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Dave takes you through designing a signal overload detector circuit from scratch and then builds it up on the breadboard.
- Window comparators
- Schmitt inverters,
- Capacitor charging,
- Pulse stretching,
- Common mode input range,
- Tongue angle tweaking,
- .. it’s all here.
EEVblog #471 – Overload Detector Circuit Design - [Link]
This is a great video of Alan Wolke talking about op-amp power supply options. He explains the differences when using op-amps on a single supply, a split (or bipolar) supply and virtual ground.
This video discusses the power supply considerations for op amps. It talks about split or dual power supply and single supply operation, and why the op amp often doesn’t care which you use! It shows how traditional op amps designed for split supply operation can be used in single supply applications. The most important consideration generally is taking care of where the input and output voltages are with respect to the supply rails. The input voltage and output voltage range specifications are examined in a datasheet. The operation of a op amp in a single supply application is examined on an oscilloscope. This operation is compared to a modern rail-to-rail op amp in the same circuit.
Op Amp Power Supplies: Split, Single, and Virtual Ground Designs - [Link]
Gil Junqueira write:
It has been 6 weeks since I last reviewed this course. At that time, I was just about to take the mid-term exam. Now it is 6 weeks later — and 14 weeks since the beginning of the class. I finally received my certificate of completion.…
I have to say that these 14 weeks were somewhat painful, as the necessary study required to complete homework in time and keep up with class materials were in direct conflict with my work schedule and ability to spend time with family. This wasn’t without warning, as MIT personnel did indicate that 8 to 10 hours of study time per week would be required in order to keep up with the course.
But at the end, despite all the hours spent on the computer cranking out code to solve problems late at night, (I gave up on doing the math by hand after week and so should you if you take this course in the future) I would do it all over again. This was by far one of the best electronics courses I have taken anywhere. While the material was not completely new to me (I took electronics courses before), the way it was presented was…
MITx / edX 6.002x Circuits and Electronics Course Review - [Link]
Any electronic system generates waste heat during normal operation. This heat must be removed – otherwise, it might damage the system components and cause malfunctions. Whether you are designing a system or diagnosing a system’s cooling requirements, you need to know which parameters to look at and how to estimate the airflow that will maintain a safe temperature within the system.
In a typical cabinet-mounted system, there are usually one or two power supplies, electronic circuits and displays, all of which can be assumed to generate heat within the cabinet. From the system’s power requirements, a fair idea of the power input may be estimated. If the system is cooled by simple convection, the thermal capacity of air can be taken to be 0.569W-minute/°C/ft³.
That means, every cubic foot of moving air can remove 0.569 W of dissipated heat every minute when its temperature changes by 1°C. To express it reciprocally, to dissipate 1W of heat, and maintain a 1°C change in temperature, an air stream of 1.757cfm (1.757 cubic feet per minute) will be required. Therefore, once you have estimated the heat dissipation within the system, estimating a cooling fan’s rating in cfm will depend on the internal temperature rise you allow. However, until you have completed your measurements and fitted the right size of fan, there will always be the risk of failure of system components. Therefore, for experimentation, what you need is a representative model.
Book #1 : Starting with the electronics hobby – Free to download
Other 4 ebooks are available to purchase. John @ www.theelectronicsbook.com writes:
This book will teach you all the basic rules of the electric circuits world. It will guide you step by step with pictures and examples. More than 80 pages of theoretical and practical information.
This book includes the following subjects: Electric current, voltage, Resistance, Water-electronics analogy, Ohm’s law, Waveforms, What is a multi-meter?, Using multi-meter, Component’s part number, Symbols of components , Searching methods for components, datasheets, Resistance color code, Circuits with resistors , Experiment: Resistance measurement and many more basic rules of the electronic circuit.
No previous knowledge is required. Starting from the basics and moving on to practical electronics. Many examples and experiments on every electronic component. Full of pictures for better understanding.
Free ebook – Starting with the electronics hobby - [Link]
If you are someone who enjoys doing your own home improvement and you are working with electronics during the process, having access to a multimeter is an absolute must. There are going to be instances where you will need to be able to measure voltage, ohms and continuity and without an electronic multimeter, it will be difficult to determine just what you need to do. Here are a few tips for using your multimeter to perform home improvement projects.
- Understand your options – Multimeters are available in different types. These can run from the most basic to the most luxuries, which is also the most expensive. Unless you have highly advanced electronic skills and knowledge, a basic multimeter is going to be just fine and will have fewer features that you need to figure out.
- Familiarize yourself with your multimeter – Take some time to examine the multimeter before you use it. When looking at the face of the design you should see three different things – dial, settings and lead ports. These should be color coded which makes it much easier to avoid mistakes when plugging in leads.
- Learn the dial settings – As you look at the dial, take notice of the symbols and numbers that surround it. You should see an arrow that points to the right with a plus sign beside it. This is the setting that is used for continuity. The “V” setting is used for voltage and the setting for ohms or resistance will look like a “0” with feet.
- Learn the uses of your multimeter – You can test a random electrical outlet to make sure that the multimeter is working properly. Use the “V” setting for this. Check to ensure that power is not flowing through any electronic circuits that you are testing. If you would like to test for a blown fuse, remove the fuse from the clamps and set the meter for continuity testing. Simply touch each end of the fuse with the meter’s probe and if the fuse is operating properly you should hear a beep.
- Test for amperage – When testing for amperage you have to be a bit more careful. This is a more complicated process and requires that you use more than just two probes. You can use a clamp add-on for amperage testing by plugging it into two ports that read “A” and “Com.” Clamp the tester onto the hot wire that you want to test or you can simply purchase a plug that includes a wire loop specifically designed to test amperage.
This article was written by Electric Point, one of the largest independent wholesale groups in the UK and Ireland. Visit us today at electricpoint.com
Rectifier circuit with very low voltage drop featuring a P-channel MOSFET - [via]
Different ways you can protect your circuit from backwards power connections. Diodes, schottky diodes and P channel MOSFETs.
P-FET Reverse voltage polarity protection tutorial - [Link]
This video covers the basics of diodes, bridge rectifiers, and how to build simple unregulated AC to DC power supplies than can handle a few mA up to several Amps. Diode Tutorial & How to build an AC to DC power supply - [Link]
www.adafruit.com writes:
Having a hard time trying to figure out whether that FET can handle enough current for your project? AN11158 from NXP might help clarify some of the many parameters that you need to take into account that are often overlooked. The Safe operating area, for example, is an important one that often gets skipped and people just look at the best-case scenario marketing numbers on the front page of the datasheet: “The Safe Operating Area (SOA) curves are some of the most important on the data sheet. The SOA curves show the voltage allowed, the current and time envelope of operation for the MOSFET. These values are for an initial Tmb of 25°C and a single current pulse. This is a complex subject which is further discussed in the appendix (Section 3.1).”
Understanding power MOSFET data sheet parameters - [Link]
