【School】】 relay weak fundamentals and applications..

<br> one time relay time relay is based on the electrical or mechanical input signal is given, at the scheduled time off after the output of electrical or electrical turn signal relay.. Common relay functions: A:-delay (On-delay .Operation) F: off delay (Off-delay Operation) Y: delta delay (Star / Delta Operation) C: with instantaneous output .- delay (With inst. Contact On-delay Operation) G: interval delay (Interval-delay Operation) .R: reciprocating delay (On-off repetitive delay Operation) K: Signal off delay (Off-signal delay Operation.) 1, time relay control power supply terminals generally can withstand the external surge voltage 1500V, if the surge voltage exceeds this value, .the surge absorbing devices shall be used to prevent the breakdown time relay burned; When the time following the. Electric duplication of work, this time the power off to the next power-on time (ending time) must be greater than the reset time, .otherwise the relay does not completely reset the next time it'll delay the work shift. instantaneous or non-action; off delay time relay of the power-on time must be greater than 0.5 seconds in order to have sufficient energy reserves to ensure that .the power is off by default time on or after the breaking load; time following the. electrical power supply circuit is high impedance under normal circumstances, therefore, cut off the power should be as small as possible the leakage current (semiconductor or RC, and .then the relay contacts to switch time), in order to avoid induced voltage caused by the fake off. malfunction (for off time delay, it will result to the delay time after power off but the relay does not release phenomenon).. Under normal .circumstances the residual voltage power terminals should be less than 20% of the rated voltage of power in terms of time delay should be less than 7% of rated voltage; time relay control the completion of its work, as far as possible to avoid further power ... Continuous power to make the products when the heat, thus speeding up the aging of electronic components, greatly reducing the service life.. 2, the load relay output contact connection time due to product size limitations, often the load capacity is not strong ., and therefore the protection of contacts can be absorbed in contact at both ends and connected devices (such as: RC, diodes, Qi. Zener diode, etc.).. Do not use the time to relay to directly control high capacity loads, .some of the load looks small, but because of the load current characteristics of the phenomenon of the emergence of Shaorong contacts, the table is the load form and the relationship between the inrush current.. <BLOCKQUOTE Dir = ltr style = "MARGIN .-RIGHT: 0px "> resistive load the load the standard form of surge current magnet load rated current standard of 10 to 20 times the rated load current of 5 to 10 times the motor rated current standard incandescent lamp load 10 .15 times rated current .mercury standards 1 to 3 times the standard load rated current of sodium gas lamp load 1 to 3 times the standard capacitive load rated current of 20 to 40 times the standard inductive load rated current 5 to 15 times the standard rated current </ BLOCKQUOTE> .3,. delay error <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> mainly repeat the error, set error, the temperature error and the voltage error, the table below.. Measurement error formula setting the conditions .surrounding the supply voltage temperature Ts repeated error ± 1 / 2 × (Tmax-Tmin) ÷ TMs × 100% maximum level at 20 ± 2 ° C rated voltage error (TMx-TM) ÷ TMs × 100.% supply voltage range of permissible .temperature error (TMx-TM) ÷ TMs × 100% rating -10 ~ +50 ° C setting error (TM-Ts) ÷ TMs × 100% 1 maximum scale value of 1 / 3 of 20. ± 2 ° CTM: the average .delay time measurements <BR> Ts: Setting <BR> TMs: maximum scale value <BR> TMx: at different voltages, temperatures measured by the average delay value <BR .> Tmax: The maximum measured <BR> .; Tmin: minimum measured </ BLOCKQUOTE> Second, how to choose the relay <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> in communications equipment, automatic devices,. household appliances, automobile electronics devices all .need to place the circuit transfer function, can use the relay.. As a wide application field, the requirements of different users vary the relay.. To meet the various requirements of different application areas, the relay manufacturers developed a number of different models and .different specifications, different performance of the relay; With the development of science and technology, the new structure, high performance, highly reliable relay. continue to emerge.. The face of many different specifications of relays, how to choose the proper use, will .directly affect machine performance and reliability.. How to reasonably choose the relay?. First in-depth analysis of the use of machine conditions, technical requirements, in accordance with the "value engineering" principle, put forward a reasonable selection relay products must .meet the technical performance.. Our technical staff, sales staff should be involved in the relay selection, play to our strengths, good staff, good sales service.. The following points can be, one by one to carry out analysis, research: appearance .and installation, the installation size; input parameters; output parameter; environmental conditions; safety requirements; reliability requirements.. The following were described according to the above requirements.. 1, appearance, installation, the installation size of the shape of the relay, .installation, the installation size of many varieties, the user must press the machine's specific requirements, make specific mounting area, allowing the height of the relay, installation, the installation size.. This is to select the relay first issues to consider.. The .following questions should be used Note: <OL> leads to the foot plate for the PC; foot spacing mostly 2.54 × n (n = 1,2,3 ... ..., following the same), such as JZW5; .also 2.5n, such as. JZG2-2 / B; also do not meet the standards of distance relays, such as MR72.. Generally leads to 3.5 feet in length.. Leads to the foot weldability, resistance to soldering heat relay, leads .to the base of the foot is not perpendicular to the relative degree should be strict requirements.. Quick connect relay; quick connect leads to the foot are usually 250 # (6.35 × 0.8), 187 # (4.75 × 0.5) 2 species.. .Leads to the foot pay special attention to this type of power plug requirements, 250 # leads to the foot: pulling torque> 10kg.cm; 187 # leads to the foot: pulling torque> 5kg.cm.. </ OL> Second ., the input parameters of different types of input parameters, is an important basis for selecting relay model.. Common types of input parameters are: AC input parameters.. When the input parameters for AC voltage (current) should be selected AC relay.. .Use this type of relay, should note the following issues: exchange rate ---- AC relay input voltage (current) is generally the frequency of 50HZ, or 60HZ.. Since the coil inductance between the two different pickup voltage is significantly different. .. The contract should be specified.. Temperature ---- AC relay because of eddy current loss, hysteresis loss, high temperature relay, usually 70 ° C to 80 ° C.. Operating temperature should not be too high, preferably 40 ° C .to 65 ° C, the formula to determine the ambient temperature: t1 ≤ t2-t3-150C; Note: t1: relay maximum ambient temperature, 0C; t2: enameled wire, insulation. long-term maximum allowable working temperature of materials 0C ( .B level for the 1300C; F level for the 1550C) t3: relay average temperature, 0C.. <BLOCKQUOTE Dir=ltr style="MARGIN-RIGHT: 0px"> Thus, when the increased ambient temperature, requiring temperature magnet .wire and insulation materials, a corresponding increase in level, the relay will significantly increase the cost.. Noise ---- AC relay work, will be issued exchange noise.. The initial requirement is less than 45dB (decibels), the actual use ., such as dirt, sand and dust has emerged magnetic, mechanical parameters change, the exchange will be increased noise.. Pickup voltage ---- AC relay pickup voltage is generally less than 80% VH (rated voltage less the same); allow .maximum pickup voltage of <90% VH.. Direct incentive to use the relay supply voltage when the supply voltage fluctuation is greater than ± 10%, will result in the failure of the relay, voltage too low, the pickup is not reliable, .there will be non-smoking and smoking seems to fail; voltage too high., temperature rise, damage to insulation failure of the relay.. When the supply voltage is greater than ± 10% (such as rural power grid voltage fluctuation).. .The contract should be made, as appropriate, will lower the voltage pickup; choose a higher level of enameled wire temperature, insulation materials.. </ BLOCKQUOTE> <UL dir=ltr> DC input parameters.. Such relay is widely used ., several cases points to be discussed.. Select DC relay, highlighting the sensitivity of the problem is L (coil rated power) problem, L and the output power of size, form, environmental conditions (temperature, vibration, shock .... ...) on to determine the sensitivity of the relay should be very careful not to. one-sided emphasis on sensitivity, the expense of other properties.. When the sensitivity is not critical, the general sensitivity of the DC relay can be used; .when sensitivity is higher, and high output power of electricity, harsh environmental conditions, available solid state relays, medium sensitivity of the relay; When asked high sensitivity (such as .0.2 W or less), can be mixed relay, polarized relay.. .However, higher prices mixed relay, larger; polarized relay poor adaptability to environment, load capacity is not high.. Longer duration when the input voltage, such as a few hours, days, months, and latching relay is recommended.. There are several .advantages: saving the input power; reduce the temperature rise relay; improve environmental adaptability.. But requires input for the pulse polarity requirements, input line complex.. Such as magnetic meter relays, satellite power control relays, relay contacts in a conduction state can .work dozens of hours, months, and latching is very cost-effective use.. Strict control of the power consumption occasions, often using latching relays.. When the input parameters and the frequency of 10Hz or more, requiring fast action relay, should be .used in reed relay, polarized relay or solid state relays.. Reed relay frequency up to 50 times / second, low prices, but the contact load capacity is low, generally only up to 50mA, 28VDC; polarized relay, solid state relays, switching .speeds of up to 100 times / second, work. reliable, but the price is high, the volume is relatively large; temperature change: the relay coil resistance changes with temperature changes, the relay action, the release of the voltage effect is obvious. .. Temperature rises to the limit temperature, the release voltage tends to the maximum dynamic voltage corresponding increase in absorption; the temperature dropped to extreme low temperatures, the release voltage tends to minimum pickup voltage will be reduced.. Extreme high temperatures do not pickup or .pull unreliable; very low temperatures do not release or slow release, will result in the failure of the relay.. On the current relay, ampere-turns for pickup, the release of ampere-turns from the coil resistance changes, so does not vary .with changes of temperature relay.. Must be noted that some users use the current relay, rather than as a constant current excitation relay, in fact, using a voltage source.. In this case, we must consider the impact of temperature on the coil .resistance.. Solid device switching incentive: a. solid device switching load capacity must be motivated to adapt to the relay coil, and allow sufficient margin (usually 2 times).. b. solid device switch is turned excitation circuit relay coil voltage distribution to .ensure that the actual excitation voltage on the line with rated voltage requirements.. c. solid switch off the device, the excitation circuit of the leakage current must be less than the minimum release of the relay current.. d. Solid reverse voltage switching device .must be 50 ~ 80V peak voltage compatible, and has the necessary margin.. Since the relay coil power moment, will have a high surge voltage, sometimes up to 1500V, the voltage peak is limited to within 50 ~ 80V, an appropriate suppression measures ... Low motivation and high-voltage output isolation: Modern industrial automation systems, often to low-voltage switch control circuit of small solid intermediate relay device input, and then convert the relay contacts 220VAC or 380VAC inductive load circuit (such as solenoids,. .contactor coil ... ...), automatic control and protection functions.. Relay actually assumed the low-voltage, high isolation and convert inductive load function.. Use of such intermediate relay, must have a good level of insulation resistance and long .-term tolerance of high-power, low temperature, humidity, dust and harmful gases role in the ability.. In general, anti-poor environmental capacity, sealed by means of measures to ensure the necessary protection; the level of insulation can be insulated .against electrical clearance from the strict control of distribution, identification can be guaranteed.. Interference, malfunction: high-density printed circuit board assembly of a variety of relays, in particular, solenoid or contactor with a large product, may produce electromagnetic mutual inductance, .resulting in the relay malfunction; also be part of their activities. shock, vibration, and lead to other relay malfunction.. For the sensitive type, easy to install Universal Relay products, related to the placement, to pay special attention.. Wired remote .incentives: automatic telephone ringing circuit, doorbell-type wiring incentives Dengjun category.. The incentive to use the connecting wire is longer, connecting wires should be considered the voltage drop on the actual value of incentives to ensure that the relay coil increases the actual incentive .value of the rated voltage to the required value of the request.. 3, the output parameter <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> load capacity of most of the domestic relay, marked only the largest .purely resistive load, which relays to the user in the choice of load, resulting in two kinds of misunderstanding,. lead to selection errors.. One misconception is: the user is often not practical pure resistance load, but the emotional, lights, motors .or capacitive loads, the load size equal to or close to the resistive load; misunderstanding of the Second: from the low-power load. level to the rated load, can adapt.. It should be noted, can be reliably converted 10A resistive load .relay, 10A inductive load can not be converted, not necessarily a reliable converted 10mA load.. Because different types of electrical contacts under load failure mechanism is different.. Should be emphasized that the relay contact failure is the main reason for failure.. Proper .understanding of contacts in different load types and different load conditions, the size of the electrical contact properties, failure phenomenon and failure mechanism, unified manufacturing side and the user's understanding of the work to improve the reliability of the relay, is particularly important.. Manufacturers .should improve the identification of the load contacts, content, for different load types should be separately marked.. </ BLOCKQUOTE> <OL> ---- the incandescent tungsten filament incandescent lamp cold resistance is very small, transient current surges connected .up to 15 times steady state current.. Such a large surge current will quickly contact erosion, welding output and even failure.. Generally limiting resistor in series to reduce inrush current.. ---- Motor stationary motor load input impedance is very small ., a large inrush current moment of starting.. Current injection, the current and magnetic field interaction torque.. When the motor is started, an internal force, resulting in contact current tends to decrease, turn-off, the contact occurs between the back .EMF, and often will cause arcing, causing contact erosion.. However, the motor is slow to stop, the motor's electromagnetic energy storage, kinetic energy into heat energy consumed part of the EMF will not be too high.. ---- Inductive .load inductor, solenoid, contactor coil, yoke rings are all inductive load current.. Instantly connected to the electromagnetic coil to inhibit the function of current rise, does not appear inrush current; but shut down, stored in the electromagnetic coil of electromagnetic arc through .the contacts between the consumed, which will lead to contact erosion,. metal transfer, James knot.. Using RC networks, diodes, varistors contact contact protection devices can reduce the ablation.. ---- Capacitive circuit capacitive load charging current may be .quite large, at the beginning, similar to short-circuit the capacitor, the current is only limited by the line resistance.. Sometimes, the user is not aware of its load is capacitive, in fact, a long transmission line, to eliminate the .magnetic interference filters, power supplies are strongly capacitive.. Limiting resistor in series, connected instantly to reduce inrush current.. DC load ---- AC load DC load difficult to break than as zero voltage, however, the contact breaking moment, that .arc, and continue to maintain the applied voltage, only the arc is stretched and can not self-sustaining and off.. Arc energy causes severe burning of contacts.. DC load relay contact gap should be designed larger.. Measures are often used arc .---- low generally refers to low open circuit voltage 10 ~ 100mV; contact microampere level to convert current 10mA.. Contact surface due to adsorption of organic matter in the compound, it is difficult to eliminate the conversion load, resulting in large and .unstable contact resistance, contact pressure drop increase.. Effective solution is: select the softening of low-voltage contact materials; the surface of the gold-plated 1 to 3u.. Guarantee from the contact surface clean process; control relays internal harmful gases. .. But the relay costs have increased significantly.. </ OL> 4, environmental conditions, ambient temperature <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> relay failure mode has led to the following aspects: .1. Temperature, high temperatures, the insulating material softening, melting; low. conditions, the material cracking.. Decrease the electrical properties of insulation resistance, resulting in failure.. High and low temperature alternation, the resulting structure, loose, moving parts .location changes, leading to pull the release out of control, poor contact or no contact with contacts.. Low temperatures, water vapor condensation within the relay, ice, resulting in electrical insulation.. High temperature conditions, the coil resistance increases, pickup voltage .corresponding increase, resulting in non-smoking non-smoking activities or may suck, cause the relay to fail.. High temperature conditions, the contact switch power load, the lower the ability of breaking arc, contact corrosion, metal transfer intensified, increasing the .possibility of failure, shortened life expectancy.. Temperature changes will lead to thermal relays, solid-state relay, mixed relay performance parameter instability.. Relay temperature range from product design, the choice of material properties and manufacturing process decisions, should be provided in .the product specifications within the selection.. Relay temperature, especially AC relay maximum ambient temperature plus the temperature rise should be less than the selected temperature level of magnet wire insulation material.. Relay selection, great attention must be the problem.. Temperature rating as .follows, recommended use: Extreme temperature (° C): -5 ± 3; -10 ± 3; -25 ± 3; -40 ± 3; -55 ± 3; -65 ± 3.. Limit high-temperature (° C .): 40 ± 2; 55 ± 2; 70 ± 2; 85 ± 2; 100 ± 2; 125 ± 2; 155 ± 2; 175 ± 2; 200 ± 2.. 2.. Humid heat of a threat to the relay .performance, specific performance is as follows: Long-term heat resistance to electricity will lead directly to decreased levels of insulation, resulting in complete failure.. Particularly long-term storage or use of exposed insulation by sand and dust and other pollution in the relay .and then by the heat effect, will result in insulation failure.. Non-sealed relays in hot and humid conditions, the coil due to electrochemical corrosion or mildew and broken, contact electrochemical corrosion, oxidation increase; metal parts corrosion rate increased significantly, the .relay performance deterioration, deterioration of operational reliability, which. complete failure.. In hot and humid conditions, the contact electric switch load, arc phenomenon intensified, resulting in reduced electrical life.. In tropical and subtropical use of electronic products, product design, .material selection must take full account of heat issues.. Low pressure conditions, the relay will produce the following adverse effects: insulation parts and components of the insulation resistance, dielectric withstand voltage drop, reduced ability to contact breaking arc, lower life expectancy.. .Deterioration of the relay heat, temperature increased.. On the power consumption of the relay is especially obvious.. For civil relay, no significant effect of low air pressure, do not go into the details.. Sand and dust pollution caused the failure of .the relay, the user has not yet attracted enough attention.. Conditions in the natural environment or the general environmental condition of industrial plant, in particular, electronic devices used on vehicles, sand and dust through the vents tend to crack into position within the relay .by over time, the boot look, can be found in dust and dirt accumulation, leading to. moving parts rotate (slip) not working, stuck; contacts electrical contact failure; in the wet under the effect of increasing the corrosion of metal parts, .pieces of insulation electrical insulation, resulting in failure.. Some of the power protection relay, automotive relay factory inspection by one or two years running, the relay continued failure.. Design and use must take full account of sand and dust contamination.. Users .according to practical needs, make a specific request.. Chemical pollution of the atmosphere ---- organic vapor in the atmosphere, oxygen, sulfur dioxide, salt spray, etc., on the relay contacts, metal parts, coil, there is erosion .of insulation parts, leading to bad electrical contacts, resulting in failure;. lead to corrosion of the coil wire disconnected, insulation levels.. Chemical harmful gases are ubiquitous in nature, but on different occasions, harmful gas (steam) the type is different ... Adopt technological measures, can be reduced, relieved of erosion, but the cost will be increased significantly.. Such as the military sealed relays, by prolonged high-temperature vacuum baking, the cavity filled with high purity relay N2, using electron beam .(or laser) to seal welding, the leakage rate of up to 10-8pa.cm3 / s; touch. points of gold-plated 1 ~ 3u.. Civil relay by price restrictions, just add shell, plastic mitigation of harmful gases in .the atmosphere (vapor) in the erosion, use, according to relay the load size, pros and cons of the environment can be appropriate hole to open the process to improve the cooling capacity. to reduce the internal organic vapor, sulfur dioxide pollution on the .contact surface.. ---- Relay in strong mechanical vibrations around power equipment, in transit will be encountered in a certain frequency range, the vibration acceleration; random vibration on behalf of missiles, high-thrust jet and rocket engine vibration stress field. .. (1) the impact of vibration on the performance of the relay in the: a. mechanical structure vibration may cause loosening, fatigue, fracture failure; b. close contact due to vibration than the standard specified time (10us, 100us) the instant .disconnect. failure; open contacts due to vibration than the standard specified time (10us, 100us) the failure of the moment closure; c. causes relative motion between moving parts, noise, wear and other physical failure.. (2) vibration Rating: .Recommended frequency range selection: 10 ~ 55HZ; 10 ~ 100HZ; 10 ~ 150HZ; 10 ~ 500HZ; 10 ~ 2000HZ.. 10 ~ 5000HZ; 55 ~ 500HZ; 55 ~ 2000HZ; 55 ~ 5000HZ; 100 ~ 2000HZ.. Amplitude (double .amplitude), acceleration recommended use: the junction frequency (57HZ) the following selection of double amplitude (mm): 0.035; 0.075; 0.15; 0.35; 0.75; 1.0; 1.5; 2.0; 3.5.. Frequencies above the junction, the choice of .acceleration (m/s2): 4.9 (0.5g); 9.8 (1.0g); 19.6 (2.0g); 49.0 (5g); 98 (10g); 147 (15g); 196 (20g); .294 (30g) .; 490 (50g) ---- relay the impact of transportation, handling, use often will be the role of mechanical shock.. The impact of shocks on the relay performance in: 1) the impact, causing structural looseness, damage, fracture .and loss of working capacity.. 2) The impact of close contacts to greater than the specified requirements (10us or 100us) Disconnect the failure of the moment; open contacts greater than the requirements generated (10us or 100us) moment closure and failure.. .For 1) to require the relay should have the impact strength of the performance, before and after the test measurement results of the provisions of the project shall comply with product standards.. For 2) the stability of the relay should have a performance impact, .to contact the contact state of the dynamic monitoring.. Graded impact acceleration (m/s2): 147 (11ms), 294 (18ms), 490 (11ms), 490 (3ms), 980 (11ms), 980 (6ms), .1960 (6ms), 1960 (3ms).. Acceleration relay ---- examination stress under constant acceleration can work ability.. In the conventional ground relays on the application of electronic devices, generally do not assessing the impact of constant acceleration.. .Not elaborate here, we can know about this.. In aviation, aerospace relays used in electronic devices, the impact of constant acceleration can not be ignored.. </ BLOCKQUOTE> 5, safety requirements <BLOCKQUOTE dir = ltr style = " .; MARGIN-RIGHT: 0px "> relay in the design, selection, safety requirements and should be full attention, especially in high power relay.. The main focus of the following assessment: <OL> ---- requires a flame .retardant insulation material properties; temperature ≥ grade temperature limit the maximum ambient temperature + winding temperature rise of +15 ° C.. Contact load capacity over 100 times ---- contact should be able to successfully (AC to 200) to switch twice the .rated load current.. The level of insulation against electrical conductivity between the parts of the relay ---- absolute must generally be resistance:> 100MΩ;> 500MΩ;> 10000MΩ.. Relay insulation between the conductive parts should be able .to withstand the highest possible use value of the voltage without damage, leakage current shall not exceed 100uA (or 1mA); also allowed arcing, flashover, or breakdown caused by damage to the ... Especially between coil and contact pressure, creepage distance should .pay particular attention.. When using the relay contact switch 220v or 380v inductive load, the voltage between coil and contacts often require higher than 4000Vac.. </ OL> </ BLOCKQUOTE> 6, the failure rate requirements of some applications, .the reliability of the relay demanding work, such as satellites, rockets, missiles, aircraft and use of program-controlled relay switch, Failure rate requirements of. L-level (1 × 10-6), Q-level (1 × 10 - .7); failure index now described as follows: corresponding to US military standard Failure rate Failure rate Failure rate symbols name the maximum allowable failure rate λmax 1 / 10. Class times LMPYW WLQ Ⅴ Ⅵ Ⅶ grade level 3 × 10-5 1 × 10 .-5 1 × 10-6 1 × 10-7 beneath the relay efficiency requirements, the cost will be increased significantly.. Raised the failure rate of the user requirements, to be very careful.. </ BLOCKQUOTE> Third, the relay .applications <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> category name dimensions defined by micro-relay longest side not larger than <, / SPAN> 10mm relay. Ultra-small size is greater than the longest .side relay 10mm, but not more than 25mm of the longest side of the relay mini relay size larger than 25mm, but not more than 50mm of the relay contact load according to the definition of micro-power relay category names. less than 0.2A low .power relay relay relay 0.2 ~ 2A 2 ~ 10A power relays in the relay power relay 10A relay above category names defined by use of communication relays (including the high-frequency relay). kind of relay contacts range from low to medium load current, less .demanding environmental conditions of use.. Industrial control relays used in industrial control relays, contacts load power, long life.. Household appliances used by the relay the relay, the safety performance requirements used in automotive relay automotive relay, relay switch such a large load .power, impact, vibration and high relays use a very wide area, and its. environmental conditions, technical requirements vary greatly.. Is the same with the use of the different areas of occasions, requirements vary.. The following can only seize the key ., a few examples, a brief description.. The key is to be described in the section after the application of knowledge, for the specific requirements of users, a reasonable choice.. 1, automotive automotive industry is increasingly widespread use of relays.. .The more common of the relay are: start the motor starter relay, loudspeaker relay, motor or generator circuit relays, charging voltage and current regulator relay, change signal flasher relay, light control, and air conditioning control relay following the. electrical appliances, automatic .sliding doors opening and closing control relay; window lift control relay.. Now the car's power multi-purpose 12V, mostly designed for coil voltage 12V.. Because it is battery powered, voltage instability; to harsh environmental conditions, pickup voltage V ≤ 60.