Field-tested guides and free design tools for ELV engineers
CCTV, networking, fire detection and smart-building know-how written from real job sites, not datasheets. Plus free calculators to design faster.
Learning paths
Free step-by-step courses from a working ELV engineer. Follow a path in order, practise with the tools, and track your progress.
Browse by system
Pick the system you’re working on today.
Smart CCTV
IP vs analog, NVR storage, lens selection, installation and wiring.
Explore →Networking & LAN
Structured cabling, fiber, switches, PoE budgets and VLANs.
Explore →Fire Detection
Detector spacing, loops, panels and BS 5839 / NFPA 72 basics.
Explore →Smart Systems
Home and building automation, access control and integration.
Explore →Free engineering tools
Run them in your browser. No sign-up.
Storage & Bandwidth Calculator
HDD size, RAID and bitrate for mixed camera groups.
Open tool → CCTVFOV & Lens Calculator
Lens, pixel density and IEC 62676-4 / DORI levels.
Open tool → CCTVThermal Camera Calculator
Detection, recognition and identification ranges.
Open tool → CCTVFloor Plan Designer
Place cameras on your drawing with live coverage.
Open tool → CCTVCCTV Map Designer
Plan outdoor cameras on a satellite map.
Open tool → FIREFire Alarm Design Tool
Detectors, sounders, loops, battery and BOQ.
Open tool → FIREExit Plan Designer
Bilingual evacuation plans with signs and routes.
Open tool → NETWORKNetwork & CCTV Designer
Single-line diagrams with ping and link simulation.
Open tool → NETWORK · NEWPoE Budget Calculator
Check PoE switch budget, ports and class limits with cable loss
Open tool → POWER · NEWVoltage Drop Calculator (12/24 V DC & 230 V AC)
Cable voltage drop for fire alarm, CCTV, access control & 230 V feeds
Open tool → POWER · NEWUPS & Battery Backup Calculator
Fire alarm standby Ah (BS 5839-1/NFPA 72) and CCTV UPS runtime
Open tool → NETWORK · NEWFiber Optic Loss Budget Calculator
Fiber link loss, SFP/GPON power budget, margin, reach & overload check
Open tool → NETWORK · NEWIP Subnet & VLAN Planner
Subnet calculator plus VLSM VLAN plan for CCTV, access control and BMS
Open tool → NETWORK · NEWRack Layout & U Planner
Plan 19" rack U space, weight, power, heat and draw the elevation
Open tool → ACCESS · NEWAccess Control Designer
Doors, locks, readers, controllers, parking and interfaces with BOQ.
Open tool →Need a custom tool?
Tell me what you calculate by hand every week.
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ELV & security design support for your next project
From concept drawings to commissioning, get an engineer who has delivered CCTV, fire alarm, PA and network systems on real sites in Saudi Arabia and Africa.
Discuss your projectAbout me- 📐 System design & layouts (CCTV, fire alarm, PA/VA)
- 📋 BOQ, datasheet review and compliance checks
- 🔌 Network & fiber backbone planning
- ✅ Pre-commissioning and testing checklists
Hi, I’m Sarwar
Senior ELV & ICT project engineer. I write Techubox so technicians and engineers can skip the trial and error I went through on site. Read my story →
