator

I'm new in electronics and I want to create a FM receiver that performs a product of the received RF signal and a local signal (the local signal is also frequency modulated with a Voltage Controlled ...
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1answer
64 views

How to increase power of a wireless power transmitter circuit?

I designed this circuit for a frequency of 2MHz, but I get an output of 7mW. I need to increase the output power up to at least 10 to 20W. Help me to redesign the circuit. Consider the transformer ...
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2answers
70 views

Understanding a simple crystal oscillator transmitter circuit

I've recently built this circuit: http://makerf.com/posts/mighty_simple_shortwave_transmitter It works on the desired frequency as you can see from this video : ...
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2answers
121 views

What makes a crystal oscillation to begin

I'm trying to understand how the Pierce oscillator works. I started from the very beginning and I'm looking into the crystal resonator. Thanks to this answer How does a Crystal work? I've managed to ...
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27 views

asymmetric oscillator layout

Due to space and redesign time concerns, the crystal I'm using cannot rotate. I'm updating the circuit to hopefully make the clock as robust as possible. I have copper keepout in the dotted area ...
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71 views

Can any one give reason for this configuration of oscillator

Please give reason why this is is Common-Base configuration with Base feedback.
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4answers
96 views

How do crystal oscillators work with feedback consisting of CMOS inverters?

For a crystal oscillator to work, there must exist a feedback path with properly designed specifications in order for all to work as expected. Broadly, the basic form of this control system is as ...
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47 views

Why would the Schmitt trigger relaxation oscillator a bit unstable?

This thing oscillates from time to time. Why? (Respect part numbers, all chips from NXP) simulate this circuit – Schematic created using CircuitLab ...
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2answers
34 views

confused about behavior of relaxation oscillator

I'm just starting to learn about electronics by working through Charles Platt's Make: Electronics book and I'm on experiment 14, which is a relaxation oscillator for an LED. I should note that in the ...
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2answers
85 views

Why there is many configurations of Colpitts oscillator?

I would like to understand how colpitt's oscillator works but I'm confused because there are many configurations on the internet and I don't know what is the difference between them. For the next two ...
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2answers
92 views

square wave generator on 20MHz

I need a circuit that generates rectangular waves. It shouldn't be lo-hi-lo-hi, but a random sequence of lo-hi-hi-hi-lo-lo is needed. It also has to oscillate like that, at at least 20MHz. I don't ...
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1answer
85 views

ATmega162 fuses to select external clock 12Mhz?

Could anyone tell me how I could change the fuse bit, so that my ATmega162 uses 12 MHz external crystal. Once, I made the changes in the AVR fuses wrong the AVR went dead. That is why I need ...
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2answers
199 views

How does the negative feedback in this oscillator work?

EDIT: I don't think I'm using the term "negative feedback" correctly. What I meant is, how does the feedback that makes the closed loop gain equal to 1 work? I'm trying to understand the very basics ...
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1answer
64 views

maximum voltage that a colpit oscillator can withstand

I am working on a wireless power transfer project using, I need to design an oscillator. I need a frequency of over 2MHz and I need it for a high power application. So my question is what is the ...
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2answers
71 views

Can one always drive oscillator inputs with a single-pin oscillator output and bypass the integrated feedback circuitry?

Very little is written in the MCP2211 datasheet regarding the oscillator input configurations. The microcontrollers I have been using lately allow you to use the self-powered, single output ...
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2answers
138 views

LC Oscillator, Tank Circuit

How does a tank circuit work with a dc power supply? I understand that if you charge a capacitor that's in parallel with an inductor and then remove the power supply then the capacitor and inductor ...
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3answers
109 views

Slightly weird astable oscillator in a 555, where does this capacitor discharge to?

In the 555 datasheet, the cap is usually connected to pin 7 (discharge), but in this circuit, it's not: When the capacitor voltage is >2/3Vcc, output will turn off and current will have no where to ...
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3answers
204 views

What is the wrong with this simple sine wave generator circuit?

I've designed this circuit myself aiming to generate sine wave at the collector of the transistor, but I doesn't work. the current at the collector is DC. Is it a simulator error or the design is ...
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1answer
48 views

Need help with Relaxation Oscillator with Parasitic Capacitance

I am trying to build a capacitance meter using a simple relaxation oscillator with a fixed resistor R in series with a capacitor to be measured C. I am applying the formula where Freq=frequency and K ...
4
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1answer
409 views

PIC18F4550 External Oscillator

I am currently trying to get the configuration bits set up to blink a LED with a 20MHz external crystal. It is operating correctly using the internal oscillator, but does nothing with the crystal, and ...
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3answers
60 views

Simple switching between clocks using oscillator disable pins

I am working on a circuit where I need to use different clock sources. I am using two HCMOS oscillators. Both oscillators have an disable pin. When disabled, the clock output buffer is placed in ...
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0answers
48 views

Question about an LC oscillator

I saw a previous question about an LC oscillator and I wanted to know how it works. What I figured out is, that the current across R2 is approximately always constant (Q1 base current doesn't drop too ...
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2answers
99 views

PIC24 Primary Oscillator XT_PLL frequency is off by 3 percent

I am using a PIC24. After solving the issue with the PLL (PIC24 PLL module is always out of lock) I am struggling with large variation in the system frequency. I wrote a small code that is used to ...
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2answers
95 views

Is an LR Phase Shift Oscillator possible?

All the phase shift oscillators I've seen use RC stages each of which produces a 60degree phase-shift. Is it possible to inductors instead of resistors? My understanding is that inductors also cause a ...
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1answer
108 views

PIC24 PLL module is always out of lock

I have been working on a PIC24FJ128GA310 development board for for some time now and recently got a PCB made. If I try to move my code into the new board all timing related math and functions are ...
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1answer
142 views

Colpitts oscilator - purpose of voltage divider

I'm confused by the Colpitts oscillator shown below: I've marked my understanding of the various components, but I'm having trouble understanding the tank circuit. My understanding is that C1 and ...
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0answers
86 views

Colpitts Oscillator, purpose of capacitor

Today, I built a colpitts oscillator, using information from various sources I found online. The schematic is as follows: And a picture of the build and some waveforms are here. There are several ...
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1answer
81 views

How to generate Duty Cycle from DC without 555

I am currently working on a simple circuit which includes creating duty cycle from DC. Also, I need to change it's pulse width with time. I have decided to use op-amp relaxation oscillator to produce ...
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50 views

Tank circuit resonance sometimes 3x expected value

I've been reading about Tank circuits, and wanted to try and see if I could see the resonance on a scope. I used a 22nF capacitor and a 10uH inductor, I wrote my notes up here. Some of the time I saw ...