Archive for August 2013

UPS Transfer Time Measurement

Most offline/line interactive UPS‘ (Uninterrupted Power Supply) have a transfer time between 5 to 15 milliseconds. In this post, I will show you the results of the measured switch-over performance of my APC Back-UPS XS1500 and the technique I used. Continue reading ‘UPS Transfer Time Measurement’ »

Tektronix 2213 Teardown Pictures

I love old Tektronix analog oscilloscopes and I could not seem get enough of them. So when I saw a cheap “untested, unknown working condition” Tektronix 2213 listed on eBay recently, I just could not resist the temptation to grab it. Continue reading ‘Tektronix 2213 Teardown Pictures’ »

Variable Power Regulator Using TPS5420

I typically use linear regulators (e.g. 7805, LM317, etc.) in my projects. Linear regulators (especially the low dropout ones) are great when the load is light and input/output voltage difference is small, otherwise you will need a big heatsink as significant amount of power is dissipated as heat. The heat issue was evident in my earlier build of the VFD clock. Given how easy it is to use a switching regulator nowadays, there really is no excuse to settle on a linear regulator in situations like this. Continue reading ‘Variable Power Regulator Using TPS5420’ »