Kerry D. Wong

I bought a USB wall outlet adapter recently so that I can free up my wall outlets while charging my phones and tablets. Of course, before putting it into use, I wanted to open it up to take a peak inside to see if it was properly engineered and at least to make sure that it would not be a safety hazard at the least. After all, this USB adapter is meant to be plugged in all the time. Continue reading ‘Teardown of an MVMT Dual USB Port Wall Outlet Adapter’ »

Recently I got hold of a dead APC SurgeArrest power strip that was about to be thrown out in my office. The power strip simply doesn’t provide power to any of its outlets regardless of the power switch position. Since there was no external fuse that I could find, I decided to take it apart and find out why and how it had failed. Continue reading ‘Unusual Failure Mode of an APC Surge Protector’ »

I just picked up a Keithley 775A programmable frequency counter from eBay. Specification-wise, this counter is very similar to the Racal Dana 1992 frequency counter I repaired last year. The Keithley 775A I got came with an additional channel (option 7751) and is capable of measuring frequencies up to 1.3 GHz. Continue reading ‘Keithley 775A Programmable Counter Teardown’ »

Although LED light bulbs have been around for a while, I have not been able to totally replace all my lights in the house to LED ones until quite recently. The main reason is that some of my existing light fixtures only take G16.5 style bulbs with E12 screws and higher wattage LED bulbs of this kind only became available until quite recently. Continue reading ‘Teardown of an EcoSmart 60W Dimmable G16.5 LED Bulb’ »

I recently bought an HP 8671A microwave frequency synthesizer on eBay. This synthesizer can generate signals from 2GHz to 6.2GHz with an unleveled output of more than 8dBm. It is a nice complement to my HP 8642B signal generator and Wavetek 907 signal generator. Using these generators, I can now generate signals of pretty much any frequencies under the 12GHz range. A video of this teardown is linked towards the end of this post. Continue reading ‘Teardown of an HP 8671A Microwave Frequency Synthesizer’ »

My video on the teardown of an HP 493A traveling wave tube amplifier had generated quite a bit of interest. After I revealed that the electron gun portion of the tube was radioactive, a couple of my YouTube channel viewers had wondered if I could take the traveling wave tube further apart. So I did just that. Continue reading ‘Further Disassembly of the HP 493A TWT’ »

I few months back, I wrote about my experience with the six dimmable Philips LED bulbs I purchased a year ago. Those light bulbs all failed within months of each other in just over a year of use. This time around though, it’s the Crees ones that had bit the dust. They lasted a few months longer and were among the twelve I originally purchased. So I decided to open up one to see how the Cree LED bulbs were constructed. Continue reading ‘Teardown of a 65W Cree LED Bulb’ »

I recently picked up a BK Precision 1696 programmable switching power supply off eBay. Unlike many of the vintage test equipment I did teardowns with in the past, this model is still in production today. The one I got was sold with a damaged LCD screen and thus I paid very little for it. Of course, a brand new one would cost around $300. Continue reading ‘Teardown of a BK Precision 1696 Programmable Switching Power Supply’ »

The last ingredient for my backup power project is an inverter. Since the battery bank I built is a 12V 1.5kWh one, an inverter that can handle a load between 500W and 1000W would be a suitable choice. In theory, all the lights and the refrigerator in my house consume just around 500W. So the 1.5kWh battery bank should be able to power all the essentials for at least a couple of hours in the event of a power failure. Continue reading ‘Teardown and Testing of an 800W PureSine Inverter’ »

I recently purchased a BSide ACM03 Plus clamp meter so that I could do some high current measurements for my tab welder project. This meter can be bought on eBay for around $25, which makes it one of the cheapest Hall effect clamp meters on the market that is capable of measuring both AC and DC current. Continue reading ‘BSide ACM03 Plus Clamp Meter Review and Teardown’ »

I just picked up another high voltage power supply, this time it is a working Bertan/Spellman 225-20R 20kV one. Unlike the Bertan 205A-05R that I did a teardown with last time which was entirely analog, this one can be controlled digitally either via the front panel or via GPIB from the back. In this blog post, let me share some of the teardown pictures with you. If you are interesting in seeing some cool experiments with this high voltage power supply, you can scroll down and watch my video towards the end. Continue reading ‘Bertan/Spellman 225-20R HV Power Supply Teardown’ »

I recently was given a broken Epson PowerLite 84 projector. The projector would not turn on when plugged in and there was no sign of life. So I decided to take a look at what was wrong with it. The potential reward is high since I do not have a projector yet and I could definitely use one for my home theater setup. A video of this teardown and repair is linked towards the end. Continue reading ‘Epson PowerLite 84 Multimedia Projector Teardown and Repair’ »

I bought a non-working Lambda LQ-521 linear power supply on eBay a couple of weeks ago. Usually I avoid knowingly buying something that is broken unless I am certain that I could obtain parts for it at a reasonable price. But buying broken linear power supplies is another story as most of the problem can be fixed with readily available components. Continue reading ‘Lambda LQ-521 Power Supply Teardown and Repair’ »

I did a teardown of an RSA SecurID many years ago (you can see that post here). In that teardown, it was an older generation (SD600) of the RSA SecurID. In this post, let’s take a look at what’s inside the newer SID700 series RSA SecurID token. A short video of the teardown is included towards the end. Continue reading ‘RSA SecurID Teardown’ »

I did a teardown video of a microwave range (8-10 GHz) RF isolator last week. As a follow up, I will post some of the high-resolution pictures I took during the process here (click to see larger images). Continue reading ‘Teardown of an 8-10 GHz RF Isolator’ »