Find and identify standardized electrical and electronic symbols according to IEC 60617. Includes power sources, resistors, capacitors, diodes, transformers, relays, switches, and more. Essential for reading circuit diagrams, drawing schematics, and engineering education. "An electronic symbol is a pictogram used to represent various electrical and electronic devices or functions in a schematic diagram of an electrical or electronic circuit." — According to IEC 60617 What Are Electrical Symbols? Electrical symbols are pictograms that represent components and functions in circuit diagrams. They allow engineers, technicians, and designers to: Communicate circuit designs clearly Understand complex systems quickly Create and interpret wiring diagrams Ensure consistency across industries and countries These symbols are defined by IEC 60617, the global standard for graphical symbols in electrical technology. Why IEC 60617 Matters IEC 60617 ensures: Universal understanding — same symbols worldwide Clarity and safety — prevents misinterpretation Interoperability — supports global design collaboration Compliance — required in many industrial and commercial applications Common Electrical Symbols & Their Meanings Symbol Reference Table Symbol Component Description Power Source / Battery Represents DC voltage source; positive (+) and negative (-) terminals indicated AC Supply Alternating current source (e.g., mains power) Resistor Limits current flow; labeled with resistance value (e.g., 1kΩ) Capacitor Stores electrical energy; polarized (electrolytic) or non-polarized Inductor / Coil Stores energy in magnetic field; used in filters and transformers Diode Allows current in one direction only; arrow indicates forward direction LED (Light Emitting Diode) Special diode that emits light when current flows Lamp / Bulb Represents lighting load Transformer Changes AC voltage levels between primary and secondary windings Switch Controls circuit continuity; can be open or closed Relay Electrically operated switch controlled by coil Ground Connection to earth or reference potential Fuse Protects circuit from overcurrent; breaks if current exceeds rating Circuit Breaker Automatically interrupts fault current; resettable Fuse Holder Enclosure for fuse; may include indicator Terminal Block Point where wires connect; often used in control panels Motor Rotating machine driven by electricity Integrated Circuit (IC) Complex semiconductor device; multiple pins Transistor (NPN/PNP) Amplifier or switch; three terminals (Base, Collector, Emitter) How to Use This Guide This web-based reference helps you: Identify unknown symbols in schematics Draw accurate circuit diagrams Learn standard notation for exams or projects Improve communication with electricians and engineers You can bookmark this page or save it offline for quick access during work or study.

Calculate electrical resistivity and conductivity of copper, aluminum, silver, gold, and iron at different temperatures using IEC 60028 and IEC 60889 standards. Includes temperature dependence formula ρ(T) = ρ₀[1 + α(T-T₀)] for accurate material modeling in power systems, motors, and PCBs. "Calculation of the resistivity and conductivity of a material based on temperature. Resistivity strongly depends on the presence of impurities in the material. Copper resistivity according to IEC 60028, aluminium resistivity according to IEC 60889." Parameters Resistivity Electrical resistivity is a fundamental property of a material that measures how strongly it resists electric current. Conductivity Electrical conductivity is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. Temperature coeff. Temperature coefficient of resistance for the conductor material. Temperature Dependence Formula ρ(T) = ρ₀ [1 + α (T - T₀)] Where: ρ(T): Resistivity at temperature T ρ₀: Resistivity at reference temperature T₀ (20°C) α: Temperature coefficient of resistance (°C⁻¹) T: Operating temperature in °C Standard Values (IEC 60028, IEC 60889) Material Resistivity @ 20°C (Ω·m) Conductivity (S/m) α (°C⁻¹) Standard Copper (Cu) 1.724 × 10⁻⁸ 5.796 × 10⁷ 0.00393 IEC 60028 Aluminum (Al) 2.828 × 10⁻⁸ 3.536 × 10⁷ 0.00403 IEC 60889 Silver (Ag) 1.587 × 10⁻⁸ 6.300 × 10⁷ 0.0038 – Gold (Au) 2.44 × 10⁻⁸ 4.10 × 10⁷ 0.0034 – Iron (Fe) 9.7 × 10⁻⁸ 1.03 × 10⁷ 0.005 – Why Impurities Matter Even small amounts of impurities can increase resistivity by up to 20%. For example: Pure copper: ~1.724 × 10⁻⁸ Ω·m Commercial copper: up to 20% higher Use high-purity copper for precision applications like power transmission lines. Practical Use Cases Power Line Design: Calculate voltage drop and select wire size Motor Windings: Estimate resistance at operating temperature PCB Traces: Model thermal behavior and signal loss Sensors: Calibrate RTDs and compensate for temperature drift

Technical pinout reference for RJ connectors: RJ-11 (6P2C), RJ-14 (6P4C), RJ-25 (6P6C), RJ-48 (8P8C), and RJ-9 (4P4C). Includes color codes, tip/ring assignments, and applications for telephony, T1/E1, and handset wiring. RJ-48 – E1 and T1 Plug (8P8C) Connector Type: 8P8C (8 positions, 8 conductors) Color Code: Orange, Green, Blue, Brown, White, Black Application: Used in digital telecommunications for T1/E1 lines in carrier networks and PBX systems. Pin Functions: Each pair (1–2, 3–4, 5–6, 7–8) carries a separate tip and ring signal for high-speed data or voice channels. Standard: ANSI/TIA-568-B RJ-25 – 6P6C Plug Connector Type: 6P6C (6 positions, 6 conductors) Color Code: White, Black, Red, Green, Yellow, Blue Application: Designed for multi-line telephone systems supporting up to three independent phone lines. Pin Functions: Pairs (1–2), (3–4), and (5–6) each carry a separate line (Tip/Ring). Usage: Found in business telephony and legacy PBX installations. RJ-14 – 6P4C Plug Connector Type: 6P4C (6 positions, 4 conductors) Color Code: White, Black, Red, Green Application: Used for dual-line residential or office telephones. Pin Functions: Pins 1–2 for Line 1 (Tip/Ring), Pins 3–4 for Line 2 (Tip/Ring). Note: Compatible with standard RJ-11 jacks when only one line is used. RJ-11 – 6P2C Plug Connector Type: 6P2C (6 positions, 2 conductors) Color Code: White, Red Application: The most common connector for single-line analog telephone service worldwide. Pin Functions: Pin 1 = Tip (T), Pin 2 = Ring (R) – carries the voice signal and power for the phone. Compatibility: Widely used in home phones, fax machines, and modems. RJ-9 – 4P4C Plug (Inside the Handset) Connector Type: 4P4C (4 positions, 4 conductors) Color Code: Black, Red, Green, Yellow Application: Connects the handset to the telephone base, carrying microphone and speaker signals. Pin Functions: Pin 1 (Black): Ground / MIC return Pin 2 (Red): Microphone (MIC) Pin 3 (Green): Speaker (SPKR) Pin 4 (Yellow): Ground / SPKR return Internal Circuit: Often includes a ~500Ω resistor between MIC and SPKR to prevent feedback oscillation.

Standard SIM card pinout for mini, micro, and nano variants (ISO/IEC 7816). Includes pin functions: VCC (power), GND, I/O (data), CLOCK, RESET, and reserved pins. Essential for embedded design, mobile hardware development, and SIM interface troubleshooting. Sim Card ┌─────────────┐ │ 1 5 │ │ 2 6 │ │ 3 7 │ │ 4 8 │ └─────────────┘ Connector at the card Pin Configuration & Description Pin Description 1 [VCC] +5V or 3.3V DC power supply input Provides operating voltage to the SIM chip. 2 [RESET] Card reset, used to reset the card's communications (optional) Sends a reset signal to restart communication protocol. 3 [CLOCK] Card clock Synchronizes data transfer between the mobile device and SIM card. 4 [RESERVED] AUX1, optionally used for USB interfaces and other uses Not used in standard GSM/UMTS/LTE SIMs; reserved for future or specialized applications. 5 [GND] Ground Common ground reference for all signals. 6 [VPP] +21V DC programming voltage input (optional) Used during manufacturing to program the SIM chip; not active in normal operation. 7 [I/O] Input or Output for serial data (half-duplex) Bidirectional data line for exchanging information between the phone and SIM. 8 [RESERVED] AUX2, optionally used for USB interfaces and other uses Reserved for future use or special applications such as smart card emulation.

Complete USB pinout reference for Type-A, B, Micro, Mini, and USB-C connectors across USB 2.0, 3.0, and 3.1 standards. Includes signal functions, color codes, Vbus, D+/D-, TX/RX, CC, SBU, and design tips for engineers. Based on USB-IF specifications. "Comprehensive pinout diagrams and technical descriptions for all major USB connector types, including Standard-A, B, Mini, Micro, and USB-C." This web-based reference provides a detailed breakdown of USB connector pin configurations, signal functions, voltage levels, and color coding across generations: USB 2.0, USB 3.0, and USB 3.1 (Type-C). All information follows official specifications from the USB Implementers Forum (USB-IF). Ideal for engineers, technicians, hobbyists, and students working with embedded systems, DIY electronics, or device repair. What Is USB? Universal Serial Bus (USB) is a standardized interface for connecting peripherals to computers and mobile devices. It supports: Data transfer Power delivery (up to 240W in USB PD) Device charging Hot-swapping Each USB version introduces new features: USB 2.0: Up to 480 Mbps USB 3.0: Up to 5 Gbps USB 3.1 Gen 2: Up to 10 Gbps USB 3.2 / USB4: Up to 40 Gbps The physical connectors vary by type and generation, but all follow strict pin assignments. USB Connector Types Overview Connector Pins Use Case USB 2.0 A/B 4 pins Hosts, printers, keyboards Mini/Micro USB 2.0 5 pins Older phones, cameras USB 3.0 A/B 9/11 pins High-speed data, external drives Micro USB 3.0 10 pins Smartphones, tablets USB 3.1 C (USB-C) 24 pins Reversible, high-power, fast data Note: USB-C supports reversibility, dual-role operation, and Power Delivery (PD). USB 2.0 – Standard A & B Connectors Standard A: Standard B:┌─────────┐ ┌─────────┐│ 4 3 2 1 │ │ 1 2 │└─────────┘ └─────────┘ ↑ ↑ Plug View Plug View Pin Configuration (4-Pin) Pin Signal Color Code Function 1 VCC (+5V) Red Power supply (up to 500mA) 2 Data - (D-) White Differential data pair (-) 3 Data + (D+) Green Differential data pair (+) 4 Ground Black Signal and power return Full-duplex communication using differential signaling No ESD protection on host side? Use TVS diodes! Mini/Micro USB 2.0 – Standard A & B Standard A: Standard B:┌───────┐ ┌───────┐│ 1 2 3 4 5 │ │ 1 2 3 4 5 │└───────┘ └───────┘ Pin Configuration (5-Pin) Pin Signal Function 1 VCC (+5V) Power supply 2 Data - (D-) USB 2.0 data negative 3 Data + (D+) USB 2.0 data positive 4 None Host detection: connected to ground in hosts, open in devices 5 Ground Common ground Pin 4 enables automatic detection of host vs. slave Used in older smartphones, GPS units, and digital cameras USB 3.0 – Standard A & B Connectors USB 3.0 A (9-Pin) Plug View:┌─────────────┐│ 5 6 7 8 9 ││ 4 3 2 1 │└─────────────┘ Pin Signal Function 1 VCC (+5V) Power supply 2 D- USB 2.0 data negative 3 D+ USB 2.0 data positive 4 GND Power ground 5 RX2- USB 3.0 receive line (-) 6 RX2+ USB 3.0 receive line (+) 7 GND Signal ground 8 TX2- USB 3.0 transmit line (-) 9 TX2+ USB 3.0 transmit line (+) Backward compatible with USB 2.0 Speed: Up to 5 Gbps (SuperSpeed) USB 3.0 B (11-Pin) Plug View:┌─────────────┐│ 9 8 7 6 5 ││ 10 11 ││ 4 3 │└─────────────┘ Pin Signal Function 1 VCC (+5V) Power supply 2 D- USB 2.0 data negative 3 D+ USB 2.0 data positive 4 GND Power ground 5 TX2- USB 3.0 transmit line (-) 6 TX2+ USB 3.0 transmit line (+) 7 GND Signal ground 8 RX2- USB 3.0 receive line (-) 9 RX2+ USB 3.0 receive line (+) 10 DPWR Power provided by device (e.g., bus-powered hub) 11 GND Return for DPWR Rarely used; replaced by USB-C in modern devices Micro USB 3.0 (10-Pin) Plug View:┌─────────────────────┐│ 1 0 9 8 7 6 ││ 5 4 3 2 1 │└─────────────────────┘ Pin Signal Function 1 VCC (+5V) Power supply 2 D- USB 2.0 data negative 3 D+ USB 2.0 data positive 4 ID OTG identification (host/device role) 5 GND Power ground 6 TX2- USB 3.0 transmit line (-) 7 TX2+ USB 3.0 transmit line (+) 8 GND Signal ground 9 RX2- USB 3.0 receive line (-) 10 RX2+ USB 3.0 receive line (+) Used in early smartphones and tablets before USB-C adoption Supports On-The-Go (OTG) mode USB 3.1 Type-C (24-Pin) – Reversible Connector Plug View (Top Side):┌────────────────────────────┐│ 1 2 3 4 5 6 7 8 9 10 11 12 │└────────────────────────────┘│ 13 14 15 16 17 18 19 20 21 22 23 24 │└────────────────────────────┘ Pin Configuration (24-Pin) Pin Signal Function 1 GND (A1) Ground 2 TX1+ (A2) SuperSpeed transmit (+) 3 TX1- (A3) SuperSpeed transmit (-) 4 Vbus (A4) +5V power supply 5 CC1 (A5) Configuration Channel (detects orientation, power roles) 6 D+ (A6) USB 2.0 data positive 7 D- (A7) USB 2.0 data negative 8 SBU1 (A8) Sideband use (for video/audio, alternate modes) 9 Vbus (A9) +5V power supply (second path) 10 RX2- (A10) SuperSpeed receive (-) 11 RX2+ (A11) SuperSpeed receive (+) 12 GND (A12) Ground 13 GND (B12) Ground (symmetric side) 14 RX1+ (B11) SuperSpeed receive (+) 15 RX1- (B10) SuperSpeed receive (-) 16 Vbus (B9) +5V power supply 17 SBU2 (B8) Sideband use 18 D- (B7) USB 2.0 data negative 19 D+ (B6) USB 2.0 data positive 20 CC2 (B5) Configuration Channel (backup) 21 Vbus (B4) +5V power supply 22 TX2- (B3) SuperSpeed transmit (-) 23 TX2+ (B2) SuperSpeed transmit (+) 24 GND (B1) Ground Fully reversible plug Dual-role data flow (host/device) Supports USB Power Delivery (up to 240W) Supports DisplayPort and HDMI via Alternate Mode Design Tips for Engineers Always route D+/D- as differential pairs with controlled impedance (~90Ω) Keep Vbus trace short and wide for better current handling Use TVS diodes on D+/D- lines for ESD protection Add pull-up resistors on CC pins for proper negotiation Follow USB-IF compliance guidelines for certification Standards Compliance USB 2.0: USB-IF Specification 2.0 USB 3.0: USB 3.0 Specification (Rev. 1.0) USB 3.1: USB 3.1 Specification (Rev. 1.0) USB-C: USB Type-C Specification (Rev. 2.1) All modern devices must comply with these standards for interoperability.

Calculate the economic transformer capacity (kVA) that minimizes total cost—balancing investment and losses—using GB 50052 standards. Ideal for industrial, commercial, and renewable energy projects. What Is Economic Transformer Capacity? In power system design, the economic transformer capacity refers to the rated capacity that minimizes the total cost—balancing initial investment and long-term operational losses—while meeting load requirements. Oversizing increases equipment cost and no-load losses; undersizing risks overloading, reduced efficiency, or even equipment failure. Therefore, accurately calculating the economic capacity is essential for a safe, efficient, and cost-effective distribution system. Calculation Principle and Core Formula This calculator implements a widely accepted engineering model aligned with standards such as GB 50052 Code for Design of Power Supply and Distribution Systems: Core Formula: Se = (A × α) / (cosφ × T1) × √(K × T / 8760) Where: Se: Transformer economic capacity (kVA) A: Annual electricity consumption (kWh) α: Load development factor (typically 1.1–1.3) cosφ: Annual average power factor (usually 0.85–0.9) T1: Load operating time per year (h) K: Loss ratio (typically 1.05–1.2) T: Total power connection time per year (h), usually 8760 h Note: This formula accounts for load growth, power factor, operating hours, and transformer losses, making it suitable for practical engineering applications. How to Use This Calculator Enter annual energy consumption (kWh) — from utility bills or historical data Set load growth factor (default: 1.2; ≥1.2 recommended for new projects) Select load factor (e.g., 0.75 for industrial, 0.65 for commercial, 0.6 for residential) Input annual operating hours (e.g., 8760 for 24/7 operation) Click [Calculate] to instantly get the recommended economic transformer size (kVA) Real-World Examples Example 1: Industrial Park Power Design Annual consumption (A): 5,000,000 kWh Load development factor (α): 1.25 Average power factor (cosφ): 0.85 Annual load operating time (T₁): 7200 h Loss ratio (K): 1.10 Annual supply time (T): 8760 h Result: Se = (5,000,000 × 1.25) / (0.85 × 7200) × √(1.10 × 8760 / 8760) = 6,250,000 / 6120 × √1.10 ≈ 1021.24 × 1.0488 ≈ 1071 kVA → Recommended: 1250 kVA standard transformer Example 2: Commercial Complex Annual consumption (A): 1,200,000 kWh Load development factor (α): 1.15 Average power factor (cosφ): 0.85 Annual load operating time (T₁): 4000 h Loss ratio (K): 1.10 Annual supply time (T): 8760 h Result: Se = (1,200,000 × 1.15) / (0.85 × 4000) × √(1.10 × 8760 / 8760) = 1,380,000 / 3400 × √1.10 ≈ 405.88 × 1.0488 ≈ 426 kVA → Recommended: 500 kVA standard transformer Typical Applications Power planning for new factories or plants Retrofitting commercial building distribution systems Capacity assessment for data centers Transformer sizing for renewable energy projects (solar + storage) Substation design for residential communities Engineering consulting and feasibility studies Why Use Our Online Calculator? Free to use—no registration required Works on desktop, tablet, and mobile devices All calculations run locally—your data never leaves your device Results include standard size recommendations Built-in explanations for students, engineers, and designers Frequently Asked Questions (FAQ) Q: How do I determine the load factor? A: Load factor = Average Load / Peak Load. If unknown, typical values are: Industrial 0.7–0.85, Commercial 0.6–0.7, Residential 0.5–0.6. Q: Is annual operating time always 8760 hours? A: No. For non-24/7 facilities (e.g., malls open 10 hours/day), estimate actual high-load hours (e.g., 300 days × 10 h = 3000 h). Q: Does this work for dry-type and oil-immersed transformers? A: Yes. The method applies to all distribution transformers since economic sizing depends on load profile, not cooling type. References & Standards GB 50052-2009 Code for Design of Power Supply and Distribution Systems DL/T 572-2021 Operation Code for Power Transformers Industrial and Civil Power Distribution Design Manual (4th Edition)

This tool is designed for power equipment manufacturers, buyers, and engineers to quickly estimate the manufacturing cost of oil-immersed distribution transformers based on international standards and real-world production data. What Is Transformer Cost Estimation? Transformer cost consists of three main components: Material cost: Copper, aluminum, silicon steel, insulating oil, etc. Manufacturing cost: Winding, core assembly, testing, etc. Regional & market factors: Labor, logistics, tariffs, exchange rates This calculator estimates the theoretical manufacturing cost by inputting key parameters, helping with quoting, budgeting, and cost control. Calculation Principle and Core Formula The tool uses an industry-standard cost model that considers material usage and market prices: Total Cost = Copper Cost + Aluminum Cost + Iron Core Cost + Oil Cost + Process Factor Where: Copper Cost = Copper weight × Copper price Aluminum Cost = Aluminum weight × Aluminum price Iron Cost = Iron weight × Iron price Oil Cost = Oil volume × Oil price Process Factor = Total material cost × Price Factor Weights of copper, aluminum, iron, and oil are estimated from rated capacity, voltage, frequency, and winding materials using empirical formulas aligned with IEC 60076 standard designs. How to Use This Calculator? Select Standard: IEC 60076 or others (e.g., GB, IEEE) Select Country: Affects labor, tax, and logistics costs Enter Rated Capacity: in kVA (e.g., 25, 50, 100...) Set High-Voltage Winding: e.g., 30 kV Set Low-Voltage Winding: e.g., 1 kV Choose Frequency: 50 Hz or 60 Hz Select Winding Material: Copper (Cu) or Aluminum (Al) Input Current Market Prices: Copper price: $/t Aluminum price: $/t Iron price: $/t Oil price: $/t Set Price Factor: Default 1.0; adjust for regional differences (e.g., 1.2 for higher labor cost) Click [Calculate] to get the estimated cost Typical Applications Transformer manufacturer cost calculation and quotation International buyer price comparison and supplier evaluation Project investment budget preparation Cost comparison between copper and aluminum windings Cost sensitivity analysis across different countries Educational and training purposes Real-World Examples Example 1: 25 kVA Transformer Cost in Afghanistan Standard: IEC 60076 Country: Afghanistan Rated Capacity: 25 kVA H.V. Windings: 30 kV L.V. Windings: 1 kV Frequency: 50 Hz H.V. Winding Material: Cu L.V. Winding Material: Cu Copper Price: 11600 $/t Aluminum Price: 2920 $/t Iron Price: 448.6 $/t Oil Price: 1336 $/t Price Factor: 1.0 Estimated Result: Approximately $1,850 (including materials and process) Example 2: Cost Change When Using Aluminum Winding Change L.V. winding material to Al only All other parameters unchanged Estimated Result: Approximately $1,620 → Cost reduced by ~12.5% Note: Although aluminum has lower unit price, its lower conductivity requires larger cross-section, so savings are limited but beneficial for cost-sensitive projects. Why Choose Our Online Calculator? Works on desktop, mobile, and tablet Local calculation, no data upload Clear results with USD-based pricing Built-in explanations of cost structure Useful for comparing different configurations Frequently Asked Questions (FAQ) Q: Can this calculator give the actual factory price? A: Not exactly, but it provides a reference baseline. Real prices also depend on brand, certification, shipping, taxes, and profit margin. Q: How are copper and aluminum weights estimated? A: Based on empirical formulas derived from IEC 60076 standard designs, considering capacity, voltage, and frequency. Accuracy is typically ±10%. Q: Why does country affect the cost? A: Labor, energy, tax, and logistics costs vary significantly by region. The "Price Factor" reflects these differences. Q: Does it support other standards? A: Currently supports IEC 60076. Future versions will add GB, IEEE, and other standards. References & Standards IEC 60076-1: Power Transformers – Part 1: General GB 1094-2017: Chinese National Standard for Power Transformers "Transformer Design and Manufacturing" – China Machine Press