27
votes
Accepted
How to check (with DIY methods) if an Inverter returns a Square or a Sine Wave?
I would try a soundcard. Connect a resistive load (eg. light bulb) to the inverter. Wrap a piece of wire around one of the cables leading to the bulb (DO NOT CONNECT DIRECTLY), connect to mic input ...
- 8,741
19
votes
How do you shift a square wave down?
There are several simple options.
Rail-to-rail op-amp
If you have a rail-to-rail op-amp, this can be done using four resistors as follows:
This will divide the signal down to 0-15V which is in the ...
- 62.1k
17
votes
How do I design a circuit to convert a 100 mV and 50 Hz sine wave to a square wave?
The easiest way to do this would be to use a comparator.
Picture taken from linked site
All you have to do is set your Vref level to where you want your square wave to trigger. When the sine wave ...
- 11.7k
16
votes
Why can we hear the full range of square waves from 1 Hz-20 kHz, but not sine waves of the same frequencies?
Most people can't hear sinewaves below about 20 Hz. The fact that you couldn't hear them until they got to 100 Hz is probably due to poor low-frequency response in your amplifier/speaker.
When you ...
- 167k
15
votes
How to check (with DIY methods) if an Inverter returns a Square or a Sine Wave?
One way is to find the difference between peak and average of the half-waves.
Use a diode full wave bridge to rectify the output of the inverter. Put a 1 MΩ resistor across the output of the ...
- 310k
11
votes
Accepted
What is the best way to get a sine wave from a square wave?
Is there any other better way to get a pure sine wave from square wave
without this voltage drop?
Take your square wave and use a phase lock loop to generate a frequency that is maybe 50 times ...
- 426k
11
votes
Why can a square wave (or digital signal) be transmitted directly through wired cable but not wireless?
Due to the sharp edges, a square wave has a wide spectrum with lots of harmonics.
You could send that over the air with an antenna, but:
1- Signal shape will be distorted at the receiver due to ...
- 69.1k
10
votes
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Sine wave to square wave - Schmitt trigger
I would like to suggest that the comparator circuit shown by @hwengmgr could use some small improvements over what was posted.
Improvements include:
Bigger capacitor value to reduce filter effect ...
- 56.6k
10
votes
Accepted
How do you shift a square wave down?
How do you shift a square wave down?
Just an RC will do it: -
If fed with a sine wave (for the convenience of the attached picture), it will reproduce the sine wave at the output but with the DC ...
- 426k
10
votes
Precise square wave generator 32768 Hz
You have basically two choices- buy a crystal and make an oscillator or buy an oscillator. If you buy an oscillator it should meet the specifications on the datasheet and if those match or exceed your ...
- 368k
9
votes
How to shift down a square wave at 0 - 5 V?
One way is what's known as a data slicer. A simple one, as shown below, requires the average value to be near the middle between the two levels. That is true for a square wave.
Since the input ...
- 310k
8
votes
Accepted
How to shift down a square wave at 0 - 5 V?
@Olin's answer is a good one if you can live within the limitations which are:
High voltage supply for the comparator (or special comparator)
Duty cycle of input close to 50%
Some pulses will be ...
- 368k
8
votes
How to check (with DIY methods) if an Inverter returns a Square or a Sine Wave?
With a high fps camera set to manual exposure, a big resistor (>~10k), and a couple of scrap LEDs (not white) back-to-back in parallel you should be able to measure the brightness -- does it change ...
- 2,311
8
votes
What would cause a square wave to become rounded?
What you are seeing are several harmonics of the square wave being attenuated. As you know, a square wave can be represented by an infinite series of sine waves whose frequencies are multiples of the ...
- 2,192
8
votes
How can I explain the unexpected negative voltage in the output signal obtained from half wave rectifier?
The 1N400x type diode has a reverse recovery time (manufacturer dependent) of up to 30 μs and, when your input voltage falls negative, the diode will continue to conduct for up to 30 μs: -
- 426k
8
votes
Rail to rail +12/-12 V square wave generation with microcontroller
Shoot-through current, the problem is that there is a current path through R5 and R6 in series with the two transistors (basically, diodes) whenever the Q2 collector voltage is between +11.4 and -11.4,...
- 15.8k
8
votes
Accepted
Why is my op-amp pulse generator (LF353) delivering way less voltage (±2 V) than the voltage supplies of the amplifier (±15 V)?
I'm aware that something might be wrong with my circuit but I don't
know what that is
A 100 Ω load (R4) will scupper the output signal levels for an LF353: -
The same is true for the LF353-N: -
...
- 426k
7
votes
Accepted
Confusions on FFT of a square-wave in theory and in scope and simulation
Welcome to the real world!
The "mathematically perfect" transform you show at the top, with the "discrete" harmonics is generated assuming that the rise and fall times of the waveform are zero, and ...
- 167k
7
votes
Accepted
Feed a speaker only with positive voltages
The 0-3.3V signal has a 1.65V DC component, and this will effectively be shorted by the speaker. You should not connect the speaker directly to the microcontroller as the speaker presents a very low ...
- 8,634
7
votes
Square wave generator won't work
Your positive feedback attempts to move the non-inverting input above and below ground. This would work with a dual supply system - ie negative rail below ground.
In a single supply system you need ...
- 146k
7
votes
Accepted
Converting a square wave into a sine wave
Is it possible to preserve the amplitude
No, you can't preserve the amplitude because the fundamental sinewave “inside” a square wave is 27.3% higher in peak magnitude (or \$4/\pi\$ in proper terms). ...
- 426k
7
votes
Why can a square wave (or digital signal) be transmitted directly through wired cable but not wireless?
tl; dr: RF needs a carrier, cable can use baseband. Both are band-limited, RF systems using carriers more so.
A perfect square wave has infinite harmonics. A good square wave has a large number of ...
- 48.8k
7
votes
Accepted
Rail to rail +12/-12 V square wave generation with microcontroller
I'll keep it fairly simple. (And it is very similar to hacktastical's approach except that the input isn't DC-blocked and I've tied the input stage's emitters just slightly differently.) Consider the ...
- 76.9k
7
votes
Impedance, square waves, and duty cycle
Technically, yes, because a square wave is a sum of multiple sine waves, in theory infinite amount of sine waves, so since it is not a single sine wave you compare it to, it will present a different ...
- 120k
6
votes
Sine wave to square wave - Schmitt trigger
Take this schematic :
simulate this circuit – Schematic created using CircuitLab
Playing with Ohm's law, you get :
\$R_{3} \times R_{1}\times V_{R}+R_{3} \times R_{2} \times V_{P} = (R_{1} \...
- 3,337
6
votes
Sine wave to square wave - Schmitt trigger
If its a continuous waveform, you can use a DC blocking capacitor and then use some resistors to set the DC common mode point and scale it as well. Then feed it into an LM339 comparator to get your ...
- 590
6
votes
Accepted
Phase shift square wave
Use a 6 bit Johnson counter and drive that with a frequency 12x higher than what you want. The counter will generate 6 equally spaced, phase shifted, divided output square waves.
- 40.6k
6
votes
Scope says 59.9 Hz .. yet I can't measure turntable speed
Try 120Hz. The light varies with amplitude of the voltage and ignores polarity.
- 368k
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