Using Diodes as Clippers or Clampers | Intermediate Electronics

Summary

In this educational video, the presenter explores the concepts of clippers and clampers in electronics, using a simple circuit setup with a waveform generator and oscilloscope. They demonstrate various types of clippers, including negative and positive series clippers, and how they clip the input signal differently. The video also covers biased series clippers and their behavior with DC offsets. Parallel clippers are shown, highlighting the diode's role in determining the load voltage. Finally, a clamper circuit is explained, illustrating how it shifts the entire waveform's voltage. The presenter encourages hands-on learning and refers viewers to a detailed written tutorial by Harold for further understanding.

Takeaways

• 🔬 The tutorial focuses on demonstrating clippers and clampers in electronic circuits.
• 📚 Harold's written tutorial on CircaBred.com is recommended for detailed mathematical explanations.
• 🔌 The setup includes a simple circuit connected to a waveform generator and an oscilloscope.
• 📈 The oscilloscope displays the output of the generator and the effect across the load with different circuits.
• ⚡ A negative series clipper is shown first, which clips the positive part of the input signal, similar to a half-wave rectifier.
• 🔄 Flipping the diode demonstrates a positive series clipper, which clips the negative part of the input signal.
• 🔌 Biased series clippers are shown with a DC offset, affecting the clipping level of the input signal.
• 🔗 Parallel clippers are introduced, where the diode is in parallel with the load, affecting the voltage across the load based on diode bias.
• 🔋 A clamper circuit is demonstrated, which uses a capacitor and a diode to shift the entire waveform up or down in voltage.
• 🎥 The video emphasizes the importance of hands-on experience and practical demonstration for better understanding of these concepts.

Q & A

What is the main topic of the tutorial video?

The main topic of the tutorial video is about clippers and clampers in electronic circuits.

Who created the written tutorial mentioned in the video?

Harold created the written tutorial on clippers and clampers.

What is the purpose of using a waveform generator and an oscilloscope in the demonstration?

The purpose of using a waveform generator and an oscilloscope is to show the output of the generator and what happens across the load with different circuits.

What is a negative series clipper and how is it demonstrated in the video?

A negative series clipper is a circuit that clips the positive part of an input signal, leaving only the negative part. It is demonstrated by showing the output on an oscilloscope after the signal passes through a diode.

How does a positive series clipper differ from a negative series clipper?

A positive series clipper is set up by reversing the diode in the circuit, which results in clipping the negative part of the input signal, leaving only the positive part.

What is the effect of bias on a series clipper circuit?

Biasing a series clipper circuit shifts the entire waveform up or down. A positive bias shifts the waveform up, clipping less of the negative part, while a negative bias shifts it down, clipping less of the positive part.

What is the role of the diode in a parallel clipper circuit?

In a parallel clipper circuit, the diode allows current to flow through the load only when it is reverse-biased, effectively clipping the signal when the diode is forward-biased.

How does the bias affect the output of a parallel clipper?

Biasing a parallel clipper affects the output by shifting the point at which the diode starts to conduct. A positive bias reduces the voltage across the load during forward bias, while a negative bias increases it.

What is a clamper circuit and how does it differ from a clipper?

A clamper circuit is designed to shift the entire waveform up or down without clipping it. It differs from a clipper in that it does not remove parts of the waveform but rather shifts the entire waveform to a new voltage level.

What components are typically used in a clamper circuit?

A clamper circuit typically uses a diode, a capacitor, and a resistor. The capacitor is in series with the diode, and the resistor is in parallel with them.

Why does the clamper circuit not provide a free increase in voltage?

The clamper circuit does not provide a free increase in voltage because it shifts the entire waveform up or down without adding or removing energy from the circuit; it merely redistributes the existing voltage levels.

Outlines

00:00

🔬 Introduction to Clippers and Clampers

This paragraph introduces the topic of clippers and clampers in electronics, with a focus on a tutorial created by Harold. The tutorial is available on Circa Bred Calm and is highly recommended for its detailed explanations involving math. The video aims to demonstrate the practical application of the clippers described in the written tutorial. The setup includes a simple circuit connected to a waveform generator and an oscilloscope, which is used to display the output of the generator and the effect across the load with different circuits. The oscilloscope shows two channels, one for the generator's output and another for the load's output. The video begins with a negative series clipper, which clips the incoming signal, demonstrated with a 60 Hertz input at 10 volts. The oscilloscope displays a flatline when the input is turned off, and the clipper is compared to a half-wave rectifier. The video then transitions to a positive series clipper by simply reversing the diode's orientation, resulting in the negative cycle being clipped. The concept of bias is introduced, explaining how an average offset can affect the clipping behavior. The video concludes with a demonstration of a biased negative series clipper, where an offset is applied to the waveform generator, and the resulting shift in the output is observed.

05:01

🔌 Exploring Parallel Clippers and Clampers

The second paragraph delves into parallel clippers, starting with a setup where the diode is in parallel with the load. The behavior of the circuit is explained in terms of the diode's forward and reverse biasing, affecting the voltage across the load. When the diode is forward biased, there is no voltage across the load, but when reverse biased, the negative dip is observed. The video then demonstrates the effect of biasing the circuit, showing how the clipping behavior changes with a DC offset. The discussion moves on to clampers, where a setup with a capacitor in series with a diode and a resistor in parallel is presented. The oscilloscope is used to observe the waveform's shift due to the capacitor's discharge and the effect of the clamper circuit. The video explains that a clamper shifts the entire waveform up or down without adding or losing voltage, as it's merely a redistribution of the existing voltage. The demonstration concludes with a comparison of the series and parallel configurations of clippers and the clamper, emphasizing the importance of hands-on experience and referring viewers to Harold's more advanced tutorial for further understanding.

Keywords

💡Clippers

Clippers are circuits that limit the amplitude of a waveform to a certain level. In the video, the presenter demonstrates how clippers work by using a simple circuit connected to a waveform generator and an oscilloscope. The script mentions 'negative series clipper' and 'positive series clipper,' which refer to the polarity of the clipped portion of the waveform. Clipping is a form of signal processing used in various electronic applications, such as audio and telecommunications.

💡Clampers

Clampers are circuits that shift the voltage level of a waveform up or down to a specific reference level. The video script describes a clamper circuit that uses a capacitor, a diode, and a resistor to achieve this. Clampers are used to protect sensitive electronic components from voltage spikes or to ensure that signals stay within a certain voltage range, as illustrated in the script by the demonstration of a clamper shifting the waveform down by a fixed voltage.

💡Waveform Generator

A waveform generator is a device that produces specific waveforms, such as sine, square, or triangle waves. In the video, the waveform generator is used to provide a controlled input signal to the circuits being demonstrated. The script mentions setting the generator to produce a 60 Hertz sine wave at 10 volts peak-to-peak, which simulates the typical mains frequency and voltage for testing the clippers and clampers.

💡Oscilloscope

An oscilloscope is an electronic test instrument that allows the visualization of waveforms. In the video, the oscilloscope is used to display the output of the waveform generator and the effects of the clippers and clampers on the waveform. The script describes using both channels of the oscilloscope to show the input signal and the modified signal across the load.

💡Diode

A diode is a two-terminal electronic component that allows current to flow in one direction and blocks it in the other. In the video, diodes are used in the clipper and clamper circuits to control the flow of current and to clip or clamp the waveform. The script explains how changing the orientation of the diode can switch between a negative and positive series clipper.

💡Bias

Bias in electronics refers to a DC offset that is added to a signal. In the video, the presenter demonstrates how biasing affects the operation of clippers by using the waveform generator to apply a DC offset to the input signal. The script describes how this bias shifts the waveform up or down, affecting the clipping point of the clipper circuit.

💡Series and Parallel Configuration

These terms refer to the way components are connected in a circuit. In the video, the script explains the difference between series and parallel clippers. In a series clipper, the diode is in series with the load, affecting the voltage across the load directly. In a parallel clipper, the diode is in parallel with the load, and the voltage across the load depends on whether the diode is forward or reverse biased. The video demonstrates both configurations.

💡Resistor

A resistor is a passive electronic component that opposes the flow of electric current. In the video, resistors are used in the clipper and clamper circuits to control the current flow and to set the level of clipping or clamping. The script mentions a 100k resistor used in the clamper circuit to measure the voltage across the load.

💡Capacitor

A capacitor is a passive electronic component that stores electrical energy in an electric field. In the video, a capacitor is used in the clamper circuit to store charge and to shift the voltage level of the waveform. The script describes how the capacitor, in conjunction with a diode and resistor, creates a voltage shift that clamps the waveform to a specific level.

💡RC Discharge

RC discharge refers to the time it takes for a capacitor to discharge through a resistor. In the video, the script mentions the RC discharge in the context of the capacitor in the clamper circuit. As the capacitor discharges, it affects the waveform's shape, creating a curve as the capacitor starts to discharge before the next voltage peak arrives.

Highlights

Introduction to clippers and clampers in electronic circuits

Recommendation of a written tutorial on CircaBred.com for detailed explanations

Demonstration of a simple circuit setup with a waveform generator and oscilloscope

Explanation of negative series clipper and its function in a circuit

Visual representation of a 60 Hertz input signal on an oscilloscope

Comparison of a negative series clipper to a half-wave rectifier

Setup for a positive series clipper by reversing the diode orientation

Observation of the positive series clipper's output on the oscilloscope

Discussion on biased series clippers and the role of DC offset in circuit behavior

Demonstration of how bias affects the clipping level in a circuit

Introduction to parallel clippers and their configuration in a circuit

Comparison between series and parallel clippers in terms of voltage across the load

Setup and explanation of a biased parallel clipper circuit

Transition to clamper circuits and their function in voltage shifting

Demonstration of a clamper circuit with a capacitor, diode, and resistor

Explanation of how a clamper shifts the entire waveform up or down without adding voltage

Practical advice on hands-on experience with electronic circuits

Conclusion and call to action for viewers to engage with the tutorial and experiment

Transcripts

[Music]

so today we're going to learn about

clippers and clampers now Harold put

this tutorial together and he did a

great job it's a written tutorial on

circa bred calm and I highly recommend

you go check it out he goes into the

details with the math and all that sort

of jazz but today on this video I want

to show some of those Clippers that he

describes in action so here I have a set

up with my very very simple circuit and

it is hooked up to a waveform generator

and an oscilloscope and I'm using both

channels of the oscilloscope to show the

output of the generator and then also

show what happens across the load with

these different circuits so there's a

whole lot of connections here you've got

three grounds here for the two channels

on the oscilloscope and one for the

waveform generator and then I'm

measuring across the load and then I'm

measuring across the entire thing and

then of course the waveform generator

itself is going in so it's kind of funny

to me that I only have two components on

here and six things hook to them but

that's that's how it is so this first

thing that we have is what we call a

negative series clipper and so this

clips the signal that's coming in and so

what I have here is a 60 Hertz because

that's generally we're dealing with wall

frequency if so 50 60 Hertz so I have a

60 Hertz input and I can't do 128 volts

output on this so I'm just doing 10

volts and then I'm showing what it looks

like on this so on the oscilloscope

you'll see the yellow is what is being

measured across the load in the blue is

the output from the waveform generator

so you can see we have five volts per

veted per division so we've got 10 volts

up and down there so if I turn off

channel 2 or the input you can see very

clearly that we just have flatline OOP

flatline and if you've looked at any of

our other tutorials particularly on the

half wave rectifier you'll be like hey

that's just a half wave rectifier and

you would be right and that is what the

first negative series clipper looks like

so now to do a positive series clipper

all we have to do is switch this diode

around and put it in the other direction

so let me do that really quick okay so

it just set it up all I did was flip the

diode around and I hooked everything

back up and you can see that my

oscilloscopes going crazy and that is

because my trigger

at the wrong spot now so I need to

trigger it down there and so it looks

exactly like the positive series clipper

but now it's upside down and all we're

getting is the negative cycle on the

bottom so let's turn that back on so

again this is what the input is and

that's the output is and you can see

there's not going to be an exact overlap

one just because I don't have this set

up super fantastic but also because

there is gonna be the slightest voltage

drop across the diode so you can see the

input is all the way giving me a nice

beautiful sine wave but then my output

it's clipping the top off instead of the

bottom and so that's what you get with a

positive series clipper so now let's go

to the next thing which is the biased

series clipper so we'll up until this

point we've been assuming that the

average is zero and so if we were to

have an op-amp or something some sort of

adder or some sort of DC offset in our

circuit we would see a shift so I'm

gonna flip this diode back around and

I'm going to fake that DC offset with my

waveform generator so let's do that

really quick okay so now I've flipped

the diode back and we are back in a

negative series clipper circuit and you

can see I haven't done the offset yet so

we have our typical output but let me go

over here and change the offset and I

really hope that you have access to

these tools either at school or at work

or something like that so you can go

over and you can do this exact same

thing in your own space and also again

Harold has even more advanced Dennis

demonstrations of how to do this of more

advanced clippers and clampers so if you

have access to this I highly recommend

hands-on and seeing it for yourself

because videos are great but there's

nothing like hands-on experience so

hopefully you can do that but coming

back to this we have our 60 Hertz 10

volts peak-to-peak in zero offset right

now but now let's start to give myself

an offset so I have a two bowl offset

three volt and as you see everything is

getting shifted up and so is this so

you're still getting that beautiful sine

wave and it's just clipping it lower and

lower at that zero point so let me go up

a little bit more if you bias it enough

which that's the max for my arbitrary

waveform generator you can see it's

almost a perfect sine wave but

completely above the zero point and then

if we bias it in the

direction and get a negative voltage

then even less comes up and now we're

getting below the trigger points so it's

not even detecting it but it's just

getting smaller and smaller until

there's nothing left because at negative

five volt DC with a 10 volt peak-to-peak

the very peak of this sine wave is at

zero so of course you're not going to

see it so those are our positive and our

negative

series Clippers with and without bias

now let's move to parallel Clippers okay

so our first parallel clipper is set up

now and really the biggest thing you can

notice here is that the diode is in

parallel with the load so if there's a

voltage across the diode there's gonna

be a voltage across the load if there's

not a voltage across the diode there's

not going to be a voltage across the

load so in this one I have the cathode

hooked up to ground and so when it is

being forward biased there is basically

no there there's a point seven volt drop

in and if we assume diode is ideal there

is no voltage across that so if there's

no voltage across the diode then there's

gonna be no voltage across the load so

we come over here and I need to set my

trigger down here again but we can see

that this is when it is forward bias

because there there's no voltage across

this diode but when it's being reverse

biased that is when you get that

negative dip so let's switch this around

and you can take a brief second wand

switching this to think of what exactly

you think this is going to look like

when it's in the parallel configuration

when the cathode is on the positive side

okay now as I'm sure you figure it out

we're basically seeing the other side we

just inverted it and this is one of

those things if you're doing it in

series or in parallel the way you have

the diode it kind of flips your

understanding because now instead of

measuring the voltage on the other side

of the diode you're measuring the

voltage across the diode and so

depending on what you need to do

depending on what you want to do you can

either do the series or parallel

configuration for a clipper circuit now

let's just bias this really quick there

shouldn't be any surprises here either

and then we'll go on to our clamper

example so make sure I'm on my offset

yep

so acts just like you would expect with

the other one with the series

so as you bias it up you're gonna see

more it's gonna still retain that shape

of the sine wave is just gonna clip off

certain sections clipper clip it off

yeah that's where we're going with that

and then if I reverse bias it it's just

going to go away and the interesting

thing is if you notice earlier with the

series we weren't able to get the very

bottom tip of this whereas we were able

to completely hide it whereas you can

still see little divots here so that is

because we are putting that seven point

seven volt drop somewhere else in the

circuit and so you see a little bit of a

shift there okay so let's put together

the climber alright so I just finally

set it up as they clamp er and as you

can see you have a capacitor that is in

series with a diode and a resistor that

are in parallel and that's something you

can see on the schematic and I again I'm

measuring over the resistor and as the

load and also the over the entire thing

so let's look at the oscilloscope here I

have it 10 volts peak to peak at about a

thousand Hertz I had to change out the

value of my resistor is a 100k resistor

and a now I have a point 1 there at

micro farad capacitor in here and so as

we look at the original what's coming in

let me get that you can see that being a

10 volt peak-to-peak peak to peak you

get a 5 volt jump and then the negative

5 volts +5 volts negative 5 volts now as

we turn the output back on basically

what we're getting is we're getting 0

volts negative 10 volts 0 volts negative

10 volts so we're shifting that peak

basically just taking our entire

waveform and shifting it down 5 volts

and so it's an interesting thing because

we're not in gaining anything here it's

not like we're getting an extra 5 volts

because we're stealing it off the top

here we're stealing it up here and we're

just putting it down there and so you're

seeing a little bit of a curve there

that's because of the time constant of

the capacitor starting to discharge

before it jumps again so that's again

where we're getting those RC discharges

there but a clamper that's what a

clamper does is it'll take your entire

circuit and shift the voltage one

direction or another and again you don't

get anything free it's not like you're

good a bigger

voltage you just shifting it down in

this case but if you switch it also you

can go up and that's it okay so we've

gone over clippers that we've gone over

one variety of clampers again Harold has

a fantastic written tutorial on this

sort of stuff with a couple of more

demonstrations and a lot more math and a

lot more in depth I just wanted to show

you what happens practically wouldn't

you have these things and what it looks

like on an oscilloscope so that

hopefully you can sit in your brain a

little bit more intuitively before you

jump into Harold's tutorial I hope you

enjoyed this video if you did give it a

like subscribe to our Channel and we

will catch you in the next one

you