SU849540A1 - Device for deflection of crt beam - Google Patents

Description

(54) DEVICE FOR REFLECTION OF BEAM ELECTRON-BEAM TUBE

I

The invention relates to radio engineering and can be used in scanning devices with electromagnetic deflection of an electron beam.

A device is known for deflecting a beam of a cathode ray tube containing a push-pull deflection coil, the windings of which are connected through the push-pull output stage to the outputs of a differential amplifier, N power supplies and two groups of keys each consisting of N switches, and the windings of the push-pull diverter coil are connected to the outputs of the first keys of the corresponding groups of keys 1.

However, the known device has a relatively high power consumption.

The purpose of the invention is to reduce power consumption.

To do this, in a known device in each of the key groups, the first input of each key is connected to the output of the subsequent key, the second key inputs of both key groups are connected in parallel to the outputs of the corresponding power sources, and the third key inputs of both key groups, except the first keys, are connected to

opposite shoulders of the push-pull output stage.

The drawing shows a structural electrical circuit of the proposed device.

The device for deflecting the beam of the electron-beam tube contains a differential amplifier 1, a push-pull output stage on transistors 2 and 3, a push-pull diverter coil with windings 4 and 5, the first group of keys consisting of N keys 6, the second group of keys consisting About from N keys 7, and N power sources 8.

The device works as follows.

When the input voltage of the differential amplifier 1 is input, corresponding to the coordinate component formed on the screen of the electron-beam tube (CRT) line, the corresponding currents are formed in the windings 4 and 5. The electromotive force of self-induction in windings 4 and 5 is determined by the rate of change of the input voltage, which corresponds to the coordinate component of the speed of movement of the beam on the CRT screen.

Claims (2)

In steady state or with relatively slow changes in current in windings 4 and 5, the potentials of the collectors of transistors 2 and 3 are close to the voltage of the first source 8, the first keys 6 and 7 are open and the push-pull output stage is powered from the first source 8. All the others Keys 6 and 7 are locked. With a slight increase in the rate of change of currents in the windings 4 and 5 of the push-pull deflection coil, the electromotive force of self-induction appears and the collector potentials of transistors 2 and 3 change. With a further increase in self-induced EMF, the collector potential of transistor 2 increases to such an extent that it exceeds the second key threshold 7, as a result, the second key 7 opens, and the first key 7 closes, disconnecting the first source 8 from the push-pull output stage. As a result, the second source 8 with a higher voltage is connected to the winding 5 and the transistor 3, which prevents the saturation mode in the transistor 3. When it is higher than the current rate, the third key 7 is opened, the third source is connected to the output stage the closing second key 7 disconnects the second source 8 from the push-pull output stage. At maximum line forming speeds and at the transition of a CRT beam from one point of the screen to another, N key 7 is opened, as a result, winding 5 and transistor 3 connect KN to source 8 of the highest voltage. At opposite line-forming voltages, the EMF sign of both arms of the output stage changes to the opposite one and, similarly to the above, N keys are controlled with 6 sets; 7; а „р7з;: ГГ1е„ and „Тк the vector of transistor 2 remains close to the potential of the first source 8, which prevents the saturation of the transistor 2. Thanks to the stepwise control of the voltage of the power supply of the push-pull output ascade, complete utilization of the sources is achieved, which excludes excessive power losses. The proposed device allows lower power consumption, has a simple circuit and high reliability. An apparatus for deflecting a beam of a cathode ray tube comprising a push-pull diverter coil, the windings of which through a push-pull output stage are connected to the outputs of a differential amplifier, N power sources and two groups of keys, each consisting of N Gyuchi, and a winding duplex deflecting coil The first keys of the corresponding groups of keys are connected to vb, characterized in that, in order to reduce power consumption, in each of the groups of keys the first input of each key is connected to the output after the next key, the second key inputs of both key groups are paired in parallel to the outputs of the corresponding power sources, and the third key inputs of both key groups, except the first keys, are connected to the opposite arms of the push pull output stage. Sources of information taken into account in the examination 1. US patent number 3859557, H; h.5