Category Archives: Soldering

Heater PWM Modification

Here’s a small weekend project that I worked on to address a few small annoyances that I had with my Presto HeatDish Parabolic Heater. The goal here was to replace the internal temperature regulator with a solid state relay driven with a variable frequency PWM signal for faster switching frequency, improved control sensitivity, and wider operating range while maintaining existing safeguards such as tip over and overheating protection.

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Nixie Tube Clock

Design files for this project can be found here (board + firmware), here (3D model).

Ever since I started dabbling in electronics, I’ve wanted to build myself a Nixie tube clock completely from scratch. Building one isn’t easy though given the various barriers to entry: the high cost of Nixie tubes ($10-$50 each), high voltages for driving the tubes (~170V+), designing the PCB, the desire for an nice enclosure that isn’t 3D printed or made out of laser cut acrylic, etc. All together, it meant that I didn’t have the time, knowledge, or resources for this project until now.

In order to increase the probability that this project reaches completion, the feature list was kept as low as possible while still aiming for a working clock that I can build upon in future iterations. As such, the Nixie tubes themselves must be easy to source, which rules out expensive and/or rare tubes that are difficult to come by. The goal of this project is to create a basic clock, so only four digits are needed along with a digit separator. The power supply must be efficient, and should be powered off of USB-C if possible. Being a clock, RTC functionality along with the ability to keep time even when disconnected from power will naturally be required. Finally, the enclosure must be well designed, heavy, and preferably machined out of stainless steel, copper, or brass.

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3D Printed Precision Paste Dispenser

Design files for this project can be found here.
3/16/2015 – Revision C update
6/25/2015 – Download link for my custom software added

Here is a design for a precision paste dispenser that I’ve been working on for the last few months. The goal of this project was to build a solder paste dispenser with a focus on consistent performance, 3D printable design, and minimal use of extraneous parts. While other designs exist (see here, here, here, here, or here), none of the existing designs are capable of low-volume paste dispensing at a consistency required for surface mount parts. These existing implementations are inherently limited by their design: they all use basic pneumatic or belt driven systems that simply don’t offer enough control. Commercial solutions certainly exist (see the Nordson’s EFD series, Fisnar’s PDV-1000 and RV5000DPM, IntelliSpense’s Auger Valve system, Techcon System’s TS7000, and Nordson ASYMTEK Spectrum II) but they usually run well into thousands of dollars ($5k+) for a basic system.

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NeoPixel Clock

The latest code base for this project can be found here

Here’s a quick weekend project that I did a week or so back. I decided to put together a standalone wall clock using Adafruit’s 60 NeoPixel ring, a ChronoDot real-time clock (RTC), TSL2561 light sensor, and a PIC12F1840 to tie everything together. The hardware was pretty straightforward, but the interesting part about this project was really with the one-wire protocol used to control the NeoPixels.

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Interactive Companion Cube

The latest code base for this project can be found here
Video and pictures are at the bottom of the post!

So I wanted to give a friend the 3D printed companion cube as a birthday gift, but I figured that just the cube by itself would be rather boring. Instead, why not add some audio functionality to the cube to make it a bit more impressive? And so I did. As I came up with this project idea only three weeks before the deadline, I was in a bit of a rush to get things working. As such, designing and ordering a custom PCB was out of the question. Instead of using a custom PCB, I came up with a stacking design using Adafruit’s perma-protoboards that would fit inside of the cube’s frame while still allowing enough real estate for all the components. As the frame was slightly smaller than the protoboards, I had to file the edges of the protoboards down a bit to get them to fit. The upside to this design was that I was able to achieve an extremely snug fit that should be pretty resistant to drops.

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