555

174 Articles

555 Inductance Meter

February 25, 2011 by 7 Comments

[Apexys] is performing some experiments with switched-mode power supplies and needed to compare the inductance of the coils he was using. His multimeter doesn’t have an inductance testing function, but he does have a 555 timer on hand. He put the 555 and some other parts together to create his own L meter. The writeup includes the theory behind this meter, with an incoming AC source converted to a voltage by an RC network.

Once he’d worked out the design it was time to build the circuit. Instead of printing a circuit board he created what he calls a DCB; Drawn Circuit Board. We’ve got to admit that this was way faster than using toner transfer or soldering point-to-point. We also like his use of an Erlenmeyer flask and a torch to heat the etchant. We don’t make PCBs in the winter because our Cupric Chloride is too cold to use outside but that may change now. The final piece in the puzzle is an analog meter which he pulled from an extra microamp meter he had on hand. Check out the demo after the break.

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Building A 555 Timer From Discrete Components

February 25, 2011 by 18 Comments

The 555 Design Contest shook a whole bunch of really creative circuits out of the trees, hence the 555-heavy content lately. While not technically part of the contest, [esalazar] wanted to know what made the 555 tick, literally! He started working on the project in a circuit simulator, then ultimately ended up building the three main logic blocks inside the familiar timer on pieces of copper-clad board. He’d built a 555 using discrete components.

While this isn’t 100% compatible with the classic 555 IC, it covers the basics pretty well, and [esalazar] gets extra-credit points for embracing the hacker spirit of seeing for himself how stuff works while documenting it well and citing his references.

555 Video Game

February 24, 2011 by 20 Comments

[Thrashbarg] is back up to some 555 timer madness again, this time with his sort of dodge ball video game. Featuring twenty three 555 timers, op amps (the LM324) and atari paddles slightly modded so the pots act as voltage dividers.

Output is on a monochrome composite tv signal, and the game plays like a dodge ball game where the object is to avoid the ball and take out the other player. You can also launch your own ball and deflect the oncoming attack. When hit the defeated player disappears from the screen for 3 seconds and then another round starts.

On a personal note this project hits close to home, as the project I had planned was a 555 based pong game, and just days before the deadline all I have is a wobbly sync generator, so seeing something close to what I had imagined, and working, makes me smile and feel a little better about my mental status.

Check out a short video after the break, and [Thrashbarg’s] previous 555 project, The Synthanola.

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555 Timer-based Charge Controller

February 24, 2011 by 13 Comments

555_charging_controller_circuit

Several years ago [Michael Davis] built a charge controller for his wind turbine and published his construction plans online. This build became quite popular, especially among people that live in remote regions. He states that he is flooded with email each day with questions about his charge controller from people trying to troubleshoot its construction or from people who are unable to source the proper parts.

In order to make things easier for people, he decided to revisit his controller design to see what could be improved, and more importantly, what could be removed. The revision was shelved for awhile, but while in the process of working on another project, he realized that most of his original circuit could be easily replaced with a 555 timer. Since the 555 chip is so ubiquitous, he figured it was a fantastic way to simplify his charger, even if he wasn’t using the chip in the manner for which it was originally designed.

He continued revising his charger, sourcing very basic components and simplifying the circuitry enough that even he was able to build it correctly the first time around. Needless to say, this charging circuit will be his entry in the 555 Design Contest.

Be sure to keep reading for a quick video of his charger in action.

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555 Cartoons

February 22, 2011 by 10 Comments

Drehkino is a Turntable Cinema that plays short (50 frames) looping animations from specially printed, disks, and is housed in a wooden frame similar to a record player. The paper disks are the frames of animation and an optical rotary encoder pattern, that pattern is picked up by a infrared pair scavenged from an old mouse. The signal is then passed onto a 555 timer configured as a Schmitt trigger that (indirectly) drives the led strobe light creating animation that is synced to the speed of the turn table.

That sounds all good and well, but it must be a big pain to split up an animation and calculate each frame’s position etc, well that is covered too by a couple scripts. Movie clips are sent though virtualdub to select what 50 frames you want, then are exported to individual images, an sh script then takes over and gawk is used to manipulate the data and create an ImageMagick (“CONVSCRIPT”) file. After you do the script dance you are left with a perfectly spaced wheel with encoder ready to print on standard paper in a PDF format.

Software and schematics included, with future improvements already in the works and its nifty, so its worth a check. This is an interesting take on the old zoetrope design.

Multitool Alarm System

February 9, 2011 by 44 Comments

Here’s a way to make sure you don’t leave your Leatherman multitool somewhere. It’s an alarm system that will start a timer when the tool is removed from the holster. After five minutes the module beeps to remind you to put the tool back where it belongs. Annoying? Possibly, but if you’re not done with your work just press the reed leaf switch on the module to reset the timer. A PIC 12F683 handles the timing and generates the waveform for the piezo buzzer. Perhaps this could have been accomplished with a dual 555 chip like the LM556 (one timer for the countdown and another for the piezo waveform) but the PIC has power-down modes available that should make the button batteries last a long time.

More 555 Projects To Enjoy

February 7, 2011 by 9 Comments

We love all of the projects that are coming out for the 555 design contest, so we thought we would share a couple more that have caught our collective eye.  Have a 555 project of your own? Be sure to share it with us, and keep an eye out for the contest submission dates. Read on for a few of our project picks.

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