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Relais
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Electromechanical relays are (were?) apparatus consisting of an electromagnet, as imput element, which, when energized, mecanically operates electric contact/s acting as output device/s. Depending on type, relay may have several contacts of different kind: normally open (NO) or normally closed (NC), swith break bebor make type (BBM) or make before break (MBB). Insulates input and outputs.
Kind regards Julian
Kind regards Julian
Hi,
I think "relais" is a derivation of the English "relays".
It is possibly French in origin and/or a spelling mistake in English text.
When I did a search on the word there were quite a few hits, all of which refered to relay action.
If you know about relays and just didn't know about the word you mentioned then just ignore the next bit.
If you are not sure what a relay is then :-
Electro Mechanical
An Electro Mechanical relay is a device that uses the fact that when a current flows through a coil it generates a magnetic field.
A relay has a coil usually with an iron core. As the input current flows through the coil it generates a magnetic field concentrated in that core.The magnetic field is used to pull an armature. The armature then switches the contacts. Like a switch the contacts can be Normally Open (NO) or Normally Closed (NC). When switched they change to thier opposite state. When the current stops flowing through the coil the magnetic field is lost and a spring pulls the armature/contacts back to their original position.
They are used for a numbe of reasons.
1. A small voltage can control high voltages (eg a 5v coil could switch 100's of volts providing the contacts were so rated)
2. a single voltage can switch on/off many other voltages
3. As a distant controlled switch
Solid State
A solid state relay is a device that uses semiconductors to perform the action of a relay (see above) The advantage of these is they have no moving parts and are note prone to wear or contact resistance. The disadvantage is the lack of electrical isolation (although some do have optically isolated inputs)
The above explanation is VERY brief, there are as many types of relays as words on this post which I have not even mentioned eg Reed relay, Time Delay relay, Thermal relay, Co-ax relay etc.
Any help ?, yes no let me know.
Regards
I think "relais" is a derivation of the English "relays".
It is possibly French in origin and/or a spelling mistake in English text.
When I did a search on the word there were quite a few hits, all of which refered to relay action.
If you know about relays and just didn't know about the word you mentioned then just ignore the next bit.
If you are not sure what a relay is then :-
Electro Mechanical
An Electro Mechanical relay is a device that uses the fact that when a current flows through a coil it generates a magnetic field.
A relay has a coil usually with an iron core. As the input current flows through the coil it generates a magnetic field concentrated in that core.The magnetic field is used to pull an armature. The armature then switches the contacts. Like a switch the contacts can be Normally Open (NO) or Normally Closed (NC). When switched they change to thier opposite state. When the current stops flowing through the coil the magnetic field is lost and a spring pulls the armature/contacts back to their original position.
They are used for a numbe of reasons.
1. A small voltage can control high voltages (eg a 5v coil could switch 100's of volts providing the contacts were so rated)
2. a single voltage can switch on/off many other voltages
3. As a distant controlled switch
Solid State
A solid state relay is a device that uses semiconductors to perform the action of a relay (see above) The advantage of these is they have no moving parts and are note prone to wear or contact resistance. The disadvantage is the lack of electrical isolation (although some do have optically isolated inputs)
The above explanation is VERY brief, there are as many types of relays as words on this post which I have not even mentioned eg Reed relay, Time Delay relay, Thermal relay, Co-ax relay etc.
Any help ?, yes no let me know.
Regards
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