Видео 32
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They Do It with Mirrors: Transistors 101, episode 12

13:19

The Ebers-Moll Transistor Model - Transistors 101, episode 11

12:42

The Shockley Diode Model - Transistors 101 episode 10

10:05

Transistor 101 Side Project: Current-Voltage Curve Tracer: part 3: Software (RE-UPLOADED)

11:00

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 2: Build

12:08

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 1: Design

12:43

Improved Current Mirrors - Transistors 101, episode 13

Improving on the current mirror
The simple two-transistor current mirror that we saw last time
has problems with its output impedance/voltage compliance and
its accuracy.
This video presents a collection of designs that improve
on its limitations with a few extra components.
Schematics are on the project GitHub:
github.com/kennykb/kevins-cave-kludges/tree/main/Transistor101/Ep012-Mirrors
(Yes, I know it says episode 12. I use the same test circuit to evaluate these mirrors.
TIMELINE
00:00 Intro
01:24 Emitter resistors
06:11 Widlar asymmetric mirror
07:35 Wilson mirror
11:32 Symmetric Wilson mirror
14:25 Matched transistor pairs
16:12 Outro
CREDITS
Music:
“Light Sting” Kevin MacLeod (incompetech.com)
Licensed...

Видео

They Do It with Mirrors: Transistors 101, episode 12

13:19

They Do It with Mirrors: Transistors 101, episode 12

Просмотров 7 тыс.День назад

Transistors 101, episode 12 They Do It with Mirrors We examine a simple two transistor current mirror, a circuit that regulates its output to have an equal current to its input. The circuit can be used to balance the currents in two parts of a larger design, or to reverse the direction of current flow (turn a current source into a current sink, or vice versa). Schematics are on the project GitH...

The Ebers-Moll Transistor Model - Transistors 101, episode 11

12:42

The Ebers-Moll Transistor Model - Transistors 101, episode 11

Просмотров 87814 дней назад

We use our simple test rig to measure how a transistor's collector current varies with the voltage between base and emitter. With the data from this test, we present the Ebers-Moll model, where the collector current is an exponential function of the base voltage. We learn why transistor beta is still a useful model, although it's incomplete. We learn to do small-signal analysis using Ebers-Moll...

The Shockley Diode Model - Transistors 101 episode 10

10:05

The Shockley Diode Model - Transistors 101 episode 10

Просмотров 1 тыс.21 день назад

Using the test rig that we recently built in the 'side project' to characterize diodes and demonstrate the Shockley diode equation that relates forward current to forward voltage. This is the first step to characterizing transistors. Next episode will use the same test setup to measure a transistor and demonstrate how it's a voltage-controlled current source. Files documenting the test rig can ...

Transistor 101 Side Project: Current-Voltage Curve Tracer: part 3: Software (RE-UPLOADED)

11:00

Transistor 101 Side Project: Current-Voltage Curve Tracer: part 3: Software (RE-UPLOADED)

Просмотров 750Месяц назад

THIS IS A RE-UPLOAD. The first copy somehow linked to the wrong video! Sorry! Third episode in a series presenting a side project: building a fairly simple tester to plot the current-versus-voltage curve for a device (with a current range of six orders of magnitude). The first episode covered designing the circuit¸ and the second built and debugged it on a breadboard. In this episode, we build ...

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 2: Build

12:08

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 2: Build

Просмотров 1,8 тыс.Месяц назад

Second episode in a series presenting a side project: building a fairly simple tester to plot the current-versus-voltage curve for a device (with a current range of six orders of magnitude). The first episode covered designing the circuit. In this one, we build and debug it on the breadboard. 00:16 Review the design 01:00 Building and adjusting 03:55 Testing an actual device 05:10 Trouble at na...

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 1: Design

12:43

Transistor 101 Side Project: Current-Voltage Curve Tracer, part 1: Design

Просмотров 2,6 тыс.Месяц назад

First episode in a series presenting a side project: building a fairly simple tester to plot the current-versus-voltage curve for a device (with a current range of six orders of magnitude). 00:15 Why this project? 02:32 Wnat will it do? 03:45 Block diagram 05:07 Current sensing 07:14 Voltage ramp generator 09:07 Reset signal 11:46 Onward to the build! Be sure to catch the next episode, where we...

Bandgap Voltage Reference - a Better Zener Diode

20:15

Bandgap Voltage Reference - a Better Zener Diode

Просмотров 7 тыс.Месяц назад

A viewer asked why I don't stock Zener diodes routinely. I was going to do a quick five-minute reply, but it turned into a deep dive into the workings of IC bandgap voltage references, leading up to building a 7.5 volt low-current supply that achieves 0.1% accuracy over 0-20 mA loads. I decided to make this episode a fairly complete log of designing, breadboarding and testing the circuit, inclu...

Transistors 101 episode 9: The Quest for More Voltage Gain

13:13

Transistors 101 episode 9: The Quest for More Voltage Gain

Просмотров 2,5 тыс.2 месяца назад

Last time, we chased after current gain in our transistor circuits. This time, we go after voltage gain. What are the limits for voltage gain in a single stage? Schematics of what we built and tested are on the project GitHub: github.com/kennykb/kevins-cave-kludges/tree/main/Transistor101/Ep009_MoreGain 00:33 A tiny emitter resistor? 02:47 Building circuit with a tiny resistor 03:25 Missed the ...

Is an integrator the same as a low-pass filter? Exploring Analog Synthesis, ep. 7a

6:28

Is an integrator the same as a low-pass filter? Exploring Analog Synthesis, ep. 7a

Просмотров 2,2 тыс.2 месяца назад

In my recent video about op-amp integrators, a viewer asked, 'isn't an integrator just a low-pass filter?' In this video, I try to answer that question. I compare schematics of an integrator and a low-pass filter, build them both on the breadboard, test them over the audio frequency range, and compare their frequency response in both amplitude and phase. Conclusion: No, they're not the same. As...

Transistors 101 ep8: The Quest for Current Gain

12:30

Transistors 101 ep8: The Quest for Current Gain

Просмотров 1,1 тыс.2 месяца назад

A few ideas for what to do when your transistor's beta (current gain) just isn't big enough. Schematics are on the project GitHub: github.com/kennykb/kevins-cave-kludges/tree/main/Transistor101/Ep008_MoreGain CircuitJS model of the saturated Darlington: tinyurl.com/25zoqoap TIMELINE 00:10 Intro 01:50 Superbeta transistors 03:30 The Darlington pair 04:45 Demo of the Darlington pair 05:56 Darling...

What's in my parts box? Discrete semiconductors!

13:36

What's in my parts box? Discrete semiconductors!

Просмотров 1,2 тыс.2 месяца назад

What's in my Parts Box? Discrete semiconductors ERRATUM: At about 7:52, I mention in passing BD547/557/847/857 transistors. That was a typo that manged to get into my voiceover as well. The correct part numbers are BC547/557/847/857. In this second video of a short series, I discuss the diodes and transistors that I use in projects, and how to look for substitutes for any part numbers that you ...

11:51

What's in my parts box? 1: Passives

Просмотров 1,1 тыс.2 месяца назад

I've been getting a few questions about why I selected specific parts. This is the start of a short series explaining what parts I keep on hand and reach for when designing, to answer some of the commonest questions. This episode discusses passive components: resistors, capacitors, and inductors. 00:11 Intro 01:11 Resistors 03:57 Potentiometers 05:05 Trim pots 05:55 Capacitors 06:25 - ceramic 0...

Transistors 101 ep7: Biasing the common emitter amplifier

11:46

Transistors 101 ep7: Biasing the common emitter amplifier

Просмотров 1,5 тыс.2 месяца назад

Now that we know about transistor beta, we can work out biasing for the transitor current source and the common emitter amplifier, and know their input and output impedances. Just as with the follower, we can improve the input impedance of the common emitter amplifier by bootstrapping the bias network. The spreadsheet used here and the CircuitJS models are on the project GitHub: github.com/kenn...

Audio Synthesis ep7: The Op-Amp Integrator

14:06

Audio Synthesis ep7: The Op-Amp Integrator

Просмотров 11 тыс.3 месяца назад

An op-amp, a resistor, and a capacitor make a circuit that can do calculus! The op-amp integrator will be a basic building block of oscillators, filters, AGC circuits, and who knows what else? I don't have an immediate audio use yet, but I need one on a side project for this channel, so I'm presenting it now. As always, supplementary material is on the project GitHub: github.com/kennykb/kevins-...