Electrical Symbols — Switches and Relays

The vector stencils library "HVAC controls" contains 23 symbols of HVAC controls (sensors, actuators, timers, controllers, I/ O points).
"HVAC (... Heating, Ventilation and Air Conditioning) is a control system that applies regulation to a heating and/ or air conditioning system. ...
Central controllers and most terminal unit controllers are programmable, meaning the direct digital control program code may be customized for the intended use. The program features include time schedules, setpoints, controllers, logic, timers, trend logs, and alarms. The unit controllers typically have analog and digital inputs that allow measurement of the variable (temperature, humidity, or pressure) and analog and digital outputs for control of the transport medium (hot/ cold water and/ or steam). Digital inputs are typically (dry) contacts from a control device, and analog inputs are typically a voltage or current measurement from a variable (temperature, humidity, velocity, or pressure) sensing device. Digital outputs are typically relay contacts used to start and stop equipment, and analog outputs are typically voltage or current signals to control the movement of the medium (air/ water/ steam) control devices such as valves, dampers, and motors." [HVAC control system. Wikipedia]
Use the design elements library "HVAC controls" for drawing the HVAC system diagrams, controls drawings, and automated building control and environmental control system layuout floor plans using the ConceptDraw PRO diagramming and vector drawing software.
The shapes library "HVAC controls" is included in the HVAC Plans solution from the Building Plans area of ConceptDraw Solution Park.

The vector stencils library "HVAC controls" contains 23 symbols of HVAC controls (sensors, actuators, timers, controllers, I/ O points). Use it for drawing HVAC system diagrams, controls drawings, and automated building control and environmental control systems design. The example "HVAC controls - Vector stencils library" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the HVAC Plans solution from the Building Plans area of ConceptDraw Solution Park.

The vector stencils library "Fluid power valves" contains 93 symbols of pre-made hydraulic and pneumatic valves, including directional control valves, flow control valves, pressure control valves, and electrohydraulic and electropneumatic valves.
"Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.
The opening or closing of control valves is usually done automatically by electrical, hydraulic or pneumatic actuators. Positioners are used to control the opening or closing of the actuator based on electric, or pneumatic signals.
A control valve consists of three main parts in which each part exist in several types and designs: Valve's actuator, Valve's positioner, Valve's body.
" [Control valves. Wikipedia]
The shapes example "Design elements - Fluid power valves" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "Switches and relays" contains 58 symbols of electrical contacts, switches, relays, circuit breakers, selectors, connectors, disconnect devices, switching circuits, current regulators, and thermostats for electrical devices.
"In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another.
The most familiar form of switch is a manually operated electromechanical device with one or more sets of electrical contacts, which are connected to external circuits. Each set of contacts can be in one of two states: either "closed" meaning the contacts are touching and electricity can flow between them, or "open", meaning the contacts are separated and the switch is nonconducting. The mechanism actuating the transition between these two states (open or closed) can be either a "toggle" (flip switch for continuous "on" or "off") or "momentary" (push-for "on" or push-for "off") type.
A switch may be directly manipulated by a human as a control signal to a system, such as a computer keyboard button, or to control power flow in a circuit, such as a light switch. Automatically operated switches can be used to control the motions of machines, for example, to indicate that a garage door has reached its full open position or that a machine tool is in a position to accept another workpiece. Switches may be operated by process variables such as pressure, temperature, flow, current, voltage, and force, acting as sensors in a process and used to automatically control a system. ... A switch that is operated by another electrical circuit is called a relay. Large switches may be remotely operated by a motor drive mechanism. Some switches are used to isolate electric power from a system, providing a visible point of isolation that can be padlocked if necessary to prevent accidental operation of a machine during maintenance, or to prevent electric shock." [Switch. Wikipedia]
"A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.
A type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protective relays"." [Relay. Wikipedia]
The shapes example "Design elements - Switches and relays" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "Valve assembly" contains 141 symbols of pressure and flow regulators, flow direction indicators, controls, and symbols to design flow paths of control valves.
Use these valve assembly shapes to design the engineering drawings of hydraulic and pneumatic valve assemblies in fluid power systems.
"Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.
The opening or closing of control valves is usually done automatically by electrical, hydraulic or pneumatic actuators. Positioners are used to control the opening or closing of the actuator based on electric, or pneumatic signals.
A control valve consists of three main parts in which each part exist in several types and designs: Valve's actuator, Valve's positioner, Valve's body.
" [Control valves. Wikipedia]
The shapes example "" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "Lamps, acoustics, readouts" contains 35 element symbols of lamps, acoustic components, electrical measuring instruments for drawing electrical schematics and electronic circuit diagrams.
"Electrical measurements are the methods, devices and calculations used to measure electrical quantities. Measurement of electrical quantities may be done to measure electrical parameters of a system. Using transducers, physical properties such as temperature, pressure, flow, force, and many others can be converted into electrical signals, which can then be conveniently measured and recorded." [Electrical measurements. Wikipedia]
"A lamp is a replaceable component such as an incandescent light bulb, which is designed to produce light from electricity." [Lamp (electrical component). Wikipedia]
"An electric bell is a mechanical bell that... functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing or clanging sound." [Electric bell. Wikipedia]
"A buzzer or beeper is an audio signalling device, which may be mechanical, electromechanical, or piezoelectric." [Buzzer. Wikipedia]
"Electronic sirens incorporate circuits such as oscillators, modulators, and amplifiers to synthesize a selected siren tone (wail, yelp, pierce/ priority/ phaser, hi-lo, scan, airhorn, manual, and a few more) which is played through external speakers." [Siren (noisemaker). Wikipedia]
"A microphone (colloquially called a mic or mike...) is an acoustic-to-electric transducer or sensor that converts sound in air into an electrical signal. ...
Most microphones today use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone) or piezoelectric generation to produce an electrical signal from air pressure variations." [Microphone. Wikipedia]
The symbols example "Design elements - Lamps, acoustics, readouts" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.