Skip navigation
1 2 3 Previous

Gough Lui's Blog

116 posts
It wasn't long ago that I posted about saying "Hello" to FPGA thanks to a prize received from one of the many FPGA quizzes on element14. As it turns out, the random number generator must have been smiling down at me because I was selected as yet another prize-winner for the FPGA Technology Quiz. As someone who visits the community on a regular basis, the surprise was spoiled as others living closer to the USA seemed to have received their parcels earlier ... mine only arrived on Friday. The b ...
When I hear the word "hello", my mind immediately thinks of three things - the greeting "hello", the first program one would probably write - "Hello, world!" and perhaps the Japanese fictional character, "Hello Kitty".   Perhaps now, I can add one more to the list - the Microchip Hello FPGA Kit. As part of my participation in the element14 Community, I took the FPGA Developer Quiz and thought nothing of it. A few weeks afterwards, I received a message from danzima asking me for my mailing ...
It’s been a great journey reviewing the Aim-TTi QPX750SP 750W Programmable DC Power Supply so far, but wouldn’t it be nice to end it all with a peek under the covers? After all, I don’t see any warranty void seals and the fuse is inside the cover, so I suppose it couldn’t hurt …   Peeking Under the Covers Removing just two screws on the back allows for the top cover to come off, which is nice and convenient. My first impressions are that of amazement – ...
The most important part of an instrument is how well it performs. This section covers some tests done using other benchtop equipment to try and characterise the performance of the QPX750SP. As the power envelope of the QPX750SP far exceeds most of my equipment’s capabilities, tests in this section were performed at set-points below the maximum capabilities of the QPX750SP and represent the operational characteristics across a common-range across the equipment involved. Unfortunately, this ...
Being the fortunate recipient of a 750W power supply, I thought it would be a shame if it were not given a chance to stretch its legs. It wasn’t originally part of my RoadTest proposal, but it seemed essential enough that I decided to spend just a little extra to make sure I could push the unit to its limits.   Testing a 750W Monster … The headline figure for the QPX750SP is indeed its 750W power rating, but how can one actually test this? Ideally, this would be tested using a ...
As the QPX750SP has an extended voltage range capability that reaches 80V, a key application would be to test telecommunications-based equipment which may be 48V nominal, but require voltages up to 60V to properly test. Initially, I thought I would test some 48V DC-to-DC modules, but having tested them before, their low power rating was perhaps problematic. As a result, I decided that I would try to measure the efficiency of the Microchip PoE-to-USB-C PD Adapter that I recently RoadTested. Unfor ...
When it comes to high-current requirements, the first thing that comes to my mind is testing MOSFETs. Ever since I received a batch of counterfeit MOSFETs, I’ve delved down into the rabbit-hole of testing MOSFETs under quasi-realistic application scenarios, chasing ever-more exotic parts that promise lower Rds(on) figures and compact surface-mount footprints. Unfortunately, only having a partially-functioning Rohde & Schwarz HMP4040 power supply, I could only really muster up 30A which ...
In this chapter, I will be looking at the various remote interfaces and PC connectivity options, including their latest Test Bridge software which was still in Beta/Release Candidate stage of development at the time of review.   PC Connectivity The Aim-TTi QPX750SP offers USB and Ethernet (LAN-LXI) as standard with GPIB available as an option. Unlike other models in the line-up, RS-232 (Serial) is not offered. The philosophy of the QPX750SP seems to be to keep things simple. As a result, ...
This chapter will examine the QPX750SP’s user interface and menus, provide some of my thoughts about the bench-top user experience and evaluate the documentation provided by Aim-TTi to support users.   User Interface & Menus Turning on the unit on, we are greeted a logo splash screen and a loading bar as it boots up. The time from flipping the switch to reaching the home screen is almost exactly ten seconds, which is relatively quick compared to other instruments with graphical ...
This post will focus on the unboxing process, showing the product from all sides and any included accessories. Unboxing The power supply is packed in an ordinary plain brown cardboard box. If it were not for the labels on one end, I wouldn’t even know what was inside. In our case, it seems that the QPX750SP inside is intended for the UK or European market, but since it was to be shipped out from the US, they also added in a 15A rated US mains lead. Opening the box, the power supply is ...
In this section, I will examine the key features of the Aim-TTi QPX750SP and ascertain its value for money by comparing its capabilities and price with similar products on the market.   Feature Introduction Aim-TTi are perhaps not as widely known as the “big name” instrument brands, however, they have been in the market of making test equipment since the 1970s initially as part of Sinclair Radionics which was renamed Tandar Electronics in 1980s which merged with Thurlby Electron ...
It has been a while since my last update for my Keithley 2450 SMU RoadTest, however, it seems that there have been some relatively-recently released improvements to the firmware and KickStart 2 software which are worth noting. While I was aware of these updates a little earlier, I've been quite busy (as has the SMU) so I didn't have an opportunity to apply the updates and evaluate them until now. As a result, I decided to write this "short" blog post to cover these changes.   Firmware Updat ...
It’s the holiday season – traditionally a time for reflection and being thankful for our blessings. Around element14, there are plenty of reasons to be thankful – a community of mostly like-minded professional engineers, mentors, hobbyists, tinkerers and enthusiasts backed by a multi-national electronics component distributor and services firm. In return, we are blessed with a lot of opportunities including design challenges, Project 14 and especially the coveted RoadTest progr ...
While the last section looked at MOSFETs, this final section will cover some of the results from my experiments on lighting technologies. The first section will look at the humble NE-2 neon indicator bulb and trying to build a nice I-V curve from actual data. The next section will explore the possibility of running conventional mains-powered light globes from high voltage DC – something that is not ordinarily done. I will also check out the transient performance of the 2450 – a set o ...
As one of the fortunate members to be selected to RoadTest the Keithley 2450 SMU, I delivered a review earlier this year with a significant caveat as a hardware issue stopped me from being able to perform some of the experiments I had initially planned. Following on from my series of follow-up posts comes this instalment which fittingly comes back full-circle to the experiment which led me to the discovery of the hardware issue in the first place.   Source-Measure Units, or SMUs for short, ...