Electronics Design

Ethernet measurements

Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Most commonly standards use 8P8C modular connectors (often called RJ-45), and supported cable standards range from Category 3 to Category 8. These cables typically have four pairs of wires for each connection, slower standards (10M and 100M) used only

Dynamic random flip memory

Row hammer (also written as rowhammer) is a security exploit that takes advantage of an unintended and undesirable side effect in dynamic random-access memory (DRAM) in which memory cells interact electrically between themselves by leaking their charges, possibly changing the contents of nearby memory rows that were not addressed in the original memory access. The

Ancient “fake RJ-45″

Who invented that and decided that it was a good idea to start to use this 10 pin RJ-45 look-alike connector? I wanted to do measurement with multimeter on UTP wiring, took a cable (left) that looked like RJ-45, but nothing worked as planned with it. Ended up butchering a real CAT6 cable (on right)

MTester LCR-T4 12864 LCD

One day I got a cheap MTester from some Chinese source. MTester is a cheap electronics component measurement device. It can detect component types and measure them. The meter has automatic detection PNP and NPN type bipolar transistors , N, P -channel MOSFET, JFET FET , diodes , two diodes, thyristors , resistors , capacitors

RLC measurements

This article is about measuring resistance, capacitance and inductance. The measurements described here talks about measuring components that not wired into any circuit. Resistors, Inductors and Capacitors are the most commonly used passive components in almost every electronics circuit. Out of these three the value of resistors and capacitors are commonly marked on top of

Mains LED waveform

I saw a quite interesting looking waveform from a 10W LED floodlight powered from 230V AC. It looks like when AC voltage waveform instantaneous voltage lower than some voltage, it takes practucally no current and above it it looks like a constant current load. This is picture of the light. This looks like this uses

Lutron LCR-9063

I bought a Lutron LCR-9063 meter long time ago (expect around 20 years or more) to be able to measure value of coils and capacitors. I has worked well for me. What looks like the same meter are sold as VOLTCRAFT LCR-9063 Component tester. This meter is designed for measuring resistance, inductance and capacitance. LCR-9063

ATX12VO STANDARD

The venerable ATX standard was developed in 1995 by Intel. It uses a power supply with many output voltages to motherboard. Ever since the original ATX PSU standard, the improvements have been gradual and never disruptive. Intel has been feeling some years that it is time to update the way PC motherboards. Starting in 2019,

BC547 and 2N3904 transistors

They are Bipolar Junction Transistor. Both are NPN Transistors. Their difference is manufacturer and hFE and datasheet parameters, seriously. BC547 is European transistor while 2N3904 is American transistor. Both are common NPN bipolar junction transistors used for general-purpose low-power amplifying or switching applications. https://en.wikipedia.org/wiki/2N3904 The BC548 was released with, and often is found together in