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

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49 views

How to balance between frequency and duty cycle in this circuit?

I have this astable circuit that generate square waves with independent control of frequency and duty cycle: For this circuit: $$t_H=0.759\,C\,(R_f+R_y)$$ $$t_L=0.759\,C\,R_x$$ $$period = ...
6
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2answers
99 views

How to improve the full bridge / half bridge start up time?

I am trying to find out a way to improve the rise /start up time of a series LC circuit placed in a full bridge (or half bridge) circuit. Here is a simplified schematic. The circuit works very well, ...
3
votes
1answer
31 views

LC Oscillator Gain Compression

I am designing an LC Colpits common base Oscillator for the FM broadcast band. The project is going to be extremely low radiated power as I will only be using it in my car. I am currently using this ...
0
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2answers
49 views

Output impedance of an oscillator

I'm using a 27MHz oscillator and trying to measure its voltage level and waveform with oscilloscope. But I have no idea how to match the impedance of oscillator and oscilloscope, since the data sheet ...
1
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1answer
43 views

Unwanted oscillations and distortions in buck converter

I've tried today to design a very simple and crude 26V to ~12V buck converter. But after testing it in LTspice I've got some weird and unexplained oscillations and distortions. The oscillations ...
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0answers
56 views

How does the Wien Bridge Oscillator circuit work

I've built a Wien Bridge Oscillator circuit and used it to generate low-distortion sine waves. But I don't understand how this circuit work. I've read through many resources but yet, I can't ...
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0answers
39 views

Initial voltage of a oscillator

I'm currently trying to test the initial voltage of the oscillator below. The test circuit in the datasheet only gives me Rt (2.7k) and Ct (.01uF) which I have to gnd and 20v to vin. I'm not getting ...
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1answer
52 views

Wien bridge oscillator circuit doesn't work

I've connected the circuit of Fig 3.4.6 in this link which is shown below: Here is the circuit that I've connected: Where in my circuit: R3 = 100 kOhm R4 = 47 kOhm R1 = R2 = 5.1 kOhm C1 = C2 ...
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3answers
82 views

What can cause an oscillator output voltage to go higher than expected?

I am currently testing a 50MHz 3.3V CMOS oscillator in my circuit, which is connected to two pins/loads - MCU pin and Ethernet PHY pin. The oscillator is rated for 15pF output load, which I could be ...
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1answer
55 views

Minimum voltage for a RC Oscillator

I am trying to run an RC oscillator using a 2n3904 the circuit looks like the following. You can see the live circuit here. Simulation I want to run it at 0-5v but I am not getting the result, I ...
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0answers
27 views

Error in 'Multisim' when connecting two op amps in cascade

I've connected the circuit below (wien bridge oscillator) and simulated it using Multisim: The results were expected: a sinusoidal wave of 1.2 Vp-p. I wanted to amplify this resulting signal, so I ...
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1answer
55 views

How can I build a dual potentiometer?

I am about to build a wien bridge oscillator circuit which is shown in the figure below: However, I need a dual potentiometer to do so, because the resistors VR1a and VR1b must have the same value ...
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0answers
61 views

How exactly does a transistor work in an oscillator?

I've spent a lot of time studying the basic function of bipolar and JFET transistors but then find myself still struggling to understand how they work in the context of relatively simple networks such ...
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2answers
33 views

Best circuit to get an array of signals with the same frequency and edge-synchronizable to a reference but individually controllable duty-cycles?

I am looking to build a circuit to control five different FET drivers individually. The input signal would be a single shot from a function generator, which should produce five output signals, with ...
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2answers
37 views

Application of LC circuit(tank circuit)

I have read that tank circuit is used for radio tuning. When we tune a radio we change the variable capacitor, hence the value of LC changes. This would result in a change in the resonance frequency. ...
0
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1answer
79 views

How to drive power MOSFET at 1 MHz

As part of a radio transmitter design, a square wave oscillator has to drive a power mosfet. Given the gate capacitance and the frequency, the maximum current should be around 50mA. The power mosfet ...
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0answers
57 views

clock frequency too high

I have wired up the clock generator below. However, when I attempt to measure the frequency with an oscilloscope, it is far too high and quite unstable. The measured frequency ranges from 12-50 ...
1
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1answer
60 views

555 VCO Circuit - Speaker to VCC?

Hello! I have a simple question concerning this circuit I have built: It is a 555 Voltage Controlled Oscillator I have built as a foundation for my signal generator circuit. The circuit works ...
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1answer
46 views

Can I use a Quarz Oszilator instead of a Standard quartz?

I want to complete this tutorial on burning a bootloader onto a atmega328. There a Standard quartz is used, but called a Quarz oszilator. Now I bought this Oszilator. Can I use the oszilator as well ...
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2answers
75 views

Need approval of transformer driver design

I designed a circuit from several ideas I saw before and I'm a bit too impatient to build the thing myself. (http://imgur.com/KD97NuJ) Basically, it's a two-transistor oscillator combined with an ...
0
votes
1answer
54 views

hse external oscilator on stm32f030

According to ST AN2867 Oscillator design guide for STM32, the oscillator circuit requires a Rext resistor There are minimal boards with stm32f030f4p6 on ebay, aliexpress... It looks that rext is ...
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1answer
95 views

Oscillator will not start up reliably

I have designed a PCB using a PIC18F6520 and a 32MHz crystal. Using a breadboard with a PIC16F877A, my code works great. But when I load a simple LED blinking program onto my PCB, the LED flickers ...
3
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2answers
85 views

LC Oscillator Circuit Analysis

I've found this schematic of a LC sine wave producing circuit online, and I was trying to figure out how it works (particuarly the feedback cycle). Can someone tell me if this is right? I think I've ...
0
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1answer
86 views

Effect of Small and Large Signal Transconductance on the Colpitts Oscillator

I've been following Ron Quan's book: Build Your Own Transistor Radios and I've come to the section where Ron is analyzing the oscillator circuits used in his designs. In particular, he discusses the ...
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1answer
86 views

Long lived LED indicator

I want to have an extremely long-lived (at least one year) blinking LED with a single battery, like one 9V. Think like the battery indicator light in a smoke detector. The LED doesn't matter to me. ...
3
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1answer
131 views

How does this oscillator work?

I am trying to understand the following oscillator from a Cyclone 40 transceiver (http://www.4sqrp.com/cyclone.php). Here the the VFO (in the actual device, the inductor has a bolt through it to tune ...
3
votes
1answer
52 views

What kind of oscillator is used for CMOS CPU clocks?

Do they usually have a mono/bi-stable multivibrator that is activated a schmidt trigger when the computer is powered up? Or do they use ring oscillators? Or perhaps crystal oscillators.
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0answers
81 views

Colpitt's Oscillator: How do I set the output peak to peak voltage of the oscillations?

Good day, we are currently working on a VCO project that uses a transistor based Colpitt's Oscillator. We were asked to select a frequency of operation where we selected 89.1MHz as its center ...
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2answers
439 views

Using CMOS Schmitt trigger inverters in quartz crystal oscillator circuit

In all sources I've seen about quartz crystal oscillators using CMOS inverters there's a note like this: But why Schmitt inverter is needed? Won't classic 74HC04 work?
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2answers
124 views

Common Emitter Colpitts oscillator

Good day, we were tasked to design a transistor based RF oscillator to be used as a VCO for our design experiment. In the picture shown below I have seen many tutorials on how to set the L1, C2, C3 ...
8
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1answer
269 views

Does this oscillator have a name?

I found this oscillator schematic and I hope to find more information about it.
0
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3answers
69 views

Where are the external oscillator pins on PIC12LF1572

I have searched the whole datasheet, but couldn't find where are the OSC1 and OSC2 pins are. I've found the CLKOUT (which is CMOS output) on RA4 and CLKIN (which is TTL input) on RA5. But I need the ...
3
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2answers
79 views

Atmega8 - Max output frequency seems to be devide by 4

I'm a little bit confuse, and hope that someone here can point me out what I'm missing... I'm using an Atmega8-16PU, Flashed the fuse with : ...
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2answers
132 views

Setting up Internal Oscillator with PIC16F1829

I just started working with PIC microcontrollers and I am currently using MPLAB X IDE with a PIC KIT 3. I've been trying to get a simple LED blink code to run on a PIC16F1829 using the internal ...
3
votes
1answer
84 views

Does thhis crystal circuit works?

I need a tiny oscillator circuit for testing an application. Now I haven't much experience in creating oscillators so I would like to use this Collpits-circuit: I only need the carrier wave so I ...
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votes
5answers
668 views

Is this phase shift oscillator design correct?

I found this design on the internet. It's a 180 degree phase shift oscillator. Actually, it is a 203 degree phase shift oscillator. Because the frequency is 6.5 kHz and the capacitive impedance is ...
4
votes
3answers
291 views

How to overcome transistor heat in slayer exciter?

I build this circuit and it works but I have two problems. The major problem is that the transistor becomes very hot quickly. I burnt my transistor due to excessive heat. How can I get rid of the very ...
1
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1answer
118 views

Need Help In Creating and Debugging a 8Mhz CLK Circuit

I want to create a CLK generator circuit that will work at 8Mhz. I'm following this design (from http://www.electronics-tutorials.ws/oscillator/crystal.html): My crystal is 8Mhz HC49/US, with 20pF ...
0
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1answer
120 views

tunable Wave form generator design with op-amps Multisim

I need to simulate a waveform generator using Multisim. I used the design in this Link. the frequency is 1KHz. It works fine but I need some modifications: 1. I need the peak to peak voltage(Vpp) to ...
0
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1answer
73 views

Splitting AC voltage based on phase

Is it possible to separate the positive and negative portions of an AC voltage wave into two separate lines, where one line has the positive voltage portion (and is neutral when the source is ...
1
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2answers
120 views

Royer Oscillator

Hello everyone and thanks for your time reading this. I recently switch my oscillator circuit over to a digital based version. With this topology I can monitor source currents on each RF MOSFETs ...
0
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2answers
116 views

What are the differences between function generator and oscillator? (Specific design)

I design the attached circuit: 75 MHz Sine wave that connected to R and C in parallel: In the output, the amplitude of the sine wave is changing according to the C, more capacitance smaller ...
0
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1answer
67 views

Testing voltage continuity using a beeper?

I have a 48v rail and i wish to plug it into an audible oscillator to check for continuity when i am rattling the system under duress. What is the simplest circuit that i can plug into 48v to hear the ...
5
votes
1answer
124 views

Using crystal in LTspice (where to get values for RCL)?

I'd like to simulate a schematic in LTspice driven by a crystal. An capacitor representing the crytal (as a resonant circuit) however it needs some specific values. Is there a table of common values ...
0
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1answer
42 views

How to connect current circuit?

First of all, sorry for trivial question. While googling came across the current circuit, but I'm puzzled how to connect this circuits: There is 4.5V out put where to connect this, and the whole ...
3
votes
0answers
130 views

pic32 maximum external frequency while running from internal 8MHz RC oscillator

I am completely new to PICs and I have never worked with a part as complex as this. In particular, I'm wondering if it is possible to generate a reference clock (REFCLKO in the datasheet) at 11.2896 ...
6
votes
1answer
130 views

JFET - Ceramic Resonator - Oscillator Phenomonom going in and out of oscillation

An oscillator using a ceramic resonator is going in and out of oscillation. I have an oscillator circuit with a peculiar phenomonon. The oscillator does work (mostly). The “crystal” I am ...
2
votes
1answer
123 views

How to build 200 Khz oscillator using Wien bridge?

I've the following circuit for generating sine wave. As I'm supposed to make sine wave within 1 kHZ - 200 kHz, I chose wein bridge oscillator circuit. However, I'm not able to increase the ...
4
votes
1answer
111 views

Transistor Based Wien Bridge Oscillator

I've been studying the schematic for this RLC Bridge from Heathkit (IB-5281). The full pdf can be found here (search for the part number): http://www.vintage-radio.info/heathkit. The circuit ...
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4answers
56 views

Barkhausen condition on a Wien oscillator

Consider the Wien oscillator: We can determinate the operational amplifier gain defined as: $$A(s)=\frac{\bar{V_o}}{\bar{V_a}}$$ and the gain from the feedback network: ...