The LED Artist - blog » Battery

Pocket High Voltage Generator Upgrade

The LED Artist — Mon, 22 Oct 2018 02:16:47 +0000

HV Generator open output voltage – limited internally to under 200V. The red LED lit up to indicate the voltage limit has reached.

The Pocket High Voltage Generator that I made a few weeks ago proved to be a very handy tool. I have been testing Zener diodes very often since I use many Zeners in 12V to 91V range.

However I wanted to give it a bit more power so that I can test Nixie tubes clearly – the previous design can only give less than 0.5 mA through most Nixie tubes, some digits don’t lit up completely.

I made some upgrades to the components to give it a modest 2 – 5 mA (depending on the voltage) output. While still keeping the same form factor.

Upgraded HV Generator can comfortably drive Nixie tubes at 1 – 2 mA of current.

Now this circuit has enough oomph to shock you if you accidentally touch the output! Not the dangerous level, but it IS shocking. Perhaps one can use this as an electric Jack-in-the-box…

I’m sharing the PCB design of this project. Which can be purchased or downloaded via OSH Park.

Pocket High Voltage Generator Quick Build

The LED Artist — Thu, 04 Oct 2018 02:05:27 +0000

- There’s an update to this post, including PCB design files. -

There are times you find yourself looking for a relatively high voltage (100V to 200V often in my case) but low current DC power supply. I have zener diodes that are higher than 30V, which makes the lab supply useless, and filament LEDs with forward voltage over 60V. When I need to test them quickly, I used to hook up a simple rectifier circuit to a variable AC power supply (nothing more than a slidac with isolation transformer). While this gets job done, the setup is capable of supplying much too high current (1A or more), so I was always very nervous and extra careful in handling the circuit. All I need is a little HV generator that gives me around 200V DC and only capable of supplying a milliamp or less. Realizing that I do have such design available – one of the Nixie supply circuit – I just decided to put one together to use.

Pocket HV Generator schematics

Quick & dirty build of the tool.

A single AA battery seems to be enough to generate over 200V on the output with no load. But the output quickly lowers when you draw 0.4mA. So it feels pretty safe to handle this casually, and I can only feel a bit of tingling, not electric shock when I touch the output terminals. The tool proved to be quite handy and useful in testing variety of things:

Zener diodes (zener voltage)
Switching diodes (reverse breakdown voltage)
Filament LEDs (forward voltage)
Regular LEDs (forward voltage – yes it’s ok to use this tool, since it’ll only give less than 1mA even at 2-3V)
BJTs (breakdown voltages)
Neon & Nixie tubes (not very bright, but you can tell if one works or not)

Pocket HV Generator testing a zener diode

Pocket HV Generator testing a Nixie tube

This is one of the most useful tools that I’ve made. And it only took a couple of hours to put it together.

Mini Headphone Amp /w Bass Boost

The LED Artist — Wed, 19 Sep 2018 01:46:53 +0000

Added a new project to Instructables on headphone amp. This is something that I have made to improve my music listening experience during my subway commute.

- See the instructable

R48 Battery Life Improved

The LED Artist — Sat, 15 Feb 2014 03:36:21 +0000

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!

A12 – Wearable LED Gadget with Full-Color LEDs

The LED Artist — Wed, 02 Oct 2013 04:00:00 +0000

New addition to my wearable LED accessories is A12. A12 is the same size as R48, uses the same microcontroller and battery, but with 12 full-color LEDs. A12 produces patterns similar to Aurora mini 18, but lighter and has a built-in battery holder in the back.

A12 comes with a non-rechargeable battery (CR2450) and a black cord (lanyard) to hang around the neck. The battery lasts for about 5 hours or more in continuous run.

There are also rechargeable battery (LIR2450) and the charger available. With those, you won’t need to keep buying batteries.
The charger is very compact and plugs right into an USB port.

Features/Notes:

12 full-color LEDs produce beautiful colors.
A12 is available fully assembled or soldering kit.
Comes with a non-rechargeable battery (CR2450, easily replaceable).
Battery will typically last about 5 hours continuously.
Also comes with black cord (lanyard) to hang around your neck.
10 beautiful animation patterns preprogrammed.
“Demo” mode automatically runs though all animation patterns – changes every minute. (Activated by holding the button at the startup.)
Rechargeable battery (LIR2450) is also available as an option. This recommended option lights the LEDs brighter, as it has higher voltage.
The charger for the above is also available.
Dimension: 1.9 inch diameter, 0.4 inch thick (including the battery)

Technical Details:

12 common-anode RGB LEDs.
PIC24F08KL301 16 bit microcontroller @ 32 MHz.
Each LED is PWM controlled in 128 gamma-corrected levels.

- more technical info here.

In-stock and shipping now!

R48 and Li-Ion Charger

The LED Artist — Thu, 18 Jul 2013 21:35:24 +0000

R48 comes with a non-rechargeable battery (CR2450) and a black cord (lanyard) to hang around the neck. The battery lasts for about 7-8 hours in continuous run.

There are also rechargeable battery (LIR2450) and the charger available. With those, you won’t need to keep buying batteries.
The charger is very compact and plugs right into an USB port.

White LEDs look yellow when they are not lit. Other colors (red, green, and blue) look like the photo above.

Features/Notes:

Available with 4 different color LEDs: Red, Green, Blue, and White.
Each R48 is fully assembled, and comes with a non-rechargeable battery (CR2450, easily replaceable).
Battery will typically last about 7-8 hours continuously.
Also comes with black cord (lanyard) to hang R48 around your neck.
25 beautiful animation patterns preprogrammed.
“Demo” mode automatically runs though all animation patterns – changes every minute. (Activated by holding the button at the startup.)
Rechargeable battery (LIR2450) is also available as an option. This recommended option lights the LEDs brighter, as it has higher voltage.
The charger for the above is also available.
Dimension: 1.9 inch diameter, 0.4 inch thick (including the battery)

In-stock and shipping now!

R48 – an Wearable LED Gadget Pre-order Starts

The LED Artist — Sun, 30 Jun 2013 20:34:43 +0000

Here’s the sneak peak at the upcoming wearable piece – R48. (I promise that better video will come soon.) Four different LED colors (Red, Green Blue, and White) are planned, but the first color available would be blue.

The item will be in stock in the 3nd week of July, and the price will be $49. Pre-order starts now at $45 a piece.

Also available are optional rechargeable Lithium-Ion battery and the charger. The charger is very compact and plugs into an USB port. The photo below is showing the prototype. The final version will look better in black. (Will post the photo as soon as available.)

Features/Notes:

Each R48 will be fully assembled, and comes with a non-rechargeable battery (CR2450, easily replaceable).
Battery will typically last about 5 hours continuously.
Also comes with a black cord to wear R48 as a neckless.
25 beautiful animation patterns preprogrammed.
“Demo” mode automatically runs though all animation patterns – changes every minute. (Activated by holding the button at the start up.)
Rechargeable type battery (LIR2450) is also available as an option. This recommended option lights the LED brighter, as it has higher voltage.
The charger for the above is also available.
Dimension: 1.9 inch diameter, 0.4 inch thick (including the battery)

R48 is now shipping – pre-order is ended.

Battery Cases

The LED Artist — Fri, 12 Oct 2012 21:32:20 +0000

Here are handy battery cases for driving Aurora with batteries. These hold two, three, or four AA batteries, and has a power switch. The cords are terminated with a 2 pin Molex female connector (standard 2.54 mm pitch), so connecting to Aurora is a snap.

In general, Three batteries are recommended, but two Alkalines work ok (LEDs will not be as bright) with Aurora 12 bar or Aurora mini 18. For Aurora 9×18 and Aurora 18×18, use of four AA batteries is recommended.
Two AA battery configuration is only effective if you are using Alkaline batteries. Rechargeable batteries such as NiMH or NiCD have lower voltage, so at least 3 of them need to be used to power Aurora.

*** Purchase Here ***

Colour Night Joule Thief kit

The LED Artist — Fri, 24 Feb 2012 19:47:05 +0000

Colour(Color) Night Joule Thief kit and PCB are available. Please use the buttons below to purchase.

Detailed information and building instructions are here: http://www.instructables.com/id/Colour-Changing-Night-Joule-Thief/

*** Purchase Here ***

Night Joule Thief – LED Night Light Kit

The LED Artist — Mon, 05 Sep 2011 00:48:00 +0000

Joule Thief circuit is combined with an ambient light sensor – Night Joule Thief is a little night light that keeps going with just one battery for weeks! Two white LEDs light up surprisingly bright.

* This is the original version of Night Joule Thief that uses white LEDs – not to be confused with the new color changing version.

Please view the instructables for technical info and assembly steps.

*** NOTE: The color of the PCB will be green instead of purple shown in some of the pictures. ***

*** Purchase Here ***