June 18, 2017, 7:51 pm
I had wanted to make a spot welder for a while. Most of the DIY spot welders use a momentary switch the primary side of the microwave oven transformer (MOT). Due to the simplicity of this design, it is very simple to make. This design however, has some inherent safety issues as the momentary switch is typically within reaching distance of the operator (unless a foot switch is used) and inadequate insulation could increase electric shock risk. Further more, the current flowing through the primary winding can significantly exceed the current rating of the switch and cause the switch to fail. Due to the inductive nature of the winding, the switch can sometimes arc over and pose significant risk to the operator. Continue reading ‘Dual Purpose Spot Welder With Pulse Duration Control’ »
March 11, 2017, 8:31 pm
Last time, I did a teardown of the Datum 8040 Rudidium standard. As I discussed, the 8040 has a 1PPS output but the pulse width is very short, at around 20µs. In this blog post, let us take a look at how to extend this 20µs pulse to make the 1PPS output symmetrical. As usual, a video is included towards the end. Continue reading ‘Datum/Symmetricom 8040 Rubidium Standard Modifications’ »
December 24, 2016, 4:21 pm
In this blog post, I will show you a simple hardware hack to make your mouse capable of rapid firing (or automatic continuous clicking). Of course you can always resort to software mods to achieve the same goal, but admittedly doing so in hardware is nevertheless more fun and as a bonus you also get an extra button. A video demonstrating this hack can be found towards the end. Continue reading ‘Hacking Your Mouse for Rapid Firing’ »
June 5, 2013, 8:50 pm
I recently salvaged a vacuum fluorescent display (VFD) from a piece of old test gear. The VFD is a 13 digit 7-segment multiplexed display and I thought it would look great in a custom digital clock or something similar. While it has the model number FUTABA 13-MT-54NA, I could not find any information on the internet specifically for this model. Continue reading ‘VFD Filament Driver Using 555’ »
November 23, 2012, 8:21 pm
Simple slave camera flash (or synchronous flash, like this one I built earlier) works great with older film cameras, but does not work with modern digital cameras. This is due to the fact that the majority of the digital cameras nowadays employee a so-called pre-flash for metering purposes prior to the actual shooting. The pre-flash causes the slave flash to be triggered prematurely which inter has a detrimental effect on the picture taken, causing the scene to be darker then done without using the slave flash since the camera thinks the environment was lighter than it actually was when the slave flash was triggered. Continue reading ‘Advanced Slave Camera Flash Controller’ »
June 21, 2012, 6:39 pm
Last year, I wrote about a simple digital metronome project. While the device worked pretty well there are a few changes that are to be desired. Continue reading ‘Digital Metronome — Revisited’ »