Mechanical circuit diagram symbol

Photocoupler

This is a comprehensive list of electrical and electronic symbols commonly used in circuit diagrams. These symbols represent various components and devices, making it easier to understand the layout and function of an electrical or control system. For example: - PA stands for Ammeter, which measures current. - PV represents a Voltmeter, used to measure voltage. - PJ is an Active Energy Meter, while PJR is a Reactive Energy Meter. - PF is a Frequency Meter, and PPA is a Phase Meter. - PM is a Maximum Demand Meter (also known as a Load Monitor). - PPF indicates a Power Factor Meter, and PW is an Active Power Meter. - PR is a Reactive Power Meter, and PAR is a Reactive Current Meter. Other common symbols include HA (Acoustic Signal), HS (Optical Signal), and HL (Indicator Light). Lights are often categorized by color: HR (Red Light), HG (Green Light), HY (Yellow Light), HB (Blue Light), and HW (White Light). Connectors and wiring are also represented with specific symbols. XB is a Connecting Piece, XP is a Plug, and XS is a Socket. XT is a Terminal Board, while W represents Wire, Cable, or Busbar. For DC systems, WB is the DC Bus, and WIB is a Plug-in (Feed) Busbar. WP is a Power Branch Line, WL is a Lighting Branch Line, and WE is an Emergency Lighting Branch Line. Control and signal buses include WC (Control Small Bus), WS (Signal Small Bus), WF (Flash Small Bus), and WFS (Accident Sound Small Bus). Voltage and emergency lighting buses are denoted by WV and WELM respectively. Protective devices such as F (Arrester), FU (Fuse), and FTF (Fast Fuse) are essential in electrical systems. FV is a Voltage Limiting Protection Device, and C represents a Capacitor. Control switches like SBF (Forward Button), SBR (Reverse Button), and SBS (Stop Button) are used to manage operations. SBE (Emergency Button) and SBT (Test Button) are also standard. Sensors and transducers include BP (Pressure Transducer), BT (Temperature Converter), and BV (Speed Converter). Time-measuring sensors are labeled BT1 and BK. Heating devices, lighting, and air conditioning are represented by FH (Heating Device), EL (Lighting), and EV (Air Conditioner). Electric heaters are denoted by EE. Inductors, reactors, and resistors have their own symbols: L (Induction Coil), LF (Excitation Coil), LA (Arc Suppression Coil), LL (Filter Capacitor), and R (Resistor). Special components like thermistors (RT), photoresistors (RL), and varistors (RPS) are also included in this list. Grounding and discharge resistors are marked as RG and RD respectively. This symbol list is widely used in industrial and commercial electrical engineering, helping engineers and technicians quickly interpret and design complex systems.