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Nixie Clocks – Early Designs

Nixie Clock with Arduino

Nixie Clock with Arduino
I got my first Nixie tubes in early 2016 and started experimenting. I didn’t know anything about then at the time, but quickly realized that they were pretty simple devices to use.

Only part that needed developing was the high voltage power supply. I did not want to use mains AC as the power source, and ideally wanted to use 5V DC so that the clock can be powered from USB.

After a bit of research I found that most of the high voltage power supply designs use boost converter driven by a PWM controller IC. A large MOSFET switching a good size inductor. Those designs looked a bit overkill to me, so I started designing my own from scratch.

Since I’m familiar with transistor based blocking oscillator circuit to boost voltage, I wanted to see if I can use similar circuit. The switching transistor has to withstand the output voltage of 180V so I picked some high voltage transistors and experimented. Turned out that typical high voltage transistors (C-E breakdown of more than 200V) were too wimpy for the purpose, and the simple two transistor circuit that I was using was not capable of very high duty cycle demanded by high input/output voltage ratio (I’d estimate close to 99%).

One way to reduce requirement for the boost converter is to add voltage multiplier at the output. I added a 3 stage Cockcroft–Walton multiplier to a circuit using pretty ordinary (inexpensive) transistors. This circuit was able to provide required voltage and up to around 3 to 4 mA of driving current to medium sized Nixie like IN-12.

While this power supply was not quite powerful enough for larger Nixie tubes, I went ahead and designed a clock circuit to get my feet wet.

Nixieduino-rev1-schematics
First design was a 4 digit clock using ATMEGA328 – I wanted to make the software easy to develop, so I loaded Arduino boot-loader. I also wanted to use the clock as a multipurpose numerical display so I added a V-USB port.

Nixieduino rev.1
This prototype had some stupid bugs, but the basic functions such as multiplexing worked. I made a revision of this prototype right after.
Second Nixie clock prototype
Nixieduino rev2 schematics
Here I experimented with a tapped inductor to effectively double the boost converter output voltage and do away with voltage doubler instead of tripler.


Are Nixie Tubes cool again?

Nixie clock prototypes

Nixie clock prototypes
I’ve been playing/designing with Nixie tubes for some time now. I found Nixies very fascinating as the numbers inside them glow just magically.

There are many Nixie Clock designs available on the net. They are usually two types; AC main powered clock without MCUs, or low voltage DC powered with MCUs. I prefer low voltage variety because of the safety reasons, as I like exposed PCBAs.

All of the low voltage designs have some kind of high voltage (180V typical) generation circuit – and I noticed that all of the designs that I see use a pretty hefty MOSFET driven by a PWM controller IC. Somewhat complex and not so small. I kept thinking – there has to be a simpler solution.

I’m sure many people reading this are familiar with Joule Thief circuit. It’s a simple blocking oscillator based boost converter. I have done some work with two transistor variation of Joule Thief extensively, and thought I should be able to use that circuit for Nixie power supply.

Looking at the basic circuit I realize that the output voltage is limited by the breakdown voltage (Vceo) of the switching transistor. So I tried testing with high voltage capable transistors. The result was not so good – you can get the voltage, but could not deliver the current Nixies needed.

So I decided to add voltage doubler to the circuit, which looked promising. After many tries with different transistors and voltage doubler or tripler combinations I was able to come up with a supply that can deliver about 7mA of driving current into a medium sized Nixie. The circuit only uses two transistors, a not so big inductor and a few diodes and capacitors. It is much simpler and smaller than all of the Nixie power supply I have come across.

It’s not as strong (only 180V and 7mA driving current as opposed to 200+V with 10+mA) and voltage regulation is not so good. However it’s more than good enough for small to medium sized Nixie tubes. It can also work with input voltage as low as 2.4V when you don’t need much output current (i.e. miniature Nixies like IN-17).

I have designed a couple of Nixie clocks using this power supply. I will follow up with some descriptions of each stage of the designs.


Website Renewed

Some of you may have noticed that The LED Artist website has been renewed.

It was long time over due, but finally done. What pushed us to finally change the website was PayPal. They decided that it’s time to put a “hold” on our money and held it for days for no good reason. Looking back I knew that it was a bad idea to use PayPal as our main payment processor…

Now in addition to all major credit cards, we accept Bitcoin as well.

As with any new things, there might be some things that need fixing. Please let us know if you notice anything.


See me at the Maker Faire Bay Area 2014

It’s that time of the year again. I’ve been working tirelessly preparing for Maker Faire Bay Area.
There will be a couple of new products introduced and on sale at special introductory prices!

Maker Faire website


R48 Battery Life Improved

After looking through the firmware very closely, I figured out a way to reduce power consumption of R48 via firmware tweaking. (Aggressive use of CPU “idle” mode while waiting for PWM pulse to output, etc.)

I managed to reduce the power consumption up to 43%. In my tests the batteries are lasting 50% or more longer!

All R48 will be shipped with the new, improved firmware as of today. If you already have R48, please send in for free upgrade.

How to receive the free firmware upgrade

  • Please send your R48 to the address below.
    The LED Artist
    12A Louis PL
    FL 2
    Brooklyn, NY 11233 USA
  • Send only the R48 unit, without batteries or chargers.
  • We will pay for the return postage. (Please pay for your postage to send in.)
  • Make sure to clearly indicate the return address.
  • The upgraded R48 will be sent back via USPS First Class mail.
  • Enjoy the longer battery life!

Aurora 9×18 mk2 kit Back in Stock


Aurora 9×18 mk2 kit & PCB are now back in stock!


More Products Available at Maker Shed

I’m so excited to announce that my wearable items – A12, R48 (all colors), and USB Li-Ion Charger are now available at Maker Shed!

You can find them here.

Maker Shed also sells Color Organ Triple Deluxe II and Colour Night Joule Thief Kit.


The LED Artist wearables at Adafruit

I’m very excited to announce that now some of my LED wearables are sold at Adafruit!

See the “New Products” video – my wearables are on at 13:35.


R48 Now Available in 4 Colors


R48 wearable LED accessory is now (finally!) available with 4 different color LEDs. In addition to blue, red, green and white LED versions are now available.

Thank you so much for waiting.

Purchase R48 here.


Limited Supply – Color Organ Acrylic Case

I have a limited supply of laser-cut acrylic case for Color Organ Triple Deluxe II available. This is one time offer, the cases won’t be available again once the supply is gone.
(The case kit does not include the knob.)


T962A Reflow Oven Hack Instructables

Recently purchased T962A reflow oven. There were a couple of issues that I dealt with. Please see the Instructable on what I did.

- See the Instructable


See You at the Maker Faire Bay Area


Hello West Coast! I will be exhibiting at the Maker Faire Bay Area on May 18 & 19th.

This is the largest of Maker Faire, so I will be bringing a lot of stuff, some of which are not yet seen by anyone. (yes I’ve been working hard)

Please come see me and hundreds of great makers at this event. It will be exciting!


Laser Cut Enclosure for Color Organ Triple Deluxe II

I made a laser cut acrylic enclosure for Color Organ Triple Deluxe II.

It’s a very simple design, but very functional. Built with laser cut acrylic and screws and nuts only. No filing, glueing or bending.
You can download the design file, and laser cut 3mm acrylic. I used Ponoko, but you should be able to use any services available.
Use my design as is, or customize as you like.
You will also need four 1 inch, #2-56 machine screws and nuts, such as these.

ColorOrganTripleDx2Enc-rev2.eps
* The design file is formatted according to Ponoko’s specifications. You might have to modify it if you are using a different service.


Through-hole only version of Audio Interface

The through-hole only version of Audio Interface is now available for Aurora 12 bar, Aurora 9×18 mk2 and Aurora 18×18.

Now those who are not into surface mount soldering can build Aurora color organ (or VU meter)!

The circuit is exactly the same as the original surface mount version of Audio Interface.

You can watch the video here.

The interface goes between the power cable and Aurora, using Molex 3 pin connectors. The interface has a 3.5mm stereo audio jack, so you can connect any audio output. There’s a potentiometer to adjust the sensitivity level as well.
Aurora 12 bar, Aurora 9×18 mk2 and Aurora 18×18 have audio or “color organ” modes, which you can select by either pushing the on board button or using a remote control (remote not on Aurora 12 bar).

> purchase the kit or PCB


International Shipping Fees Reduced

I revised the international shipping fees. The recent changes of postal fees made it very difficult to provide reasonable shipping fees to non-US customers. However I’ve signed up with a bulk mailing service, which made possible to reduce international shipping fees.

You will notice “International Economy” shipping option when you go through the checkout. The orders will be shipped via USPS First Class mail, which is very economical. Please note, however this option does not provide any tracking. If you want tracking and quicker delivery, please consider “International Express Air”. “International Priority Air” is quicker than Economy, but still doesn’t provide tracking…


Shipping Delay

Due to Hurricane Sandy, we are experiencing shipping delays. Our area did not get much damage, but postal service is not working.
I think everything will go back to normal in a couple of days.

*** UPDATE: We are back to normal. USPS is reporting normal delivery. ***


Wave JT Firmware Update

A new function has been added to Wave JT. It’s auto-changer or “demo” mode. With this mode activated, Wave JT will change the animation pattern every minute. (Hence the word demo.)

You can activate this new function by holding the button down at the startup (when power is off). After each of eight LEDs has lit once, all LEDs will blink eight times. If you release the button within this period, the demo mode will be activated.
Wave JT only keeps this setting until powered down, so to get out of demo mode, turn off the power, and tap on the button again to turn on the unit.

The kits are now being shipped with this new firmware.

- download wave_jt-1.1.hex (ZIP)


Come See Me at Maker Faire NY

World Maker Faire New York 2012

Please come see me at the Maker Faire NY this weekend.
I have some goodies for you! Mention this code: “LED fetish“, and you will get a freebie. I will have proto PCBs, assorted LEDs, and even working prototypes!

I will also sell my kits at discounted prices! Must come!

 

 

Update: I’m on the flyer!


Prototype PCB Giveaway!

As a part of developing new projects, I make PCBs for prototypes. I usually use OSH Park to have my prototype PCBs made. They are great – sophisticated web ordering page compete with full preview of the PCB design, which has helped me notice the errors before ordering. Low, no-gimmick pricing – just $5/sq. inch for a set of three PCBs.

Since I don’t always use all prototype PCBs, I have a few PCBs laying around. Some of them contain errors (that’s the point of prototyping, right?), but most of them (lucky for me) are perfectly functional.

So I want to give away those good prototype PCBs. The schematics and BOMs are provided on this site or instructables already, so you can gather parts and build them!

The qualification is simple – give me/my site a mention and a link on your web site, or if you have made any of my designs, put up a project at instructables (with pictures or/and video). Let me know what you did by either leaving a comment here or email, and I will send you a PCB. (Free shipping within USA only – sorry, international shipping will cost $5.)

I have more than a few good PCBs for the published and unpublished designs. Offer is limited to while PCBs last.

 


SMT Soldering 101

I get a lot of questions regarding surface mount soldering. The thing is, with the right tools and a bit of practice, SMT (Surface Mount Technology) soldering is really not difficult.

First, please view this excellent video created by CuriousInventor.com (no affiliation. I just like this video very much). I’ve been doing SMT soldering for a while now, but was very impressed with the techniques shown in this video.

Here’s the list of tools/material you need:

  • Temperature controlled soldering iron/station (such as Hakko FX-888. Standard size tip works fine.)
  • Thin soldering wire – 0.015 inch (0.4 mm)
    Regular 0.03 inch (1 mm) gauge solder wire is too thick for small SMDs. A very common problem with SMT soldering is to apply too much solder. Small parts like 0603 resister only need tiny amount of solder.
  • Flux – pen type flux such as Kester 951 recommended. Apply generously – it will dry out quickly and does not harm the PCB.
  • Tweezers with small tips – get a good pair that’s confortable to use.
  • Magnifying glass – you can’t solder if you can’t see. I wear magnifier visor (OptiVisor #4).
  • Good lighting – you need much brighter lighting then reading a book to see the small details of SMT soldering.
  • Solder wick – as excess solder is the enemy of good SMT soldering, you need solder wick to remove excess solder. Perfectly soldering fine pitch packages like QFP is very unlikely without a help of solder wick. Thinner one like 1.5 mm wide is easier to use.

Traditional through hole technology is phasing out, and so many new devices are not offered in through hole style. Learn to solder SMT will broaden your choices.

(Let me know if I forgot to add anything here.)

 


See You at the Maker Faire New York!

World Maker Faire New York 2012


I’m excited to announce that I will be participating in the upcoming Maker Faire New York! (Sep. 29-30 @ New York Hall of Science, Queens, NY)
Details are not yet known, but I will bring all of available products and possibly some unpublished prototypes. I will post more info as it develops.

Update: My booth will be in Zone A, nysci building.

See you there!


Universal LED Driver kits now sold by LEDsales

My Universal High-Power LED Driver kit is now being sold by LEDsales in Australia. If you live in Australia, you will save by lower shipping fees.

LEDsales has a lot of cool stuff to aid in your projects, so you should check it out.


New “Preprogrammed” PIC option for Aurora

I realize that many people just want to assemble Aurora kits without having to purchase a PIC programmer. Now I added options to have the PIC microcontroller preprogrammed when you purchase the kits.

Note: PIC IC will be soldered to the PCB in order to be programmed.

Aurora 9×18 mk2 Kit and PCB

Aurora 18×18 Kit and PCB

 


Firmware Updates to the New Auroras

Aurora 9×18 mk2 and Aurora 18×18 firmware has been revised to detect the Audio Interface connection at the start up. The Aurora’s will check to see if the Audio Interface is connected to them, and disable the color organ modes (there are two). Which means you don’t have to go through two empty program modes when pushing the button to change modes without the Audio Interface connected.