The definition of relay: Relay is one kind is measured when the input (report, magnetism, sound, smooth, hot) when reaching fair value, sendout will produce the automata parts of an apparatus or appliance that bouncing type changes.

 

Relay is the device of a kind of control that our life middling uses, common sense comes up saying is switch, be shut below the condition that satisfies in the condition or open. The switch character of relay is in a lot of control systems receive wide application in the control system of disperse especially.

 

 

 

Measure when the input (wait like voltage, electric current, temperature) when achieving a regulation to be worth, make controlled output circuit guides the electric equipment that connect or disconnects. Can divide the tolerance that it is report (wait like electric current, voltage, frequency, power) relay and blame n (wait like temperature, pressure, speed) relay two kinds big. Have an action stability of fast, job, service life long, volume is minor wait for an advantage. Apply extensively at electric power protection, automation, motion, remote control, measure and in the device such as communication.

 

Relay is parts of an apparatus of control of a kind of electron, it has control system (call an input loop again) and controlled system (say to output loop again) , apply in automata circuit normally, it is the ” of recloser of a kind of “ that goes controlling bigger electric current with lesser electric current actually. Reason is having the effect such as self-adjusting, safe protection, change-over circuit in circuit.

 

 

1, the working principle of electromagnetism relay and character

 

Electromagnetism type relay is general wait for composition by reed of core, coil, armature, contact. Want the tension with in coil two end are added constant only, constant electric current can have flowed in coil, produce electromagnetism effect thereby, the pulling force that return spring overcomes below the action that armature can draw in electromagnetism force sucks Xiang Tiexin, drive armature thereby use contact and fixed contact (often open contact) suck close.

 

After coil cuts off the power, electromagnetic attraction also disappears subsequently, armature can return former position in the counterforce of bedspring, make use contact and original fixed contact (often close contact) suck close. Such suction close, release, achieved thereby guide mediumly in circuit, the purpose that cut off. Often leave to the “ of relay, often close ” contact, such OK coming that distinguish: Coil was not in relay when electrify disconnect the fixed contact of condition, call “ to often open contact ” ; Be in put through the fixed contact of condition calls “ to often shut contact ” .

 

2, the working principle of relay of heat quick dry spring and character

 

Relay of heat quick dry spring is a kind of new-style heat that uses heat quick magnetism to material detects and control temperature quick switch. It is installed by annulus of feeling lukewarm magnetism, constant magnetism annulus, canal striking spring, heat conduction piece, a few accessory comprise plastic underlay etc. Heat quick does reed relay need not coil excitation, and the action of switch of magnetic force drive that produces by constant magnetism annulus. Constant magnetism annulus whether providing magnetic force to canal striking spring is by annulus of feeling lukewarm magnetism lukewarm those who control characteristic decision.

 

3, solid state relay (SSR) working principle and character

 

Solid state relay is a kind two terminal are carried for the input, additional the 4 upright parts of an apparatus or appliance that two terminal carry for output, segregation is used among implementation of parts of an apparatus is input-output electric segregation.

 

Solid state relay can be divided by type of laden power source for communication model with straight flow pattern. Can divide by switch type to often leave model and often shut model. By segregation type can be divided to mix model, transformer segregation keep apart with photoelectricity model, keep apart with photoelectricity model for most.

 

 

1, rated job voltage

 

It is the voltage that place of the coil when showing relay works normally needs. Differ according to the model of relay, can be alternating voltage, also can be volts d.c. .

 

2, dc block

 

It is the dc resistor of the coil in pointing to relay, can measure through all-purpose watch.

 

3, suck add up to electric current

 

It is to show relay can arise suck those who join a movement the smallest electric current. When be used normally, given electric current must is more than slightly suck add up to electric current, such relay just work steadily. And the working tension that increases to coil place, do not exceed 1.5 times of rated job voltage commonly, can produce bigger electricity otherwise and coil burn down.

 

4, release current

 

It is to show relay produces those who release an action the biggest electric current. When relay sucks the electric current that closes position to reduce fixed rate, relay can restore not the release condition of electrify. At this moment electric current is less than far suck add up to electric current.

 

5, contact switch voltage and electric current

 

It is the voltage that shows relay allows to load and electric current. It decided relay can control the bulk of voltage and electric current, this value cannot exceed when using, damage very easily otherwise the contact of relay.

 

 

1, measure contact resistance

 

With the resistor archives of all-purpose watch, measure often shut contact and the resistor that move a point, its block value should is 0, (Can measure so that contact block value is in Europe of 100 fine long hair with more exact pattern less than) ; And often open contact and the block cost that move a point to be infinity. Can distinguish from this giving that is to often close contact, that is to often open contact.

 

2, line encircles resistor

 

Archives of R×10Ω of usable and all-purpose watch measures relay the block value of coil, judge this coil to whether existing thereby open circuit phenomenon.

 

3, measure suck close voltage and suck add up to electric current

 

Search adjustable regulated power supply and ammeter, input a group of voltage to relay, and ammeter is strung together to undertake monitoring in power supply loop. Increase power source tension slowly, hear relay to suck when combining sound, write down this to suck close voltage and suck add up to electric current. To beg accurate, can try many times and beg average.

 

4, measure release voloage and release current

 

Also be to resemble afore-mentioned join in that way test, suck when relay happening after closing, reduce power supply tension gradually again, should hear relay to happen again when releasing sound, record next right now voltage and electric current, yi Ke tries many times and obtain average release voloage and release current.

 

Usually, the release voloage of relay is sucking the 50 ％ of 10 ～ that combine tension about, if release voloage is too small (the suction that is less than 1/10 combines tension) , cannot use normally, such meetings cause menace to the stability of circuit, the job is fluky.

 

4, the electric symbol of relay and contact form

 

Relay coil grows pane symbol to express with in circuit, if relay has two coil, draw two paratactic long pane. The literal symbol “J” that be at the same time inside long pane or grows the relay on the mark other pane.

 

The contact of relay has two kinds to represent a means: One kind is draw them in long pane a side directly, this kind of notation is relatively intuitionistic. Another kind is according to circuit connective needs, draw each contact in respective control circuit respectively, tag respectively beside the contact of same relay and coil normally on same literal symbol, organize contact group on number, in order to show distinction.

 

The contact of relay has 3 kinds of basic forms:

 

1, move close model (H) coil is illogical the two contact when report disconnect, after electrify, two contact close. Express in order to add up to the “H” of phoneticize word head of the word.

 

2, break model (D) coil is illogical the two contact when report close, two contact after electrify disconnect. The “D” of phoneticize word head that uses a word expresses.

 

3, changeover (Z) this is contact group model. Group of this kind of contact shares 3 contact, namely among it is to use contact, each one fixed contact falls on. Coil is illogical when report, move contact and among them a fixed contact disconnects and another closes, after coil electrify, move contact to move, make disconnect so into close, close so into disconnect condition, achieve the goal of changeover. Such contact group calls changeover contact. Turn with “ the “z” of phoneticize word head of ” word expresses.

 

5, of relay choose

 

1, know essential condition first:

 

① controls the power source voltage of circuit, the biggest electricity that can provide;

 

② is controlled the voltage in circuit and electric current;

 

③ is accused the contact that circuit needs form of a few group, what. When choosing relay, the power source voltage that dominates circuit commonly can serve as chosen basis. Control circuit should provide enough working electricity to relay, otherwise relay is sucked closing is not stable.

 

2, after consulting to determine use condition about the data, can search relevant data, find out the model of the relay of need and norms date. If at hand already had relay, can check according to the data whether can use. Final consideration measure is appropriate.

 

3, the volume that notes appliance. If be used at using electric equipment commonly, outside dividing consideration box cubage, small-sized relay basically considers circuit board to install layout. To small-sized electric equipment, if device of toy, remote control should be chosen,exceed small-sized relay product.