SU720798A1 - Device for automatically switching on tv set - Google Patents

Description

The invention relates to television and can be used in television equipment of a reception or video control channel.

A device for automatically turning off the TV is known, which contains a turn-on relay with normally-open contacts and self-blocking contacts connected in parallel with the switch, and the turn-on relay winding is connected to the power supply by one output and the switch to the first release of the on / off relay through a switch connected and the relay contacts, with one open contact and one self-closing contact of the activation relay; s to the power supply terminal and the second terminal of the switch, the DC power formed on the common-emitter transistor, the collector of which is connected to one terminal of the relay coil turn-off, turn off the other terminal of the relay coil connected to the straightening Shtele 1.

However, this device has a complex scheme.

The purpose of the invention is to simplify the device by eliminating thermal relays.

To achieve this goal, an automatic TV shutdown device containing a turn-on relay with normally open contacts and self-blocking contacts connected in parallel with the switch, while the winding

the on relay is connected by one output to the power source, and the other output to the first output of the switch and the self-blocking contact of the inclusion relay through a series-connected switch and contacts of the activation relay, one

the open contact and one contact of the self-blocking contact of the on relay are connected to the output of the power source and the second output of the switch, a DC amplifier made on a common-emitter transistor to the collector of which is connected to the output winding terminal of the off relay, the other winding of the off relay is connected to the key, entered the key executed on the transistor, to

the collector of which is connected to the base of the dc amplifier through the introduced integrating RC-chain, with a positive polarity signal being fed to the base of the transistor through the input of a series-connected resistor and capacitor op.

The drawing shows a circuit diagram of the proposed device.

The device automatically turns off the TV contains a relay 1 on, a switch 2, a power source 3, a DC amplifier on transistor 4, a switch off relay 5, a rectifier b, a switch on transistor 7, resistors 8-11, diode 12, capacitors 13-16, contacts 17, 18, 19.

The device works as follows.

When the switch 2 is turned on, the power supply circuit closes and the relay 1 operates, closes contact 19 and contact 18, which provides connection to the source 3 of two 31V outputs, connected through switch 2 to the source 3.

The collector circuit of the transistor 4 is powered by a filament voltage b, 3 V through the rectifier 6, and the capacitor 15 is smoothing. ,

Until the TV is fully heated, the transistor 7 remains in a de-energized state. Transistor 4 is also locked because its base is grounded through resistors 9, 8 and diode 12.

With the TV set warming up, the input signal of positive polarity enters the input and the transistor 7, and the horizontal scanning pulses rectified by the diode 12 enter the collector circuit of transistor 7, the potential of its collector becomes close to zero and the transistor 4 continues to remain in the locked state . Thus, during normal operation of the TV, the current is consumed only by the transistor 7 and relay 1. The transistor 4 and relay 5 do not consume current.

When BTOeutftrHanatplflsHctdp 7 disappears, the capacitor 14 starts to charge, the transistor 4 opens, the relay 5 is activated and the contacts 19 open. The power circuit of relay 1 opens and Contacts 17 and 18 return to the normally open position. The power supply of the television through pin 17 is broken and the television turns off. The contacts 19 are returned to the normally closed position, and the device for automatically turning off the TV returns to its original position.

The RC circuit (8, 14) in the load of the transistor 7 serves to prevent the device from tripping in case of a short video signal loss: when the transistor 7 is locked, the voltage on the capacitor plates 14 gradually increases and approaches the unlock potential of the transistor 4. The time of this increase depends on the constant this time f RC.

If the video signal at the input resumes before this time expires. Then transistor 7 will open, and capacitor 14 will begin to discharge. In this case, the transistor 4 oq is in the closed state, and the relay 5 is not

will work to open contacts 19.

The proposed device is much simpler than known devices.

Claims (1)

Invention Formula A TV auto-shutdown device containing a turn-on relay with normally-open contacts and self-blocking contacts turned on i is parallel to the switch, while the winding of the on relay is connected to one power source and one other terminal; to the first terminal of the switch and the self-blocking contact of the on relay through the series-connected switch and relay contact, with one open-contact terminal and one self-blocking contact the enable relay is connected to the power supply output and the second output of the switch, 5 DC amplifier, made on a common emitter transistor, to the collector of which one switch winding terminal is connected, another switch relay winding jack is connected to a rectifier, characterized in that, in order to simplify the device by eliminating the thermal switch, a key is made on the transistor, to the collector of which the base of the DC amplifier is connected through the introduced RC integrating circuit, with S A positive polarity video signal is applied to the base of the transistor through a series-connected resistor and a capacitor, and positive horizontal line impulses, sweeps through a series-connected diode and a resistor, are applied to the transistor collector. Sources of information taken into account in the examination 1. US patent No. 3541453, cl. 325-364, 1970 (prototype).