Search results
Results from the WOW.Com Content Network
In transmission line and generator protection, by the mid-1990s the digital relay had nearly replaced the solid state and electro-mechanical relay in new construction. In distribution applications, the replacement by the digital relay proceeded a bit more slowly.
Strictly speaking, a manually operated switch is an electromechanical component due to the mechanical movement causing an electrical output. Though this is true, the term is usually understood to refer to devices which involve an electrical signal to create mechanical movement, or vice versa mechanical movement to create an electric signal.
Expected mechanical loads due to acceleration — some relays used in aerospace applications are designed to function in shock loads of 50 g, or more. Size — smaller relays often resist mechanical vibration and shock better than larger relays, because of the lower inertia of the moving parts and the higher natural frequencies of smaller parts ...
The switches then operate different elements of the controlled system - for example motors, valves, etc. A programmer may change or rearrange (reprogram) peg or cam positions. Much like the pegs in a music box cylinder activate the notes, in a drum sequencer, as the drum of the sequencer spins, the pegs run across switches activating machine ...
The first switch made using silicon micro-machining techniques was fabricated in 1978. [6] Those switches were made using bulk micromachining processes and electroplating . [ 7 ] In the 1980s, surface micromachining techniques were developed [ 8 ] and the technology was applied to the fabrication of switches, allowing for smaller, more ...
Switches can be designed to respond to any type of mechanical stimulus: for example, vibration (the trembler switch), tilt, air pressure, fluid level (a float switch), the turning of a key , linear or rotary movement (a limit switch or microswitch), or presence of a magnetic field (the reed switch). Many switches are operated automatically by ...
The control system is responsible for giving the required sequential pulses to the power circuitry. It is possible to do this using electro-mechanical means such as commutators or analog or digital timing circuits. Many controllers incorporate programmable logic controllers (PLCs) rather than electromechanical components. A microcontroller can ...
The generations of telephone switches before the advent of electronic switching in the 1950s used purely electro-mechanical relay systems and analog voice paths. These early machines typically utilized the step-by-step technique.