Groundloop

Grounding and EMI

One of the most common direct coupled noise sources is when the ground which is being used for reference or return is not referenced to earth as expected. This is especially prevalent in sensitive high-gain circuits. Grounding and Shielding Existing Equipment – How to effectively minimize EMI issues when best practices are not available is

How to protect RS-232 serial connections

How to protect RS-232 serial connections article pointed me to a recent white paper from APC-Schneider Electric that explains specific power protection issues related to RS-232 cabling. The Protection of RS-232 Serial Connections document contends that the RS-232 port often represents the “Achilles heel” of computer installations which are otherwise well protected by UPS systems

PCB grounding

Board-level designers often have concerns about the proper way to handle grounding for integrated circuits (ICs) which have separate analog and digital grounds. Should the two be completely separate and never touch? Should they connect at a single point with cuts in the ground plane to enforce this single point or “Mecca” ground? How can

Resistance grounded laptop PSU output

I have one pretty new ACER 5552G laptop that cam with with Delta Electronics ADP-90CD D8 power supply that has grounding practice different from other laptops I have seen (normally grounded or floating): The power supply output (otherwise floating) – side seems to be connected to mains ground through 1 kohms resistance on the power

Isolated laptop power supply issues

I have earlier written about grounded laptop power supply problems. Other popular laptop power supply configuration used is floating output. There are power supplies without ground, for example some Apple laptops and many other brands. The power supplies where there is no ground on connection on the mains side are for sure built in this

Improved laptop grounding idea

Many laptops are pretty well known for having terrible audio interfaces. There are usually noise and grounding issues. A recent post Yet Another Dell Laptop Audio Grounding Problem blog posting documents a well known and horrendous audio problem found on many Dell laptops. I have faced similar noise problems also on other laptops as well.