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Questions tagged [oscillator]

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

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4answers
109 views

How to radiate a positive oscillating voltage?

I am trying to build a simple AM transmitter, transmitting only a carrier wave and thus silencing the noise on my radio standing next to my circuit. I built this circuit on a breadboard. It's a ...
0
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1answer
25 views

NMOS limiting circuit for Colpitts oscillator

According to my book, the amplitude of the output sine wave produced by the following Colpitts oscillator should be limited by transistors M1 and M2. We only get a final answer without reasoning and ...
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3answers
1k views

What is meant by 'local' in local oscillator?

We know that a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. But what do we mean by 'local'? How is 'local oscillator' different from ...
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4answers
83 views

Can’t reproduce oscillations using a simple inductor capacitor circuit?

I’m trying to reproduce a simple oscillator conductor / inductor circuit as shown here. I replicated exactly the same scheme on a breadboard and check all the connections using a led However when ...
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0answers
35 views

CLOCK USING 16F876A

I have constructed a 7-segment clock using DS1307 & PIC16F876. The clock runs well except that after some time (after 10 to 12 hours running) display freezes. After resetting, original time is ...
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1answer
64 views

Vary the Vpp of sinusoidal oscillator

For an assignment I have to create a sinusoidal oscillator with 5 Vpp (centered around 0 V) oscillating at 10.0 kHz. The oscillator works as expected, at the right frequency, but the voltage needs to ...
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3answers
95 views

crystal oscillator Application

(Note: I am aware that crystal and oscillators are two different things but a lot of people use them interchangeably so I am using it in the title.) My question is about Oscillators, all oscillator ...
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1answer
35 views

Can I use the oscillation frequency equation for this circuit?

I'm not really sure if this is a question that can be answered so I'm sorry in advance if it isn't. I've just started doing electronics on a breadboard and I'm making a "Mini Strobe Light" from Jaycar'...
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2answers
52 views

Low-impedance tap in this oscillator circuit

Here is the schematic of Michigan Mighty Mite, a popular transmitter circuit design. It seems to be quite close to a regular feedback oscillator, with a few peculiarities. What puzzles me is the ...
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0answers
23 views

MOSFET Switch for Tuned LC Tank

I am trying to implement the circuit as shown below. I essentially want to be able to control the gate voltage of the NMOS to change the resonant frequency from 5GHz to 2.5GHz. For a transistor size ...
0
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1answer
35 views

Link between phase noise and linewidth for a oscillator?

I was googling for a formula to transform the dbc/Hz value given in data sheets for VNA, spectrum analyzers and VCO is often given in dBc/Hz with offset. Now looking up research papers about future ...
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1answer
99 views

Crystal oscillator replaced with exact frequency for clock?

I'm repairing my Nintendo Donkey Kong arcade PCB and I have no pulse when tested with my logic probe. I found out that the crystal oscillator (2 pin HC-18U) was not connected to the board, since the ...
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1answer
49 views

Single supply opamp colpitts oscillator

I'm designing a Colpitts oscillator with a single supply rail-to-rail opamp powered with 3.3 V. The positive input of the opamp is set to VDD/2 to offset the negative part of the oscillations so ...
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2answers
59 views

Can I use MCU's internal oscillator when communicating with GPS and cellular modules?

Can I use MCU's internal oscillator when communicating with GPS and cellular modules? I want to avoid connecting external crystals for the MCU since they generate noise, extra components, extra costs, ...
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4answers
98 views

Confusing quartz crystal impedance graphs

I thought that at the series resonant frequency of a piezoelectric oscillator the impedance of the crystal would be the lowest, and at the parallel resonant frequency the impedance would be the ...
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3answers
73 views

What actually is the load capacitance of a quartz crystal?

I'm having hard time understanding the principles of piezoelectric crystal oscillators. I've found this picture: I understand that "load capacitance" is something you have to connect to a crystal. I ...
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3answers
151 views

Rectifying failed MCU crystal oscillator design

I am working on an SMD hobby project (2 layer board) where I use a STM32F405 MCU running at 3.3V, clocked from a 25MHz external crystal. Being impatient, I hastily designed a board and ordered it. ...
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4answers
49 views

What is a fast built in op-amp to use in OrCAD Pspice Capture? Or how can I design one?

I am trying to simulate a 100 kHz FitzHugh-Nagumo oscillator in OrCAD Pspice capture (this paper gives the motivation for the configuration, but is for a 180 Hz oscillator, https://ieeexplore.ieee.org/...
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3answers
74 views

Does Crystal/Oscillators package matter?

I design a lot of PCBs that uses microcontrollers with external clocks. For some reason a lot of the example designs always tend to use the big generic HC-49 package. Even factory made modules that I ...
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3answers
95 views

Which components can be measured while soldered on a PCB board already?

I am assembling nonlinear oscillators on PCB boards for applied math research [Colpitts (100 kHz, 3 V_pp), FitzHugh-Nagumo (100 kHz, 15 V_pp)]. I am working with some other people that want to do ODE ...
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1answer
94 views

Why is my LC circuit resonant frequency way off?

I'm very new to oscillators but very keen to learn more so I connected this very simple circuit: where the voltage source is my signal generators and I have an oscilloscope connected across the ...
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2answers
121 views

Can somebody please explain the antenna and mixer stage of this AM superheterodyne receiver?

This is from an Elenco AM/FM superheterodyne radio receiver kit. The shown area is the AM antenna and mixer stage. The wire leading from the top right corner is Vcc. Q7 simultaneously oscillates ...
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1answer
47 views

How to calculate the resonance frequency of this oscillator?

I created the following square wave oscillator in LTspice, which works fine. But I'm not sure how to choose the values of the components. I manually adjusted the values of C1, C2 and L1 until I got a ...
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1answer
114 views

What is this NOR feedback loop in the AGC Cross Point Generator II?

This feedback loop looks similar to a LFSR, however there are no registers present. It looks to be some kind of oscillator. There seem to be three inputs to this component, ...
0
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1answer
22 views

Analysis of 3 Stage CS Ring Oscillator

I am new to the world of oscillators, so take it easy on me. I have been attempting to analyze the following common source ring oscillator: However, I am having some trouble here. So based on my ...
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3answers
104 views

Asymetrical square wave or rectangle wave amp op

I need to find a circuit that produces a rectangle wave(picture below) and that only uses one capacitor(0.01 micro Farad), 1 amp op with a single supply line(Vsat+ = +10V and Vsat- = 0) and how ever ...
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0answers
75 views

Understanding an oscillator circuit

I'm trying to build a driver circuit for an ultrasonic transducer for fog making. The circuit is required to generate a 1.6 MHz signal to drive the ultrasonic transducer. I have found a circuit which ...
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6answers
2k views

Why do we get only one frequency as output in oscillators?

I am just into oscillators where I learned \$AB=1\$ for sustaining oscillations in positive feedback. Since \$A\$ and \$B\$ are both frequency-dependent, \$AB=1\$ is true only for a particular ...
0
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1answer
62 views

Connecting transmitter coil to the oscillator

Hi guys i have two problems. 1.Where to connect the transmitter coil to the oscillator part? 2.How to make the output of the oscillator stronger? because someone told me that the output coming from ...
16
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2answers
2k views

Why the prevelance of mechanical oscillators in electronic circuits?

The clock sources in modern electronics seem to come invariably from quartz and MEMS oscillators, both of which generate vibrations mechanically. The amplitude and frequency of the vibration are ...
0
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1answer
47 views

Crystal Oscillator Power

In the following circuit: taken from: https://circuitdigest.com/tutorial/quartz-crystal-oscillator How is the crystal powered to begin oscillation? I understand the amplifier is required to prevent ...
0
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1answer
42 views

Electronicaly switching parallel LC circuit components

Let's say I have mentioned circuit and I want to be able enable/disable one of the 1uF capacitors to change the frequency of the LC circuit. I would like to do this electronically with a micro-...
0
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1answer
53 views

PIC micro controller oscillator frequency

The internal clock (Q1–Q4) of PIC Micro controller runs at a quarter of the oscillator frequency (FOSC/4). My question is if i divide the frequency with 4 Then the timer period of each clock pulse ...
0
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1answer
49 views

Measuring direction of current to determine moisture is present

I am building a moisture sensor with an AC current to prevent electrolysis. The AC will be generated with a simple schmitt trigger oscillator with the midpoint reference set at 2.5V. Water would ...
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2answers
64 views

Differences between Colpitts oscillator circuit designs

What are the differences between this colpitts oscillator design? I need to build one for the transmitter of my wireless energy circuit for my project in our school, but I don't know what to use.
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0answers
63 views

How could using an op-amp on the output increase the frequency of an electronic oscillator?

I am trying to send an input from a 5 MHz Colpitt oscillator through an op-amp configured as a 10x gain buffer. We are connecting the collector node of a common base Colpitts electronic oscillator (...
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1answer
53 views

What's the source of this noise in my Arduino oscillator?

I've been experimenting with techniques to rapidly switch on and off the digital output pins in an Arduino. This is the code I use: ...
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0answers
51 views

Schmitt trigger oscillators interfere with eachother (74HC14)

I am using a single 74HC14 (hex schmitt trigger) to implement three oscillators. I now have a test build ready and encounter problems. See schematic, it shows component values. Also proper 5V power ...
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2answers
57 views

3.3V Oscillator AC couple to 1.5 Vp-p input

I'm using MICRF220 (origin from MICREL, now Microchip, Sadly, I can't find a suitable place to ask my question. It seems Microchip has not a suitable forum for this chip yet!!!) It can receive ...
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2answers
94 views

Need help understanding an electronic oscillator (Schmitt trigger + capacitor) [duplicate]

When we use this circuit, the LED blinks. I know an inverter transforms high to low voltage and low to high voltage, but here the voltage source is connected to the inverter all the time so the ...
0
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3answers
92 views

Wien bridge slowly decaying oscillator

I want to build a resonator that slowly (~3 seconds) decays without a stable oscillation. I've tried using a simple RLC circuit without luck - I've got ~1-2ms decay time at maximum; so, I've turned my ...
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0answers
36 views

Simple oscillator design not working when implemented

I thought this would be a quick build, but maybe there is something wrong with the design. Even though no waveform occurs, the MOSFET gets very hot. f = 1/(2π√[C(L1+L2)]) An n-channel 2N7000 MOSFET ...
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0answers
32 views

Simplest schmitt trigger with fewest part count for microcontroller

I own several AT89C4051 microcontrollers and I'm currently trying to read signature bytes of the micros that I probably broke (by applying 7.2V to the VCC pin before noticing the 5V regulator became a ...
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2answers
76 views

Help with an oscillator implementation

I want to simulate a simplistic "Van der Pol oscillator" in a circuit simulator such as LTspice or circuitLab. The only circuit I found is the following: But this requires negative resistance ...
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4answers
110 views

What happens if the frequency of the receiver osc does not match (exactly) the carrier frequency?

I thinking about FM and AM. Theoretically the carrier frequency is perfectly match the demodulation frequency. But what happens if there is a mismatch? I think using AM the frequency of the base-band ...
0
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0answers
42 views

Minimalist high speed 8051 microcontroller testing circuit on breadboard

I'm trying to come up with a circuit using the least number of parts possible to build on a breadboard that tests the basic functionality of a microcontroller, specifically the AT89LP4052 ...
2
votes
1answer
103 views

Separate GND-plane for microcontroller crystal resonator

1.  Background info I'm designing a board for an STM32F767ZI microcontroller. This microcontroller has a primary oscillator for the SYSCLK (overall system ...
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0answers
59 views

What would be an appropriate oscillator crystal for an STM32F042C6T6 given the following circuit?

I am building the circuit for a CAN interface for Linux following the schematics for the CANalyze hardware. I have sourced every component for the build except the crystal oscillator. The schematic ...
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2answers
54 views

Calculating the oscillator frequency

I am trying to calculate the frequency of the internal oscillator, in order to go through the design procedure listed in the datasheet. The problem is that it gives me answers that contradict the ...
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3answers
1k views

Difference between internal and external oscillator for a microcontroller?

I am a beginner with respect to microcontrollers, so I just want to ask is there two option for choosing the frequency of the microcontroller: to be internal or external? If there is internal ...