Technical articles
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Relay, Transistor, or Triac? Understanding PLC Output Types with Live Circuit Diagrams
A lamp keeps glowing faintly after you switch it OFF. A transistor output dies the instant a solenoid valve is switched off. ── Pick the wrong PLC output type and strange things happen with nothing actually broken. This article sorts out relay, transistor, and triac outputs from a single viewpoint…
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Understanding PNP and NPN in Electrical Design with Live Circuit Diagrams
“I turned the output ON but the lamp never lights.” “We swapped a sensor and the PLC input stopped responding.” ── Most stumbles in control wiring begin with mixing up PNP and NPN; in other words, the direction of sink and source. Built around one idea ── NPN pulls current…
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Why Is the Office Network So Slow? A Practitioner’s Map of the Usual Suspects ── DNS, Broadcasts, VPNs, and Address Exhaustion
“The office network crawls every Monday morning” ― “everything slows down the moment I connect to the VPN” ― a slow company network has a cast of usual suspects, each defined by whether bandwidth, latency, or loss is the thing that’s clogged. This article maps the classic bottlenecks ― DNS,…
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What Happens Without a Firewall? The Era of “Infected Just by Connecting” and 5 Moments You’re Still Exposed
You boot a brand-new PC, and before the antivirus is even installed, you’re told to open a website to activate its license ── is that moment of going online “unarmed” actually dangerous? Starting from the mid-2000s era when PCs got infected within minutes of connecting, this article maps out what…
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Why Does a Restart Fix Things? A Visual Guide to How OS and Memory Management Really Work
Why does a restart often fix a sluggish PC or phone? Is “shut down then power on” really the same as “restart”? This beginner-friendly visual guide explains it through the lens of the OS and memory management — covering the memory hierarchy, process memory layout, the 8 phases of a…
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![How to Choose the Right SQL Numeric Type — INT, BIGINT, DECIMAL & FLOAT Explained [DB Design Guide]](https://toolcluster.app/wp-content/uploads/2026/08/sql-numeric-types-guide-en.png)
How to Choose the Right SQL Numeric Type — INT, BIGINT, DECIMAL & FLOAT Explained [DB Design Guide]
A practical guide to SQL numeric types: INT, BIGINT, DECIMAL, and FLOAT. Learn why FLOAT must never be used for money, when BIGINT is truly needed, and how to pick the optimal type for every column in your database.
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![Complete Guide to Industrial Communication Protocols [2026] — EtherCAT, PROFINET, Modbus, CAN & OPC UA Compared](https://toolcluster.app/wp-content/uploads/2026/08/industrial-communication-protocols-guide-en.png)
Complete Guide to Industrial Communication Protocols [2026] — EtherCAT, PROFINET, Modbus, CAN & OPC UA Compared
A comprehensive comparison of industrial communication protocols — EtherCAT, PROFINET, EtherNet/IP, Modbus, CAN/CANopen, and OPC UA. Covers strengths, weaknesses, use cases, and selection criteria from a practical engineering perspective, spanning fieldbus to Industrial Ethernet and information integration.
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Comparing 8 Python Web Communication Technologies — A Use-Case Guide
REST, WebSocket, gRPC, MQTT, SSE, Celery, requests, aiohttp — a hands-on comparison of 8 Python web communication technologies by use case, difficulty, and speed, with production architecture patterns.