Q: Is a relay an electrically operated switch? ¶
Q: Is a relay activated? ¶
A: Yes, the circuit is connected when the relay is inactive.
Q: Are relays often used in transceivers which combine transmitter and receiver in one unit? ¶
Q: Is a relay a reed switch enclosed in a solenoid? ¶
Q: Are relays constructed with a kind of "shock absorber" mechanism attached to the armature which prevents immediate? ¶
A: Yes, and full motion when the coil is either energized or de-energized.
Q: Is a relay a form of reed relay in which the contacts are wetted with mercury? ¶
Q: Are relays preferred? ¶
Q: Is a relay a relay that uses mercury as the switching element? ¶
Q: Is a relay de-energized there is an air gap in the magnetic circuit? ¶
Q: Are relays found in avionics and numerous industrial applications? ¶
Q: Are relays widely used on railways following British practice? ¶
Q: Are relays used wherever it is necessary to control a high power or high voltage circuit with a low power circuit? ¶
A: Yes, and especially when galvanic isolation is desirable.
Q: Are relays made with different main contact sets? ¶
A: Yes, and either NO, NC or changeover, and one or more auxiliary contact sets, often of reduced current or voltage rating, used for the monitoring system.
Q: Were relays the standard method of controlling industrial electronic systems? ¶
Q: Are relays equivalent to a pair of SPST switches or relays actuated by a single coil? ¶
Q: Are relays now rarely used? ¶
Q: Are relays used to switch low-voltage signals where the mercury reduces the contact resistance and associated voltage drop? ¶
A: Yes, for low-current signals where surface contamination may make for a poor contact, or for high-speed applications where the mercury eliminates contact bounce.
Q: Is a relay matched to the transmission line impedance of the system? ¶
A: Yes, for example, 50 ohms.
Q: Is a relay operating at its derated value? ¶
A: Yes, and it is controlling a smaller value of current than its maximum make and break ratings.
Q: Are relays used to detect overload and other faults on electrical lines by opening and closing circuit breakers? ¶
Q: Are relays position-sensitive and must be mounted vertically to work properly? ¶
Q: Are relays switches, the terminology applied to switches is also applied to relays? ¶
A: Yes, a relay switches one or more poles, each of whose contacts can be thrown by energizing the coil.
Q: Are relays in long telegraph lines? ¶
A: Yes, where the weak signal received at an intermediate station could control a contact, regenerating the signal for further transmission.
Q: Is a relay being switched? ¶
A: Yes, and the relay contacts retain this setting across a power outage.
Q: Were relays used for control of automated systems for machine tools and production lines? ¶
Q: Are relays large considering the mostly small voltages and currents that they switch? ¶
Q: Are relays devices which generally implement safety functions? ¶
Q: Are relays arranged for an intentional delay in operating their contacts? ¶
Q: Is a relay exposed to the same environment as the motor? ¶
A: Yes, and a useful though crude compensation for motor ambient temperature is provided.
Q: Is a relay a specialized kind of multi-way latching relay designed for early automatic telephone exchanges? ¶
Q: Were relays replaced by delay line memory? ¶
A: Yes, and which in turn was replaced by a series of ever-faster and ever-smaller memory technologies.
Q: Were relays used in middle 20th Century telephone exchanges to detect faint pulses and correct telegraphic distortion? ¶
Q: Are relays devices designed to work for wide voltage ranges such as 24 to 240 VAC/VDC and wide frequency ranges such as 0 to 300 Hz? ¶
Q: Is a relay a type standardized for industrial control of machine tools? ¶
A: Yes, and transfer machines, and other sequential control.
Q: Are relays useful in applications where interrupted power should not be able to transition the contacts? ¶
Q: Is a relay used as a TR relay? ¶
A: Yes, and which switches the antenna from the receiver to the transmitter.
Q: Is a relay driving a large? ¶
A: Yes, or especially a reactive load, there may be a similar problem of surge currents around the relay output contacts.
Q: Are relays much more resistant than semiconductors to nuclear radiation? ¶
A: Yes, and they are widely used in safety-critical logic, such as the control panels of radioactive waste-handling machinery.
Q: Is a relay a safety device sensing the accumulation of gas in large oil-filled transformers? ¶
A: Yes, and which will alarm on slow accumulation of gas or shut down the transformer if gas is produced rapidly in the transformer oil.
Q: Were relays used extensively in telephone exchanges and early computers to perform logical operations? ¶
Q: Is a relay activated? ¶
A: Yes, the circuit is disconnected when the relay is inactive.
Q: Were relays used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit? ¶
Q: Is a relay a function of the material used to make the device? ¶
Q: Was a relay de-energized? ¶
A: Yes, and then the movement opens the contacts and breaks the connection, and vice versa if the contacts were open.
Q: Is a relay derated? ¶
Q: Are relays used as part of an engineered safety system? ¶
Q: Are relays manufactured to operate quickly? ¶
Q: Are relays used where it is necessary to control a circuit by a separate low-power signal? ¶
A: Yes, or where several circuits must be controlled by one signal.