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Summary of Contents for ASCT1F46E

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Page 2: ...er to a summary of the consideration points regarding selection of relay Items Consideration points regarding selection Coil a Rating b Pull in voltage current c Drop out voltage current d Maximum continuous impressed voltage current e Coil resistance f Temperature rise Select relay with consideration for power source ripple Give sufficient consideration to ambient temperature and for the coil tem...

Page 3: ... current tends to cause contact welding easily because its inrush current is larger than that of the regular lamp load The load current characteristics in actual circuit and actual use condition must be examined and sufficient margin of safety must be provided in selection of a relay 5 LED lamp load It is necessary to check the contact reliability because the load current of the LED load is very s...

Page 4: ... use condition 17 Low frequency of switching Note that if the contact has not been switched for a long time period organic film tends to be generated on the contact surface which may cause contact instability 18 Ambient temperature Verify in the actual use condition since electrical life may be affected by use at high temperatures 19 Connection of coil surge absorption circuit If resistor diode ze...

Page 5: ... power supply voltage Diode and zener diode circuit Circuit Features Others It is effective in the diode circuit when the release time is too long Devices Selection Use a zener diode with a zener voltage about the same as the power supply voltage In the actual circuit it is necessary to mount the protective device diode etc in the immediate vicinity of the load If it is mounted too far away the ef...

Page 6: ... 1 Hot start voltage Temperature rise value of coil is greatly affected by circuit board connected harness connected connector heat dissipation of system modules and heat source around relay Please verify whether it is operating properly or inoperative under actual vehicle and actual use conditions Coil resistance and the pick up voltage will increase when the relay is used in a higher temperature...

Page 7: ...ped in the coil If this voltage exceeds the breakdown voltage of the transistor the transistor will be degraded and this will lead to damage It is absolutely necessary to connect a diode in the circuit as a means of preventing damage from the counter emf In case of DC relay connection of Diode is effective As suitable ratings for this diode the average rectified current should be equivalent to the...

Page 8: ...is in the detection capability of Schmitt circuit and care must be taken in setting the values 3 When there is chattering in the input signal because of waveform oscillation an CR time constant circuit should be inserted in the stage before the Schmitt trigger circuit However the response speed drops 6 Coil impressed circuit 1 Relay drive by means of a transistor 5 Avoid Darlington circuit connect...

Page 9: ...ns regarding ON OFF control circuits when used for temperature control circuits or similar one Care must be taken because the electrical life suffers extreme shortening when the relay contacts close simultaneously with an AC single phase power source 1 When the relay is turned ON and OFF using a SCR the SCR serves as a half wave power source as it is and there are ample cases where the SCR is easi...

Page 10: ...ue to a small amount of film on a contact surface 1 Coil applied voltage Mechanical relays produce an operational noise at operate and release time Note that if the coil applied voltage is higher at operate time the noise becomes larger 9 Operate noise 2 Operate noise at installation It is necessary to test relays in actual installation condition because operate noise may become larger in the inst...

Page 11: ...ould be considered for applications in an adverse environment 3 Silicon Silicon based substances silicon rubber silicon oil silicon based coating material silicon caulking compound etc emit volatile silicon gas Note that when silicon is used near relay switching the contacts in the presence of its gas causes silicon to adhere to the contacts and may result in contact failure Therefore please use a...

Page 12: ...al heat at connector contact area depending on use temperature and applying heat Sufficient margin of safety must be provided in selection of a connector 13 Installation 1 Connector installation Please select the proper material of connector and surface treatment to avoid corrosion at the contact area of relay terminal and connector and increase of resistance at connecting area which may be caused...

Page 13: ...sion and shrinkage of copper clad laminates Because copper clad laminates have a longitudinal and lateral direction the manner of punching fabrication and layout must be observed with care Expansion and shrinkage in the longitudinal direction due to heat is 1 15 to 1 2 of that in the lateral and accordingly after the punching fabrication the distortion in the longitudinal direction will be 1 15 to...

Page 14: ...utomatic mounting is available depending on the type of relay Be sure that the relays don t rattle Interference may occur internally if the gripping force of the tab of the surface mounting machine is too great This could impair relay performance 2 Flux Application Adjust the position of the PC board so that flux does not overflow onto the top of it This must be observed especially for dust cover ...

Page 15: ...nts e g Trichlene chloroethene thinner benzyl alcohol gasoline may damage the relay case Cleaning with the boiling method is recommended Avoid ultrasonic cleaning on relays Use of ultrasonic cleaning may cause breaks in the coil or slight sticking of the contacts due to the ultrasonic energy Do not cut the terminals When terminals are cut breaking of coil wire and slight sticking of the contacts m...

Page 16: ...ence gained from our advanced relay technologies to produce high performance electromagnetic relays compatible with surface mount technologies such as IRS and VPS Insertion Mount Technology Surface Mount Technology Insertion Mounting Technology IMT Components terminals are inserted into terminal holes of PC board and are soldered to copper pads on the other side of the board flow soldering Surface...

Page 17: ...onents are soldered to the board 5 Other Technologies Other reflow soldering technologies include those of utilizing lasers hot air and pulse heaters 2 Cautions for installation 1 Paste Soldering Mounting pads on PC boards must be designed to absorb placement errors while taking account of solderability and insulation Refer to the suggested mounting pad layout in the application data for the requi...

Page 18: ...ldering iron wattage 30 to 60 W Soldering time Less than 3 sec 3 Others For other solder methods except for the above such as hot air heating hot plate heating laser heating pulse heating etc please check for mounting and soldering condition before use It is recommended that the soldered pad be immediately cooled to prevent thermal damage to the relay and its associated components While surface mo...

Page 19: ... material so that the allowable range for vibration and shock is not exceeded 17 Storage transportation 2 Storage If the relay is stored for extended periods of time including transportation period at high temperatures or high humidity levels or in atmospheres with organic gas or sulfide gas sulfide film or oxide film may be formed on surface of the contacts which may cause contact instability con...

Page 20: ...n is becoming a serious concern for the manufacturing industry In short reliability has three senses i e reliability of the product itself serviceability of the product and reliability of product design 3 Intrinsic Reliability and Reliability of Use Reliability is built into products This is referred to as intrinsic reliability which consists mainly of reliability in the narrow sense Product relia...

Page 21: ...nym of Mean Time To Failure It indicates the mean time period until a product becomes faulty MTTF normally applies to unrepairable products such as parts and materials The relay is one of such objective of MTTF 4 Failure Rate Failure rate includes mean failure rate and momentary failure rate Mean failure rate is defined as follows Mean failure rate Total failure count total operating hours In gene...

Page 22: ...cidental failure period The initial failure period is followed by a long period with low stable failure rate In this period called accidental failure period failures occurs at random along the time axis While zero accidental failure rate is desirable this is actually not practical in the real world III Wear out failure period In the final stage of the product s service lifetime comes the wear out ...

Page 23: ...ability chart is a simpler alternative of complex calculation formulas The chart provides the following advantages 1 The Weibull distribution has the closest proximity to the actual failure rate distribution 2 The Weibull probability chart is easy to use 3 Different types of failures can be identified on the chart The following describes the correlation with the bathtub curve The value of the para...

Page 24: ...Is there stray capacitance between lead wires p3 4 21 Have precautions been checked for using of contact protective circuit p4 4 22 Is there a risk of dead short in the power supply p5 4 23 Is there a risk of short circuit in the power supply at load rejection p5 4 23 Is there a risk of insulation and breakdown voltage between contacts in each pole when high voltage is applied to a twin relay p5 4...

Page 25: ... dewing of relay p9 7 2 p10 12 7 p 11 12 9 Isn t there a risk of water or oil adhesion p11 12 8 Mounting Doesn t vibration or shock cause poor connection between a relay and a connector p11 13 1 Have precautions been checked for operating of flux applying and automatic soldering p13 15 1 p15 15 2 Have precautions been checked for cleaning operation of print board p13 15 1 p15 15 2 Isn t glass shot...

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