SU758296A1 - Key change-over switch - Google Patents

Description

(54). KEY SWITCH '

The invention relates to electrical engineering and can be used in electric and radio equipment, where it is necessary to block from simultaneously turning on two keys.

A well-known key switch comprising a button, a reset mechanism made in the form of a two shoulders lever and an electromagnetic mechanism in which one lever is connected with one shoulder to a bar having the ability to move along ball guides, wherein the central ball is preloaded by a spring, which is a movable ι a tact plate of the electromagnetic mechanism, and a fixed contact plate is a metal substrate having a ceramic jumper [1].

However, this switch has a relatively low reliability and complex kinematic design.

A key switch with automatic reset is also known, which contains keys equipped with pushers resting on the armature of electromagnetic relays with windings, normally open and normally closed relay contacts, the beginnings and ends of the relay current coil2 are connected to normally open contacts of free relay contact groups, and normally closed contacts - with the movable contacts of the contact groups of the relay of adjacent keys with the power supply through the movable contacts of the relay of the extreme keys of the switch [2].

The disadvantage of this device is that when you press, for example, two (or more) keys, the controlled relay circuits are switched • because their anchors are pressed, and this state persists until the keys are pressed. This condition is in; In some cases, it can lead to undesirable consequences. In addition, this switch does not provide remote control, i.e. a relay with switched contacts should always be in the immediate vicinity of the key, and not at the control object.

Closest to the proposed one is a key switch containing keys equipped with one group of rocker contacts, a relay according to the number of keys, a common reset key and decoupling diodes according to the number of relays. The disconnecting contacts of the keys are connected in series to the switching loop in order from the beginning to the end of the switch, the contact of the common reset key is connected sequentially to the switching cable, the closing contacts of the crossover groups are connected to the beginning of the relay windings, the closing contacts of which connect the beginning of the windings of the relay relay through decoupling diodes to the end of the loop inclusion, and the ends of the windings of all relays are connected to the output for connection to a power source [3].

This switch ensures the inclusion of any key separately; it has protection against the erroneous selection of two. objects, but ensures correct operation only when the keys are flipped to the reverse position, less than the time the relay falls off. If this condition is not met, then when the key is released, the relay will not have time to self-lock ..... and will return to the released state. And since the time for releasing the key depends on the actions of the operator, there may be difficulties in using the device.

'The purpose of the invention is improving the reliability' of the switch.

This goal is achieved by the fact that in the key switch with automatic reset, containing two conclusions For connecting to a power source, the keys with cross over contact groups, relays according to the number of keys with cross over contact groups, the opening contacts of the keys are connected in series in the loop 'inclusion in the sequence from the beginning to the end of the switch, and ..... the closing contacts are connected. to the beginnings of the windings of the corresponding relays, the canary key and each relay are provided with additional thread changeover contacts, moreover the opening contacts of the keys are connected in series to the loop of the `` ra'Vlen'ya '' sequence from the end to the beginning of the switch, and the closing contacts of these groups are connected to the ends of the windings of the corresponding relays, opening .......... contact contacts relay contact groups of the relay are connected in series to the self-locking loop in. a row from the beginning to the end of the switch, and the closing contacts of these groups are connected to the beginnings of the relay's own windings, the opening contacts of the additional changeover contact groups of the relay are connected in series to the self-locking circuit in the order from the end to the beginning of the switch, the closing contacts of these groups are connected to the ends of the relay's own windings , and the beginning and ends of the inclusion and self-locking loops are connected to the terminals' for connecting to a power source. ''

The drawing shows a circuit diagram of a key switch.

A key switch with automatic reset contains keys 1, relay 2 with contact group 3, consisting of normally open contacts 4, 5 and 6, 7, as well as normally closed 8, 4 and 9, 6 contacts. Key 1 is made in the form of a push-button switch with normally closed contacts 10, 11 and 12, 13, normally open 10, 14 and 12, 15 contacts, as well as a warning light 1.6.

The switch operates as follows. ' ¹

When any key 1 is pressed, its contacts 10, 14 and 12, 15 are closed and supply power to the coil of relay 2, which causes the contacts of contact group 3 of relay 2 to be activated, which, through its own contacts Ty-4, 5 and 6, is blocked by contacts 4 , 8 removes power from the windings of one relay group, and contacts 6, 9 turn on another relay group, thereby ensuring that any previously switched on relay is turned off.

When you accidentally press two or more keys, their contacts 10, 11 and 12, 13 open, which causes the power supply circuit to break through the keys, the relay does not turn on, and the relay that was turned on earlier remains on. This state persists as long as only one key is pressed.

Contacts of free contact groups of relays are used for switching circuits of the control object.

If it is necessary to remotely control the object, when the switched circuits must be of the minimum length, the switch allows the relay to be carried out to the control object, and the key remains on the control panel, '

Using the proposed invention will improve the reliability of the equipment, provide remote control of objects, which is achieved economic effect.

Claims (1)

. Claim A key switch with automatic reset, containing two outputs, water for connecting to a power source, keys with changeover contact groups, relays by the number of keys with changeover contact groups, opening contacts of the keys are connected in series to the switching loop in the sequence from the beginning to the end of the switch, and the closing Cong cycles are connected to the beginnings of the windings of the corresponding relays, distinguishing them. the fact that, in order to increase the reliability of the switch, each key and each relay are equipped with additional flip contact groups, and the disconnecting 5 contacts of the additional contact groups of keys · are connected in series to the control loop in order from the end to the beginning of the switch, and the closing contacts of these groups are connected to the ends of the windings of the corresponding relays, the opening contacts of the changeover contact groups of the relay are connected in series to the self-locking loop. at. order from start to con. _ the switch, and the make contacts of these groups are connected to the beginnings of the relay's own windings, the make contacts of the additional change-over relay contact groups are connected in series to the self-locking circuit in order from the end to the start of the switch, the make contacts of these groups are connected to the ends of the relay's own windings, and the ends of the inclusion and self-locking loops are connected to the terminals for connection to a power source.