You’ve found a cool 555 timer project online or in my book, procured all of the parts, wired them up on a breadboard, and are now ready to power up your newly made creation. Time for the moment of glory. You slide the power switch on and… nothing, it’s not working how you expected, or worst case scenario – the magic smoke escapes one of your parts.

It’s happened to the best of us and will continue to do so. These have been my four most common 555 timer circuit mistakes, and are common in most other breadboard projects.

Wiring/Placement Mistake

I would say this is the most common cause for error that I have experienced, especially with breadboard circuits. All it takes is for one wire or part to be off by one hole on the breadboard, or you have a particular component flipped around backward, and your circuit will probably be rendered inoperable.

Solution: Double, even triple-check your wiring. Ensure all chips and polarized components are placed in the correct orientation. Methodically follow the current flow of the schematic in comparison to your breadboard circuit.

Wrong Component

Almost a tie for the most common problem I’ve experienced is using the wrong component. An incorrect value of a resistor, capacitor, etc., is easy to do with small, sometimes cryptic labels on parts.

Solution: Similar to the wiring mistakes, carefully check each component label to make sure it’s the correct value.

Low Battery Voltage

Your circuit works perfectly once, but not the second time you test it, even without changing anything. The timing is off, LEDs are barely lighting, what the heck is going on? After checking many iterations of a circuit or leaving it on for a while, that 9-volt battery may only be at 7 volts, and things may start to get a bit wonky. The 555 is fairly immune to supply voltage differences. However, when a battery nears the lower end of its capacity, the increase in internal resistance of the dying battery reduces the available current to the point of rendering your circuit or device useless.

Solution: If you notice any of the issues mentioned above, fire up your trusty multimeter and make sure the battery voltage for your circuit is at an acceptable level.

Capacitor Leakage

After thoroughly troubleshooting every tip mentioned above, the timing cycle of your project “hangs.” An LED should turn on and then off in monostable mode but instead stays on, or your astable mode circuit doesn’t oscillate from one state to the next, etc.

If your circuit uses a large value timing capacitor (usually for longer timing periods), the culprit of the behavior described above could be a leaky capacitor. What is capacitor leakage? When basic electronics are taught using the water (hydraulics) analogy method, a capacitor is usually represented by a pipe with a perfectly sealed flexible rubber diaphragm in the middle that prevents water from passing through.

To use that analogy to describe capacitor leakage, the diaphragm isn’t perfectly sealed, and a small amount of water (current) does leak through. Large electrolytic capacitors are known for having a higher leakage current than most other types. This can cause issues for time-sensitive circuits.

Another way to visualize leakage current is in the diagram to the right. Imagine a resistor in parallel with the capacitor allowing a small amount of current to pass.

I have had a brand new 50-volt, 1 uF electrolytic capacitor by one manufacturer only charge up to 2 volts when 9 volts were applied due to high leakage current. All of my other caps by different manufacturers with the same ratings worked fine. It took me a while to figure out what was going on.

Solution: For more critical timing applications tantalum or Mylar and other film type caps usually work best. If you have to use electrolytic caps, at least use low tolerance, high-quality ones. You can usually find the leakage current specs on the manufacturer’s data sheet.

Wrapping Up

These are the most common errors I’ve run into while working with breadboard circuits. How about you? What have been your biggest 555 timer circuit mistakes? Give everyone a heads up of what to look out for in the comments below!

The post Four Biggest 555 Timer Circuit Mistakes appeared first on Bent-Tronics.

In this video, I show what the completed projects from Chapter 7 should look like.

Errata:
Project 5 parts list – Optional caps C4 and C5 are shown in the schematic and breadboard layouts, but not listed in the parts list. Both should be .01 uF

The post My 555 Book, Chpt. 7 recap: Audible Anarchy with the Atari Punk Console appeared first on Bent-Tronics.

In this video, I show what the completed projects from Chapter 3 should look and sound like.

Buy the book here.
Buy the complete parts kit here.

The post My 555 Book, Chpt. 3 recap: Basic Astable Mode appeared first on Bent-Tronics.

In this video, I explain the basics of breadboards, and how to transfer a simple schematic to a working circuit on a breadboard.

Buy the book here.
Buy the complete parts kit here.

The post My 555 Book, Chpt. 1: How to use a breadboard, transfer schematics to a working circuit appeared first on Bent-Tronics.

Until now there hasn’t been much on the interwebs on how to set up the Dangerous Prototypes Bus Pirate for decoding MIDI data.

Here’s my contribution, which happens to be on International Talk Like a Pirate Day.

Bus Pirate on Amazon: http://amzn.to/2dcZ9uS
Bus Pirate on SparkFun: http://bit.ly/2bKjZfT
TyMkrs MIDI In Me: http://bit.ly/2cihEdA

The post Video: Talk MIDI with the Bus Pirate on Talk Like a Pirate Day appeared first on Bent-Tronics.

I got my first miniAtmegatron (I have two as of now) about a year ago. I have to admit after I put it together and made this video of the assembly and a quick run through of its sounds, I let it sit a while. Part of the reason I let it sit was that it didn’t have any type of “Getting Started” guide, or even a manual (beyond the small 2-page pamphlet that named the Functions).

After making a video about the new case for the miniAtmegatron, I decided to make a video getting into some of its more in-depth features. Coincidentally, when I had a few questions for the synth’s creator Paul Soulsby, he mentioned he was working on a proper manual for the miniAtmegatron and sent me an advanced copy.

So check out my video below, and be sure to keep watch at the Soulsby Synthesizers website for the new manual.

Let me know what you think of the miniAtmegatron’s capabilities and sounds in the comments below.

The post Video: miniAtmegatron Demo & Sneak Peek at the New Improved Manual appeared first on Bent-Tronics.

Here’s a video of me assembling the case for the miniAtmegatron, which can be found here at the Soulsby Synthesizers site for about $20.

Click here to read my blog post and watch a video of the assembly and quick demo of the miniAtmegatron itself.

What do you think of the case? Let me know in the comments below.

The post Video: miniAtmegatron Case: Assembly & Overview appeared first on Bent-Tronics.

Tripods get in the way, boom arms are either unstable or expensive. For many years I struggled with shooting video or pictures from an overhead viewpoint. This week, I finally decided to do something about it.

With just a few pieces of extruded aluminum, some plastic brackets, an aluminum bar, and a commercial camera mount for car windows, I was able to successfully put an end to my struggle. The extruded aluminum and plastic brackets are Opensource Hardware from Openbeam. This means you could easily 3D print or mill accessories to further customize your own rig.

Parts  List

OpenBeam Starter Construction Kit: http://amzn.to/29VfZKc

OpenBeam Kossel Pro, Extrusions: http://amzn.to/29C8PhO

Alpen Car Window Mount: http://amzn.to/29VfOij

3-ft x 2-in 1/8″ Flat Aluminum Bar Stock: http://low.es/29tMP50

The post Video: Make this helpful Overhead Camera Rig using Open Source Hardware appeared first on Bent-Tronics.

Sometimes you just need to know if a MIDI controller is outputting anything. Even many high-end MIDI modules/boxes will have a “MIDI Activity” light, just to let you know something is being transmitted/received. That’s what I have made in this video.

Using a sacrificial MIDI cable, an LED, and a 220 Ohm resistor, you too can make this tester/activity light, probably in less than 10 minutes. Here is a rough wiring diagram.

There really isn’t too much critical about the parts used. MIDI devices use a 5 mA current loop at 31.25 Kbaud as part of their serial communication protocol. Most LEDs and a ~220 Ohm resistor will result very close in the neighborhood of 5 mA when used in this circuit. Devices with a MIDI input have basically this same thing as the LED, except in the form of an optoisolator IC.

If you don’t want to sacrifice a MIDI cable you currently own, cheap ones can be found here on Amazon, and here on eBay.

I’ll be exploring MIDI much more in-depth in future videos. Let me know in the comments below if you have any ideas/questions for future videos about MIDI.

The post Video: Make the World’s cheapest MIDI Tester appeared first on Bent-Tronics.

The power supply in question is an HQ Power (Velleman) PS1503SBU (Amazon; Jameco). I was able to replace the factory single turn pots with these 10-turn pots from Jameco, and now have more precise control of the voltage and current settings.

The formula for adding the 22k pots in parallel to the 10k pots is: R_total = R1×R2/(R1+R2)

The post Video: I add 10-turn pots to my variable power supply for more precision control appeared first on Bent-Tronics.