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

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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
63 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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26 views

How would I create an oscillator for a rectified flyback? [on hold]

I created a spark gap of about 2 inches from a flyback transformer. The power source used is 19v and 2.15 amps of DC. http://youtu.be/cd3LdRC9njg *I changed the capacitor to .1µf because with a ...
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1answer
75 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
83 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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55 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
60 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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44 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 ...
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25 views

Phase-shift oscillator (high pass configuration) why only 2 resistors to ground?

Today I built another phase-shift oscillator (you can see my full notes here). The circuit is based on those I've found online, and uses the capacitors in a high-pass configuration: The circuit ...
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21 views

phase-shift oscillator design decisions

I've been learning about phase-shift oscillators and put together this design: I built it and it seems to work pretty well, you can see the exact values I used, and design here: [1]. But the design ...
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35 views

Understanding astable multivibrators

I've been trying to understand the astable multivibrator shown above. Wikipedia has a pretty good description. But I've tried to write it up on my blog in my own words here: ...
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1answer
136 views

Trying to understand this oscillator… there's no emitter grounding or bias

I dissected and drew up this oscillator circuit from a cassette machine the other night. It's purpose is for biasing the tape. I'm curious though as to how this oscillator functions since the base is ...
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1answer
36 views

Attenuated Lower Envelope from Colpits Oscillator

Could someone explain to me why the output of this oscillator is the way it is? With a DC input of 6V (no small signal), I get an oscillation between -2V and 7V, which was unexpected. Is this due ...
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29 views

Amplify an electret microphone and feed the amplified signal through a piezoelectric disc?

I’m a student and Im trying to use an electret microphone to pick up an audio signal which is then reproduced by a piezoelectric disc as a part of an experiment with sound perception in spaces and ...
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1answer
71 views

PnP NpN transistor circuit, Were would the mic jack go?

I know the circuit says to put the mic jack parallel to the speaker, but im not exactly sure were to put it. Also, could I use another speaker as the mic? This is the pnp npn circuit I found on the ...
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1answer
66 views

Oscillator with CMOS inverter - calculate elements

I am trying to make 125 KHz oscillator based on CMOS inverter and feedback circuit consisting of Pi C-L-C section, as shown below. Since I need sine wave I will ommit the second inverter. Before ...
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2answers
72 views

Replacing Crystal Oscillator with DDS.

In a circuit like this, can the crystal oscillator be replaced with a DDS such as a AD9850? If so can it just be dropped in or would other components have to be changed? Second question, how ...
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2answers
94 views

Why doesn't this oscillator oscillate

According to the solution, it says it's because the phase shift is wrong. The gain network is non-inverting, so I assume that means that the LC feedback network was not 0 degrees for that particular ...
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2answers
250 views

Does this simple RF transmitter circuit actually work?

I've come across this circuit a few times while searching for simple transmitter circuits, and decided to try it. According to this site, it should be transmitting at around 90Mhz. ...
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1answer
79 views

I need helping understanding this VCO circuit

The two circuits of interest are described in pages 12-14 of Texas Instruments' Application Note 263, Sine Wave Generation Techniques PDF WARNING I'm primarily concerned about the circuit in Fig. 15, ...
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3answers
90 views

Unexpected resistor for oscillator

Please see these two part of this board : In your opinion, What's the usage of the R32 resistor? also in the AN2867 aplication note has been mentioned: Then we have to put a resistor to limit ...
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1answer
44 views

Inverting effect of resistance in an RC circuit

I have a question on basic electronics. I'm looking at a very simple CMOS RC Circuit around a Schmitt Inverter which creates square waves. Something like this. simulate this circuit – ...
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2answers
108 views

What's the frequency v power relationship of an oscillator + transmitter?

I'm starting with the assumption that a higher frequency EM wave is more energetic than a lower frequency one and thus requires more energy (and thus more power) to transmit. In my naive model of a ...
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1answer
90 views

crystal oscillator output

I have seen the crystal oscillator output in the oscilloscope and it looks something similar to a sine wave (at least nothing similar to a square wave and with a hard to calculate duty cycle)! So ...
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166 views

Simple Oscillator Designs

I want to be able to create simple oscillator circuits for clocking in digital circuits and am wondering what is the most simple design people know of? I could use a simple ring oscillator which is ...
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1answer
300 views

Crystal Oscillator not giving correct frequency

I have a 48MHz Crystal Oscillator (see here) that I am using as a clock for my microcontroller (EFM32GG332F1024). Looking at the datasheet for this crystal it seemed to me that the load capacitance is ...
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79 views

Troubleshooting circuit in make Electronics Book (Experiment 8) [closed]

I created the same circuit as in Experiment 8 of make Electronics book but cannot get it to work in the same way as described in the experiment. When I connect the circuit to the power source and ...
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1answer
48 views

analysis square waves oscillator: how do I calculate the values?

Which are the Vc (V+) and V-, I's and Vout values in these circuits? The node i's and the Vc and Ic?
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1answer
43 views

Error: Model in Pspice is undefined

When I simulate the circuit below in Pspice, the output info says: model J2n5485 used by Q2N5485 is undefined. But I have defined the model in the code. I need to ...
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2answers
110 views

Why does the tank circuit of Coplitts oscillator produce 180 phase shift?

http://www.circuitstoday.com/colpitts-oscillator I would like to understand how Coplitts oscillator works. This link says that the tank circuit of Coplitts oscillator produces 180 degrees phase ...
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1answer
85 views

PIC18 not working when wiring 30pf capacitors of cristal resonator to ground

I'm using pic18 with external oscillator 16MHZ 16M HZ HC-49S Crystal Oscillator with two 30PF capacitors configuration OSC = HS using breadboard, when wiring the ...
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2answers
145 views

Need help understanding simple oscillator circuit

I know this seems like a really basic question, but bear with me. The following circuit diagram is given by one of my old electronics kits: simulate this circuit – Schematic created using ...
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1answer
115 views

Transistor amplifier circuit for triangular wave

I've made triangular wave oscilator as shown in Fig. 1 and it works perfectly at frequancy 10 kHz with peak voltage +3 Volt to -3 Volt. I intend to generate SPWM. But when I feed this circuit to ...
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1answer
94 views

Value for feedback resistor in pierce crystal oscillator configuration

This question is partially an "understanding english" question and partially and "understanding the pierce oscillator configuration" question. Backstory I'm currently looking at using a Freescale ...
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1answer
107 views

How to design a 500 khz sine wave generator? [closed]

I need to design a 500 khz sine wave generator. Could anyone help?
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1answer
70 views

How could this GPIO-controlled LED status blinker be improved?

I'm building a simple circuit to drive an LED status indicator in a project built around a RPi. The circuit takes its power from the same source as the RPi and is connected to one of the RPi GPIO ...
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2answers
74 views

can LC tank circuit alone produce oscillations? [closed]

Circuit below is the hartely oscillator circuit, I simulated it in multisim to know how exactly oscillations occurs, while doing so I just seperated tank circuit (from tansistor base and collector ...
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74 views

Oscilllator model in multisim

What's wrong with this schematic? Multisim doesn't generate oscillation. Also I changed R3=1000, R3=500 but all the same.
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1answer
81 views

Why does this circuit oscillate and produce sound?

I've connected an 8-ohm speaker in series with coil. When I apply 5 volts / 500 mA to the combination (coil and speaker), I heard a very high frequency sound (something like whistling). The coil is ...
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39 views

Can I replace crystal input with mems oscillator

I am designing a device that uses a real time clock (RTC) from ABRACON. AB1805-T3. RTC Datasheet: http://www.mouser.com/ds/2/3/AB18XX-30381.pdf The device has the option to either select an internal ...
3
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1answer
173 views

PIC16F628A Blinking LED

I was setting up a PIC16F628A for a simple Hello World program (blinking LED) and somewhere in the process, I have failed. The LED stays lit at the specified pin and does not "blink". I am using the ...
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1answer
56 views

CMOS vs LVDS oscillator

I am trying to select a 160MHz clock oscillator for my FPGA. The least expensive I found was either LVDS or LVPECL type for this frequency. I used a CMOS type before, so the output of the oscillator ...
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2answers
238 views

Use 555 for additional 40KHz PWM in Arduino

I need to transmit infra red signals using IR LED from my Arduino device. The IR signals consist of PWM 40 kHz periods and "silence" periods of various length (typical IR remote signals). I know ...
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43 views

Why Inverter with feedback oscillates ? [duplicate]

Phase difference between input and output for this circuit is 180 degree. That means Barkhausen criteria is not satisfied,still circuit generates a oscillating signal. Why ?
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2answers
71 views

Question about CMOS Inverter Oscillator

Using CMOS inverter with crystal and cpacitors, we can make a oscillator. And i find many docs mention the method 'negative resistance'. But, they are not all the same. The method from TI's doc: Use ...
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84 views

How can I use the OSC2 pin as normal IO on a pic32mx150f128b?

Everything else works well, the CPU runs at 40 MHz, UART works, GPIO works; the OSC1 pin works as GPIO as well. But I cannot use OSC2 as GPIO. I am using the Fast RC oscillator with divide-by-N and ...
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45 views

Fixed Frequency Synthesis with PLL

I'd like to design a downconverter with a fixed local oscillator frequency ~2GHz with fairly good stability. I understand that the best way to do this is a PLL with a fixed crystal oscillator and a ...
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69 views

Feed Raspberry Pi camera module with external clock signal

I want to frame synchronize multiple Raspberry Pi camera modules - I guess I can do this by feeding all the modules with a single external clock signal. The thing is being discussed in this post. The ...
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78 views

Working of RC Phase shift Oscillator?

Figure show a RC phase shift oscillator using Op-Amp with gain 5(Vo/Vi). My assumption : Circuit is generating a sine wave with a peak to peak voltage of 10v. Consider positive maximum point (+5V) ...
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188 views

Problem in wien bridge oscillator

I have put up a circuit for Wien bridge oscillator using 741 op amp, with R= 390 ohm and C = 2.2nF, for operation around 200 khz ( gain is 4). However, it did not work so I switched the resistor in ...