SU840986A1 - Prewarning device - Google Patents

Description

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The invention relates to automation and alarm systems and can be used to provide a leading warning signal before starting individual machines or a complex of machines.

Preventive alarm devices are known that contain a rectifying bridge, one diagonal of which is connected to a voltage regulator of the actuator, a blocking relay, the first closing contact of which is connected to a circuit of a series-connected starting relay and the first switch and is bridged by the starting contact of a starting relay, sound generator, switch, second and third keys, time relays and acoustic emitters, energy storage device and rectifier, with a successor to another rectifying bridge diagonal o with its own disconnecting contact, a blocking relay is connected, in parallel to the opening contact of which a sound generator, a switch and a time relay connected to the input of the first key are connected in parallel, the outputs of the second and third keys are connected to the corresponding acoustic radiators, the first inputs of these keys are connected to the switch, and the second to the sound generator, which is connected in series with the blocking relay through its second closing contact and via a rectifier to the drive nergii connected between the first key and make contact bloki0 ruyuschego relay 1.

However, in the devices, the warning signal is monitored by the total current of all acoustic emitters and

5 signal generators flowing through a blocking relay. If at least one acoustic radiator or signal generator fails, the device does not generate a signal for

0 starting the running machine. In addition, it is difficult to match the operation current of a blocking relay with the total current of all acoustic emitters. When it changes

5 the number of acoustic emitters or the use of other types of emitters need to replace the blocking relay. The winding of the blocking relay and its contacts operate under severe conditions, since the total current of all acoustic emitters and the signal generator flows through its winding, and its contacts commute this current. With a large number of acoustic emitters, their total current reaches a considerable amount. This causes the low reliability of this device with a large number of acoustic emitters. The closest in technical solution to the present invention is a device for warning signaling containing rectified mi-. A single bridge, one diagonal connected to the power transformer, and the second diagonal connected to one of the time relays, the thyristor anode of which is connected to the power transformer, the thyristor control electrode, connected via a series-connected time relay contact, a diode and a button to the power transformer, acoustic and light signaling devices 24. This device provides control of the warning signal supply by each acoustic emitter. However, if at least one acoustic radiator or their circuits fail, the device does not issue permits to start the machine, which reduces the reliability of the device. In addition, the number of cable cores for powering acoustic emitters, equal to the number of acoustic emitters plus one total, reduces reliability and increases the cost of the device itself. The purpose of the invention is to improve the reliability of the warning signal device. The goal is achieved by the fact that a warning device containing a rectifying bridge, one diagonal of which is connected to the power transformer, one output of the second diagonal of the rectifying bridge, is connected to the time relay, the end contact of which is connected to the circuit of the intermediate relay of the actuator, j, a thyristor, the anode of which is connected to the power transformer, the control electrode of the thyristor through a series-connected disconnecting contact of a time relay, a diode and a start button is connected to the transform The power supply and acoustic and light signaling devices, a blocking relay and a potentiometer are inserted, acoustic and light signaling devices are connected in parallel and connected to the power transformer via serially connected thyristors and a potentiometer to the middle output of which is an active blocking relay, the first closing contact which is connected between the time relay and the other output of the second diagonal of the rectifying bridge, and the second Z1 contact switch of the blocking relay is connected in parallel with the start button. The drawing is a schematic diagram of the warning signal device, the device contains a rectifying bridge 1, one diagonal of which is connected to power transformer 2, time relay 3, with closing contact 4, potentiometer 5, the blocking relay b of which is connected to the slider, the first closing contact 7 of which included in the time relay circuit, and the second closing contact 8 is connected in series with the disconnecting contact 9 of the time relay and included in the control circuit of the thyristor 10, acoustic 11 and light 12 signaling devices interconnected in parallel, the start button 13, the diode 14, the closing contact 15, the resistor 16, the diode 17, the button 18 and the intermediate relay 19 of the actuator 20. The device works as follows. To start the machine, for example, a conveyor, the start button 13 is briefly pressed. In this case, a control voltage is applied to the control electrode of the thyristor 10. The thyristor 10 is opened and the acoustic emitters 11 and signal lamps 12 are powered through the potentiometer 5. When the acoustic emitters 11 and signal lamps 12 are in good condition, as well as their circuits, the voltage removed from the slider of potentiometer 5 is enough to turn on the blocking relay b. The blocking relay 6 is turned on and the first closing contact 7 starts the time relay 3, and the second closing contact 8 shunts the button 13. When the warning signal expires, time 3 switches on, which closing contact 4 turns on the intermediate relay 19 of the actuator 20, and disconnects 9 breaks the thyristor control circuit 10. The thyristor 10 closes and the warning signal ceases. In this case, the blocking relay b is disconnected and its first closing contact 7 breaks the power supply circuit of the relay 3 times. Due to diode 14, relay 3 is turned off with a certain shutter speed, which ensures reliable activation of intermediate relay 19 of actuator 20. After switching on intermediate relay 19, with its closing contact 15 it self-blocks through diode 17 and resistor 16. Termination of device operation before activating actuator 20 is performed by momentary pressing stop button 18.

The potentiometer slider 5 is set in such a position that, when the number of acoustic emitters 11 and signal lamps 12 are operable in advance, the voltage taken from the slider of potentiometer 5 is sufficient to turn on the blocking relay 6. If the acoustic emitters 11 are faulty, the signal lamps 12 are greater than the specified value or the failure of their circuit decreases the current, the potentiometer 5 leads and the voltage taken from its slider will be insufficient to turn on the blocking relay b, and the permission to start is not steps.

The use of one common thyristor for powering signal devices, a potentiometer and a blocking relay connected to the potentiometer slider increases the reliability of the device by 30-40% and reduces its cost 1.3-1.4 times by reducing the series-connected elements and reducing lived power cable signaling devices. In addition, in this device without changes in the circuit and the inclusion of additional elements, it is possible to adjust the circuit depending on the type of signaling devices used and their number, as well as to monitor the health of signaling devices.

Claims (2)

1. Authors certificate of the USSR 414610, cl. G 08 B 21/00, 1972. 2.Irib E.E. and others. Circuit control circuit warning signal for coal combines. Mechanization and automation of production, 1973, No. 9 (prototype). 9 I: 7fO