Published on August 3, 2014
Around the characteristics of electromagnetic relays: Around the characteristics of electromagnetic relays Working principle and characteristics of the older students talked for electromagnetic relays : Working principle and characteristics of the older students talked for electromagnetic relays Electromagnetic relays general by the electromagnet , the armature , spring , contacts and other components , the operation of the circuit by a low-pressure and high-pressure work circuit control circuit composed of two parts . Electromagnetic relays can also achieve remote control and automatic control. As long as the voltage across the coil with a coil in a constant current will flow , so that an electromagnetic effect , materials lifting equipment the armature will be attracted to overcome the electromagnetic force of the suction action of the return spring to pull the core , so as to drive the armature dynamic contact with the stationary contact ( normally open contact ) pull . When the coil power, the electromagnetic suction disappeared , the reaction force of the spring armature will return to the original position, so that the moving contact with the original stationary contacts ( normally closed contacts ) released. Thus pull , release, so as to achieve conduction in the circuit , the purpose of cutting . For the relay , " normally open, normally closed " contact , it can be distinguished : the relay coil is not energized in a disconnected state of stationary contacts , called "normally closed contact" ; in the ON state of said stationary contacts as " normally open contact ." Your actual operation crane hook opening measurements do leptospirosis : Your actual operation crane hook opening measurements do leptospirosis Leptospira opening measurement method is as follows : In accordance with the specified rated load hook plate load test performed , incrementally and gradually increase the load of 1.25 times the rated load , lifting time of less than 10min. After unloading , the value of the original opening size comparison with the opening of the caliper hook , increase the amount of its opening level should not exceed 0.25%. When you enable a new hook , 3 ton hoist crane leptospirosis can be used on both sides of the opening punch each punch a mark , measure the distance between the marks and record the original size of the opening . If leptospirosis than the original opening of the opening degree of deformation increased by 15% , should be replaced. Crane motor relay to a large inventory : Crane motor relay to a large inventory ( 1 ) Time relay function: From the relay control operation time in the circuit , a delay to open or close the contacts of the principle of automatic control of appliances using electromagnetic or mechanical action principle . Because of this relay has a delay effect only when the power release , also often referred to as off -delay timer relay , which extend the length of time can be adjusted according to need . Mural Jib Crane control panel in the use of JT3 series DC electromagnetic relay . JT3 series of DC by the time relay coil , moving core , core static , and static and dynamic fine-tuning of the spring contacts and other components. Its role is to delay the magnetic flux according to the principles of slow decay obtained , the delay is determined by the length of the flux rate of decay . The yoke of the relay ( static core ) on a copper or aluminum cap damping when the coil power, the induced current generated in the damping sleeve , the magnetic flux of the iron core current to decay slower , so breaking after power relay armature ( moving core ) can not be released immediately , but should be released after a certain time and then play a role in the delay . ( 2 ) time relay installation and maintenance : ① relay should be no damage, deformation and dirt phenomenon . ② running time relay should be no overheating or abnormal sound. ③ time relay setting values and action values should be equivalent to the contact action altogether , delay error should be less than 10%. ④ adjust the delay time relay generally the most simple way is to change the thickness of non-magnetic spacer , can also be used to change armature spring tension uniform approach to adjust the delay time . ⑤ move off the auxiliary relay contacts ( general access circuit ) at both ends of the resistor is approximately 0 . ⑥ energized when analog or manual simulation time relay, can correct action , delay accurate. ⑦ time relay should not be lower than the voltage at the rated voltage of occasions , the temperature change will also affect the stability of the delay .