3D Print an HV Connector
In one of my previous posts, I did a teardown of a Bertan 225-20R high voltage power supply, which is capable of outputting 1mA with an adjustable voltage range up to 20 kV. The power supply came with a special…
Category: Miscellaneous
Miscellaneous
Adding Strain Relief to an Existing cable
Not all cables have proper strain relief built to the connector ends. This is particularity true for some of the iPhone 6 USB to Lightning™ cables. Take this Anker branded iPhone cable for example, after several months’ normal use the…
DTM0660 Datasheet Translated
I have received quite a bit of positive feedback since I wrote about the hacks on DTM0660L based multimeters last time. So I went ahead and translated the original Chinese datasheet into English and the PDF datasheet is linked below:
The Spectrums of Three Cheap Laser Pointers
A couple of months ago, I converted my EP200Mmd monochromator into a scanning monochromator and tested the spectrums of quite a few light sources. This time, I will take take a look at the spectrums of three cheap eBay laser…
Building A Laser Oscilloscope
You can generate some pretty amazing patterns by shining a laser onto a mirror mounted on a vibrating speaker cone, a lot of people have experimented with this kind of laser show. But how about building a true laser oscilloscope…
An Old Tung-Sol Germanium Transistor
I recently bought a few old power transistors from eBay. These are PNP Tung-Sol germanium transistors. According to the date code (6326) these transistors were made back in 1963, long before I was born. The last time I actually used…
Server Moved to Linode
I just moved my site from my own server to linode‘s VPS hosting. So you should see some pretty significant performance improvement down the road.
Peltier Cooler Module Repair
I bought a couple of Peltier cooler modules on eBay a while ago for some experiments. Of course, as I expected the quality of those cheap modules were pretty poor. After a couple of hours of continuous operation, both modules…
QFN Soldering Using SchmartBoard
I wrote a tutorial a while ago on how to hand solder fine pitched LGA/QFN chips using perfboards. While The technique illustrated works well with low pin count chips, for many people it is still a rather daunting task to…
Westinghouse L2410NM LCD Power Supply Repair
My seven year old 24 inch LCD monitor (Westinghouse L2410NM) started to flicker recently, so I decided to take a look inside to see what was wrong. Even before I opened it up, I had a pretty good idea of…
Tektronix 2445 Teardown
I bought an old Tektronix 2445 150 Mhz oscilloscope on eBay the other day. It was listed under “For Parts/Not Working” condition. Since the pictures in the auction listing suggested that the scope powers up and shows traces on all…
A Bidirectional Level-Shifting Buffer for Raspberry Pi
The current sourcing/sinking capability of the I/O pins on Raspberry Pi is quite limited. According to the Wiki page, the current limit for each I/O block (e.g. GPIO0 through GPIO27 combined) comes at only 26 mA maximum, which is only…
BK 4011 Function Generator Teardown
I got a used BK Precision 4011 5MHz function generator recently. The 4011 model is rather old and this particular unit was manufactured back in 1996. But BK precision still makes a similar model (4011A) which is identical to the…
Adding a Barrel Jack And a Switch to Raspberry Pi
I got myself a Raspberry Pi (Model B V2) last month. After having played with it for a while, I have to say that I really like this tiny single-board computer. Since it runs on Linux, you can compile and…
100K 5% Carbon Film Resistor Value Distribution
It is well understood that resistors are typically binned in such a way that for a given tolerance the actual resistance values are distributed within the specified tolerance but are outside the range of the next tighter tolerance specification. So…