Questions tagged [function-generator]

A function generator usually refers to a piece of test equipment that generates a variety of waveforms over a range of frequencies. A typical unit may generate sine, square and triangle waves at a frequency up to around 20MHz, they tend to be less often used at higher RF frequencies.

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17
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6answers
4k views

Hobby function generators

I am a physicist with a limited knowledge of electronic. I usually study my problems extensively on Internet before asking for a help. This means that here I will present both the questions and ...
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4answers
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Analog function generator ICs? [closed]

Does anyone know of any old-school function generator ICs (similar to the ICL8038 or XR2206) that are still on the market? (i.e. not obsolete / NFFD - I'm not interested in scouring the globe for old ...
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567 views

White and Pink Noise Generator Circuit - Cryptic AC Analysis

The “Electronic Devices and Circuit Theory” book (by Boylestad, Nashelsky) gives a brief description of a random noise generator circuit at the end of “BJT AC Analysis” chapter. (Btw, exactly the same ...
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Can you use Oscilloscope probes for a Function Generator?

I just bought a cheap function generator and have no test leads for it. I do have 2 pairs of oscilloscope probes with a 1X-10X switch on them. I am curious to know if I will get the same results with ...
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5answers
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Why do TTL pulse generators generate an asymmetrical square wave (unlike CMOS)?

I've read that the asymmetrical (about 1/3 mark-to-space) output waveform is due to input gate characteristics of a TTL inverter, but I want to know more about which characteristics of the TTL input ...
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1answer
12k views

Internal resistance of Function Generator

I'm using a function generator that has a 50ohm internal resistance. Does this affect any circuit that I may connect it to and if so, how would it affect the results?
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5answers
11k views

Simple function generator using microcontroller

Is it possible to make a function generator with a microcontroller (PIC18F4550 OR PICAXE20X2)? I am thinking that for generating square waves it can be enough to make a pin output high and low on ...
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3answers
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Can I use a subwoofer as a linear actuator?

I need an actuator with a few mm of travel and it has to be very responsive to a very low frequency (DC 10 Hz) sine wave generated by a function generator. I'm thinking of getting a cheap subwoofer ...
4
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1answer
344 views

Locked-Sync Sine Generator Covers Three Decades with Low Distortion

I am working on my first project in analog/board design, and although I know a decent amount of theory in electronics, I am lacking in practical experience. I need an exact sine wave generator, and ...
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2answers
16k views

Should the output impedance of a function generator be high or low?

As we know, \$R_{load}\$ should be greater than \$R_s\$ on a function generator to avoid loading effect. Does it mean that the output impedance of the function generator should be lower?
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1answer
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What kind of cable does a function generator use?

I picked up an Agilent 33120A function generator used (yay!) and I need to buy the cable that attaches the output to the circuit. Problem is, I'm not sure what kind of cable it is. So, I guess I ...
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3answers
553 views

Do function generators produce AC signals in the sense we know?

When I examine function generators, there are a wide range of products. I see products between 7 USD and 600 USD. If they can do the same job, why is there so much difference in price? I can't make ...
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2answers
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Square wave to sawtooth wave using two BJT

I have two circuits that are supposed to be square wave to sawtooth wave converters: Both circuits receive a positive square wave as their input and generate a positive sawtooth as their output. Do ...
3
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1answer
411 views

Need help setting up sweep function for signal generator

I recently bought a signal generator from Amazon. The model I got was the UDB1205s but I believe my question applies to any of the manufacturer's signal generator in the UDB120x series. A similar ...
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2answers
269 views

How to Identify a Power Receptacle

The Wavetek 144 HF frequency generator has an unusual power receptacle that I cannot identify. The link references the manual, which does not name the part. I'm not sure it isn't proprietary. Here is ...
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4answers
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High speed (>30KHz) 10-bit PWM generator

I'm looking for a way to generate a high speed PWM signal into a high impedance input gate driver IC. This would be used to replace a lab bench waveform generator. Preferably I would use something ...
3
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2answers
1k views

Design a simple circuit to generate variable +5V to -5V signals

I want to design a simple circuit that takes 12V from a battery and generates two signals each of range -5V to +5V. These signals are input to a 2-Channel ADC. I want to be able to change the voltage ...
3
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1answer
2k views

LM348 replacable by LM358

I want to give SMD soldering a try and therefore I was looking for some useful circuit (no LED-blink-crap) I could build more or less easily. So I found a nice DIY function generator here. It uses ...
3
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1answer
1k views

What is output amplitude of Direct Digital Sythesizers as AD9850?

By looking at AD9850 DDS or other similar parts made by Analog Devices Company it is obvious that the output signal amplitude changes by frequency. This can be shown as x= pi* fout / fClock and ...
3
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2answers
2k views

Simple function generator: is current-limiting/short circuit protection/impedance matching necessary?

I have designed a function generator with the intent to provide test signals to a microcontroller or ADC of some other device. However, I may forget that a year down the line and plug it into some ...
3
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3answers
348 views

Do analog circuits exist that are essentially mathematical functions in DC?

I am curious if a class of analog circuits exist that would take say a 0-5 V input signal and output a mathematical function like a sine function mapping 0-5 V to 0-2pi, or a log, exponent, polynomial?...
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1answer
819 views

Sine wave distortion in simple op-amp circuit- bypass capacitor?

I've built a simple unity-gain buffer op-amp circuit from the UCSB lab here, with a 12V power supply and a 1V, 1 kHz input sine wave. simulate this circuit – Schematic created using CircuitLab ...
3
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1answer
194 views

Setting up the “Basic Bipolar Output Operation” connection on a DAC08 chip

I have an 8-bit waveform description coming from an FPGA into the DAC, and I want to read the analog output on an oscilloscope. I figured I should implement this setup found in page 11 of the data ...
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1answer
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How to apply the Barkhausen criterion in order to know if a system will oscillate?

How to analyze or apply the Barkhausen criterion for oscillation of the astable multivibrator below? The criterion talks about the magnitude of the products in a loop must be equal to 1 (ideally) The ...
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4answers
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What is causing this Op-Amp Distortion

I am new to analog electronics and I am still learning about op amps. I am driving an 8ohm 15 watt speaker with just an op amp and my phone. What I do not understand is that I have a dual supply, 10V ...
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2answers
542 views

What is a best way to get a 25% duty cycle square wave (5 V, 1 MHz) on a board?

I am trying to get two off-phase 25% duty cycle square waves(1MHz) to control a full bridge circuit. Update:Sorry for the confusion here, what I mean was to have 2 square wave signals, and introduce ...
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4answers
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Generating a sine wave over a big frequency range

I want to build a circuit that can generate sine waves at frequencies controlled by a computer or a microcontroller. I would like to go as low as 0.01 Hz (down to 0.05 Hz would probably be acceptable) ...
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2answers
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Error caused by Scope or Function Generator?

This question may not be valid, please excuse my ignorance. I am having difficulty measuring a decent square wave at 500kHZ. The image below shows a 4 volt CMOS output with a frequency of 500kHz ...
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2answers
165 views

What switch would replace a series of 6 pins linked by jumpers?

I've bought a small electronics kit - a function generator which produces a 1kHz signal in various waveshapes - square, sine, triangle and integrator. It's a basic kit on a single PCB (555 timer based)...
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3answers
923 views

Active signal generator IC for 100kHz [closed]

I am trying to get an IC to generate a 100kHz sinusoidal waveform for my circuit. However when I google, all I can find are retired products which make me very hard to find (I stay in Singapore) so ...
2
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1answer
87 views

Noob Measurement Mystery

I am taking up electronics and bought some used test equipment. I have been measuring anything and everything, sometimes with unexpected results. Above is one of those cases. The function generator ...
2
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1answer
6k views

Oscilloscope/Function Generator with GnuRadio (using very cheap hardware)

I was just getting started with RF signal processing, and I was very interested in being able to make an oscilloscope and function generator work in real time with python. Essentially, I would like ...
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2answers
359 views

True Random Number Generator by using avalanche breakdown

I am trying to build a TRNG using avalanche breakdown for randomness. I am developing a circuit as looks like this.(https://web.jfet.org/images/rng-circuit.gif) Before I complete the circuit i ...
2
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2answers
357 views

Flashing “GATE” on the Bel Merit FG-150 function generator

What does the flashing in the bottom left corner of the display "GATE" means on this generator? I could not find a manual high and low. I found a discussion on GATE function here but it seems to ...
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1answer
2k views

triangular and square wave generator

the circuit below is a triangular and square wave generator. With the first stage (the integrator) I can generate a triangular wave, and with the second stage (comparator) I can generate a triangular ...
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2answers
4k views

How to drive 1MHz Ultrasonic Transducers

I have 2 ultrasonic transducers (see below picture) facing each other with spacing of 10cm (adjustable). I would like to supply 1 MHz sine wave (from function generator) to one transducer (...
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2answers
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How to control a speaker

We are trying to produce a sound wave with speaker. We also need to be able to control the frequency (we don't have specific numbers, about 50-500Hz). As far as we are concerned we are looking for a ...
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3answers
10k views

Measuring a soundcard output voltage

I have been experimenting with a Soundcard Oscilloscope and I am having some problems understanding what's going on! I have attached a screenshot of my digital scope setup. My hardware setup is simple....
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1answer
466 views

Impedance of BNC vs output impedance of function generator

I'm a bit confused on output impedance of function generator and coaxial cable impedance. Consider a function generator with output impedance of \$50 \Omega\$. Suppose that I connect to it a BNC \$...
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1answer
517 views

Waveform Function Generator - Practical Usage [closed]

I never had any chance yet to play with function generators, but I know what they. What I don't see at this moment is their practical usage in digital electronic. For audio I can see it probably for ...
2
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1answer
406 views

Why did aliasing occur at a frequency before the Nyquist cutoff?

I sampled frequencies of 400, 500, and 600 Hz at a sampling frequency of 1 kHz. My oscilloscope showed aliasing at 400 Hz, nothing at 500Hz, and then a lot of aliasing at I saw some aliasing ...
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3answers
1k views

Function generator to test filter capacitors

I'd like to be able to see the effect that a filtering capacitor has on a voltage source with waves at different frequencies, for learning purposes. I'd like to try to calculate the correct capacitor ...
2
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1answer
452 views

Voltage Divider with low noise?

I'm working with a nano scale motion stage with high precision. To move the stage I supply Sinusoidal wave using (Agilent Keysight) function generator. This F-gen, goes as low as \$20mV_{pp}\$ in ...
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0answers
48 views

Oscilloscope to Function Generator Trigger Delay

Simple question, is it common for there to be a delay between an external trigger out from an oscilloscope to the trigger in of a function generator? Specifically, I have a Rigol 1054Z oscilloscope ...
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0answers
606 views

Amplitude modulator for a sine wave generator

I have a home made, mostly using the design in a magazine article, radio frequency signal generator, and I would like to be able to modulate (AM) the sine wave output, which is up to 8 MHz, with an ...
2
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1answer
506 views

Peculiar noise when observing a square wave

I'm using the following function generator: http://www.farnell.com/datasheets/499058.pdf?_ga=1.129729036.1263433037.1467971694 and a Tektronix TDS 1002B scope for some measurments. Most of the time I ...
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4answers
1k views

Why can we hear the full range of square waves from 1 Hz-20 kHz, but not sine waves of the same frequencies?

I connected the output (50Ω) of a function generator to a 35 watt 5Ω speaker. When I sent square wave signals of 1 Hz-20 kHz to the speaker, my friends and I were able to hear them. But ...
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4answers
10k views

Function generator as a DC power supply

I'm wanting to start my own lab at home so that I can learn things faster than uni teaches (we're not allowed into labs unless we're in our own lab). A friend said that I'd be better off getting a ...
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2answers
5k views

Why does the voltage output of a signal generator changes with its frequency setting?

I connected a signal generator to a 5.1 ohm resistor, which may be too low comparing to the internal resistance of the generator, so I got only several hundreds millivolts amplitude for frequencies ...
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2answers
5k views

Ramp Generator using op amp

I'm searching for a ramp generator circuit which is using only op amps (I guess I need an integrator & differentiator for that). The output should be like in the image below.