Most motors in control applications are just regular DC motors. A few are AC, and a few are true servomotors.
A true servo motor is optimized for high speed control systems. Specifically, you want fast linear response. To get this, they are typically somewhat high in cost, relatively low armature inertia, high torque (to give good acceleration). Often have marginal cooling (i.e. not rated for high duty cycle).
Electromagnetic induction is the production of a potential difference (voltage)
]across a conductor when it is exposed to a varying magnetic field.
Michael Faraday is generally credited with the discovery of induction in 1831
Faraday's law of induction is a basic law of electromagnetism predicting how a
magnetic field will interact with an
electric circuit to produce an electromotive force (EMF). It is the fundamental
operating principle of transformers,
inductors, and many types of electrical motors, generators and solenoids.
A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation.[1] The common, traditional solar cell used to generate electric solar power is a large area photodiode.
How a proximity sensor works :
A proximity sensor is a type of sensor which detects the presence of nearby objects called target without any physical contact. There are different types of proximity sensors such as inductive proximitysensor, capacitive proximity sensor, ultrasonic proximity sensor, photoelectric proximity sensor. Depending on the type of technology used proximity sensor emits an electromagnetic or electrostatic field, or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal when target comes closer to the face of sensor.
There are different kinds of proximity sensors. They are
Capacitive proximity sensor
Inductive proximity sensor
Photoelectric proximity sensor
Ultrasonic proximity sensor
The advantages of the non contact proximity sensors are:
No physical contact required with the target to be detected, therefore, no moving parts so no friction and wear out.
Fast switching characteristics
Unlimited number of switching cycles since there is no mechanical contact
Can work in harsh conditions
Any type of target material can be detected.
A proximity sensor is used in many applications such as in mobile phones and for level sensing. In Iphone proximity sensor is used to deactivate the touch screen when the phone comes near to the face.
Resistance Temperature Detectors (RTD)
as the name implies, are sensors used to measure temperature by correlating the resistance of the RTD element with temperature.
RTDs are relatively immune to electrical noise and therefore well suited for temperature measurement in industrial environments, especially around motors, generators and other high voltage equipment.
Type
Pt 100, 200, 500, 1000,
copper 50,53. etc
Element size (MI)
Wire wound ceramic encapsulated
Wire wound Glass encapsulated
Thin film ceramic encapsulated
Connection
2, 3, 4 wire
Accuracy
Class A, B 1/2, 1/3, 1/5, 1/10 DIN
When a battery is connected to a series resistor and capacitor, the initial current is high as the battery transports charge from one plate of the capacitor to the other. The charging current asymptotically approaches zero as the capacitor becomes charged up to the battery voltage. Charging the capacitor stores energy in the electric field between the capacitor plates.
Shockley diodes are curious devices, but rather limited in application. Their usefulness may be expanded, however, by equipping them with another means of latching. In doing so, each becomes true amplifying devices (if only in an on/off mode), and we refer to these as silicon-controlled rectifiers, or SCRs.
The progression from Shockley diode to SCR is achieved with one small addition, actually nothing more than a third wire connection to the existing PNPN structure
