Components on AddOhms by Bald Engineer

DIY versus Turnkey PCB Assembly with Bald SENSE and MacroFab

Tue, 27 Aug 2024 13:26:00 +0000

My recent experience with the Bald SENSE sensor feather wing project reminded me that time is often our most valuable resource. This video documents the journey that has taught me crucial lessons about design, assembly, and the value of turnkey PCB assembly services. See what went right and what went wrong, and how I ultimately brought this project back to life with the help of MacroFab.

Picking Pull-Up Resistor Values | #25

Thu, 03 May 2018 08:51:00 +0000

A common question that comes up about pull-up resistors: what value do you pick and why not just use a piece of wire? In this follow-up electronics tutorial, the bald engineer looks at how to pick pull-up resistor values.

Show Notes

Pull-Up Resistor Tutorial (Episode 15)
AddOhms Discord Server
Arduino Internal Pull-Up Resistor Tutorial (baldengineer.com)
Chuck Norris On Pull-Up Resistors (baldengineer.com)

Voltage Divider As a Regulator? | #22

Sat, 14 Oct 2017 08:51:00 +0000

Previously, we looked at resistor voltage dividers. Sometimes I get questions about using these instead of regulators. In this video, I show why that doesn’t work. In fact, I go one step further and show that Zener regulators do not work either.

Voltage Divider as a Regulator Show Notes

Links

Zener Diode makes for a lousy regulator 3 (baldengineer.com)

In the episode, I am featuring the Adafruit Huzzah ESP8266 breakout 4. I highly recommend this board if you are interested in the ESP8266. It doesn’t have a serial to USB interface. However, it is far more reliable (and usable) than those worthless $5 8266 boards on eBay. (By Far.)

Brushless DC Motors (BLDC) | #21

Sun, 23 Jul 2017 08:51:00 +0000

Another kind of motor is the BLDC. Otherwise known as the Brushless DC Motor. Unlike the motors we talked about in #20, a BLDC has no commutation ring or brushes. This means no sparks, longer life, and very fast RPMs. Commutation is done electrically. In this video, we show the inside of a BLDC and show two ways to control one.

Brushed DC Motors and how to use them | #20

Thu, 15 Sep 2016 08:51:00 +0000

This Addohms Brushed DC Motor Tutorial goes into the third dimension! Using a variety of 3D models, we show you what makes a brushed DC motor, a brushed DC motor. Then, like usual, we break two simple ways to control them with a microcontroller like the Arduino. You can use a single BJT Transistor (remember those from #10?), build your own H-Bridge, or use a popular H-Bridge chip.

Linear Regulator Tutorial | #17

Sun, 28 Feb 2016 03:09:01 +0000

The LM7805 is a very popular voltage regulator. Curious about how it works? In this AddOhms Tutorial, we look at what is a Linear Voltage Regulator and how to use them in your circuits.

Linear Voltage Regulators Show Notes

LM7805 [Fairchild]
NCP1117 [On Semiconductor]
PIR Sensor [Adafruit]

Interesting Links

Written Tutorial on Regulators [ Baldengineer.com]
TO-220 Information [Wikipedia]
TO-220 Heatsink [Adafruit]
Choosing the right LDO [All About Circuits]

Pull-Up Resistors and Pushbuttons | #15

Mon, 07 Sep 2015 14:13:29 +0000

There is nothing more frustrating than a push button that seems to work at random. The good news is the fix is pretty simple: a resistor.

It may not seem obvious when you first start working with electronics but a “floating pin” doesn’t have a defined “high” or “low” level. Remember from the Analog and Digital video, that Digital Electronics has defined voltage levels. Well, when you don’t connect anything to the I/O pin of your microcontroller, the voltage level is undefined!

How Voltage Dividers Work | #13

Fri, 16 Jan 2015 21:04:12 +0000

https://youtu.be/EQtwsWJuUPs

Understanding voltage dividers means understanding Ohm’s Law. A common use for a voltage divider in most projects is to monitor a battery. Say you are powering your circuit with a 9V or 12V battery. Microcontroller boards don’t do well with those voltages.

In a future video, we’ll come back and look at more circuits that can use voltage dividers.

Episode Notes

Correction: There is a mistake around 3:00. I say “91 millivolts” and I should have said “910 millivolts!”

MOSFETs! (Part 2 of 2 on Transistors) | #11

Fri, 18 Jul 2014 17:02:44 +0000

https://youtu.be/GrvvkYTW_0k

Following up from Episode #10 on BJTs, this episode is focused on introducing MOSFETs. It is the longest video we’ve done yet, coming in just over 7 and a half minutes.

There is a basic overview of how MOSFETs work, compared to a BJT. And something that is really important to consider: how hot is it going to get? So we go through how to calculate power dissipation and if you need a heat sink.

BJTs (Transistors Part 1 of 2) | #10

Fri, 09 May 2014 14:00:00 +0000

https://youtu.be/sRVvUkK0U80

The two most popular kinds of transistors you might use for a project are either BJTs or MOSFETs. With so many options, it was tough to pick just a few.

We covered the 2n3904 in this video. What BJTs are your favorites and why? Leave a comment below.

Transistors are electronic switches that are used to control things that would kill an Arduino, Raspberry Pi, or Beaglebone. There are two major types known as a BJT and MOSFET. This is part 1 of a two part series, which looks at BJTs first.

Episode 8: LEDs and Current Limiting Resistor

Mon, 10 Feb 2014 21:00:00 +0000

https://youtu.be/81zNcctopBI

What was the first electronic component you played with? It was probably a LED. They’re fun to blink in patterns or learn to fade. Most projects (and products) use them for useful indicators.

LEDs add magic to every electronics project. Often not understand is what else you need to make that LED work correctly. Learn what current limiting resistors do for LEDs and watch what happens when you don’t use one.