Careers and Hobbies in Electronics Design - Starting With 555 Timer Circuits

Want to learn how to make circuits? As you have probably guessed, there are many tutorials online for getting into circuit analysis and design, but as a novice, you probably have no idea where to start. If you are somewhat up for a challenge, learning how to build 555 timer circuits can be very rewarding and give you a real advantage in your personal projects or in industry. This is because 555 timer circuits are used in a plethora of electronics devices used today (especially digital devices).

The reason you want to start learning 555 timing circuits as soon as possible is because you will learn the majority of the fundamentals of circuit analysis and design all in one circuit, but also because of the incredible utility this specific type of circuit has to offer for many types of implementations. The most famous of the basic 555 timer circuits is the one that allows the blinking of an LED (light emitting diode) at the rate which you specify when you build the circuit. The rate of flashing/blinking is decided by the time constant of your circuit, which is calculated by your resistance times your capacitance.

It may all seem a bit intimidating, but you will have a lot of resources at your disposal revolving around 555 timer circuits, and the internet is a great place to start.

Manufacturers of the IC used in 555 timer circuits, like those of all other electronic elements, provide a datasheet that you can download for free as a published document file. The datasheet offers a tremendous amount of very specific information about the electrical element, but you will need to take a look at good examples of complete 555 timer circuits in order to replicate and understand them fully.

Digital devices incorporate these circuits to provide a serial clock function that times the sequence of bits that comprises the binary code that makes them work the way they were intended. This means that 555 timer circuits are useful for much more than just timing or counting. Hundreds of thousands, or even millions, of electronics used today incorporate these circuits and would not function without them. Now do you see the importance of why you should learn them right away?

You cannot really avoid learning 555 timer circuits if you plan to get into serious electronics design and want to build your own circuits. Their utility is endless, but the amount of electrical engineering experience you get when building them is perhaps more than when building any other type of entry-level circuit. Start by watching a video on YouTube to get an idea of what exactly it is and what it is capable of doing in simple applications.

A Young Teacher's Guide to Writing Assessment Tasks

The process of learning to write and administer assessment tasks will always be a work in progress. There will always be ways to improve your assessment techniques. You can do this first by reviewing each item after you have completed marking your students' efforts. If you don't do the review and use the item/s again, you will perpetuate the mistake of using a poor assessment task.

Unfortunately, some teachers have believed in the past that their assessment task was perfect and that the students had not done the work to succeed. In fact, the opposite was often true. The assessment task had not shown what the students had known but what they did not know. This situation had often created a real fear of traditional examinations in the minds of students. The profession, in some cases, put it down to poor exam technique when the students, in reality, were given a poor assessment task. Therefore, it is imperative that we write assessment tasks that test what we teach and reflect how we teach.

For the young teacher starting out, remember your own experiences of assessment as a student to help guide you along the way.

Don't just use items you have collected along the way or are given to use when you start your career. By all means, use what you are given as a guide. Alter it to fit into your teaching approaches. Have a teacher mentor on your school staff review it with you before you use it.

What follows are suggestions of a general nature which will help you in an organizational sense to get your assessment development underway. There are no suggestions of a subject discipline nature. You will get these during your training, your teaching practice and from senior staff when you are appointed to your school.

When You Are In Training:

    Collect examples of as many different assessment tasks at all year levels you might teach.

    Make sure you have an answer sheet and marking scheme/criteria to go with each item.

    Write your own assessment tasks to test out the success of your practice teaching program.

    Review each assessment task you use and rewrite it as necessary. Make notes on how to administer it as well as how successful it was.

    Organise an assessment folder in year levels and subject disciplines.

When You Begin Teaching:

    Continue to gather assessment tasks as you go for your assessment folder.

    Most schools and/or teachers will have past copies of all their assessment tasks on file. Sometimes, these will be on the staff or subject area school intranet. Consult and use these as initial guides to gain an idea of the standard of questions you might ask.

    Don't just copy items or tasks or exams in full. Do this only if it fits what you want and reflects your teaching approach for that topic.

    You can use old test items as practice tests for your students. These practice tests will provide ideas for your own tests if you mark the practice tests yourself.

    Decide, beforehand, what skills/procedures you want to test. These should be the basic skills/procedures on which the topic is built.

    Initially, write the assessment items to test these skills and procedures.

    Now, write items that bring these skills and procedures together to complete more complex tasks. These could be tasks of a problem solving/critical thinking/higher order thinking nature.

    You must make sure that you have a range of questions from the simple to the difficult/complex. This gives every child the chance to succeed in some way.

    Putting it a different way, your assessment items must test what basic skills and procedures they know and, later, in the assessment items, how they apply these together in more complex situations.

    Do the assessment items yourself from the printed draft to test their validity and your suggested time requirements. Look for printing errors, errors of meaning and so on.

    Amend the assessment items yourself. Then have another teacher proof read it and comment on it.

    Do an answer sheet/model answer and determine the marking scheme or criteria. Put the marking scheme/criteria on the assessment tasks.

    Write a clear set of instructions on page one of the printed paper. Include the time limit as well.

    A rule of thumb that was suggested to me, early in my career, was to multiply the time you take to do an assessment task or examination by three to get an idea of the time students would take to complete that assessment task. Use this as the time you would give the students to complete the task.

In conclusion, remember to make your first goal in all your assessment tasks to find out what the students do actually know. This will lead you to know what they need to know and your second goal. This will be to revise that knowledge to give your students what they need to succeed in the next teaching period. Lastly, always review each assessment task with the goal of improving it so you can use it again in the future.