JPS6254229B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a device for controlling the tuning frequency of a high-frequency electron tube klystron. In particular, the frequency tuning of the klystron as the frequency changes requires good reproducibility of amplitude-frequency characteristics, e.g.
This invention relates to a klystron preset tuner incorporated in a high frequency power amplifier or the like.

[Description of prior art]

In klystron power amplifiers used for satellite communications or satellite tracking and control, the cavity tuning control of the klystron that involves changing the transmission frequency has good reproducibility due to simple circuitry and easy operation, and is A preset tuner that is easy to operate is desired. For this reason, a pulse motor and a pulse detection mechanism have been connected to the tuned axis of the klystron cavity, and a microcomputer (CPU) has been used to control it, and the tuned position of the cavity has been made to correspond to the amount of rotation of the pulse motor. The preset tuner was controlled using a so-called digital control system.

However, this method requires a complex pulse detection mechanism consisting of, for example, a gear-shaped light shielding plate and a photo interrupter, and the CPU calculates the number of drive pulses for the pulse motor from preset pulse data for each cavity. Load it into a counter and send a drive pulse to the motor, then detect that the motor is driven accurately by the pulse, monitor it with the counter and CPU, and stop the pulse motor when it reaches a preset value. In order to execute a series of controls, a program necessary for this control must be provided. Furthermore, since a CPU is used in the control system, it is necessary to take measures against fluctuations in the power supply voltage, especially runaway programs that occur during momentary power outages. Furthermore, it is extremely difficult to perform emergency operations when the control system becomes inoperable due to failure of the pulse motor or CPU.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a preset tuner that is simple, inexpensive, and easy to operate in an emergency for frequency tuning control of a klystron in response to frequency changes.

[Key points of the invention]

The present invention includes a potentiometer for detecting the tuning position that is linked to each cavity tuning shaft of a klystron, a DC motor that is directly connected to one end of a tuning rod that is mechanically detachable from the tuning shaft, and a tuning position detection potentiometer that is connected to each cavity tuning shaft of the klystron. The present invention is characterized by an analog control system having a feedback loop, by means of a control section comprising a drive circuit, a comparison circuit, and an operation/display circuit that control the motor in accordance with the amount of rotation of the DC motor.

[Explanation based on examples]

Embodiments of the present invention will be described in detail with reference to the drawings.

The figure is a configuration diagram of an embodiment of the present invention. In the cavity 1 of the klystron there is a tuning shaft 2 to which an interlocking gear 3 is attached. The rotation shaft of the potentiometer 4 is rotated in conjunction with the gear 3. A tuning rod 5 is provided which is mechanically detachable from the tuning shaft 2, and a DC motor 6 is directly connected to the tuning rod 5. This motor 6 is controlled by a control section consisting of a drive circuit 7, a comparator circuit 8, and an operation display circuit 9. Most of the potentiometers 4 are built into the klystron body.

A potentiometer 4 is interlocked with the tuning shaft 2 via a gear 3 to detect the tuning position, and generates a voltage at a terminal A corresponding to this position. The DC motor 6 has its rotating shaft directly connected to the tuning rod 5,
It is constructed so that it can be easily attached and detached from the tuning shaft 2 on the klystron side and the connecting portion B. The drive circuit 7 receives the pulse signal sent from the comparator circuit 8 and switches the polarity of the DC motor 6.
Rotate forward and reverse. The comparison circuit 8 compares the voltage generated by the tuning position detection potentiometer 4 with a preset voltage, further determines the polarity of the error voltage, and sends both forward and reverse pulses to the next stage drive circuit 7. . The operation display circuit 9 includes a reference voltage setting potentiometer for presetting the desired position of each cavity, a channel selection switch, a cavity position adjustment switch, and a light emitting diode for displaying rotation stop of the DC motor and its direction. Consists of etc.

When a certain channel is selected from the operation display circuit 9, a reference voltage setting potentiometer in the operation display circuit supplies a preset value signal to the comparison circuit 8. This voltage is compared with the position detection signal fed back from the potentiometer 4, and an error output is sent out. This error output activates the drive circuit 7 to rotate the DC motor 6. As the DC motor 6 rotates, the error output gradually becomes smaller, and when this output becomes zero, the DC motor 6 stops rotating. This reproduces the exact tuning position of the selected channel.

[Explanation of effects]

As described in detail above, according to the present invention, the circuit configuration is simpler than the system using a CPU for the control system. There is no need to take any measures against power supply voltage fluctuations, especially runaway programs during instantaneous power outages. Also,
The drive motor and tuning rod are integrated and attached to the outside of the klystron, making it easy to attach and detach from the klystron, so even if the control system is disabled, tuning can be performed manually using a conventional manual tuning rod. Furthermore, when tuning by manual operation, it is possible to measure the resistance value of the potentiometer for detecting the tuning position using a tester, etc., without using a dedicated measuring device to measure the amplitude-frequency characteristics of the klystron. If you set it to the value recorded in advance,
Easily adjustable to desired tuning position. Therefore, the synchronization operation in an emergency becomes very easy.

[Brief explanation of the drawing]

The figure is a configuration diagram of a preset tuner of a klystron according to an embodiment of the present invention. 1... Klystron cavity, 2... Cavity tuning axis, 3... Gear, 4... Potentiometer, 5
... Tuning rod, 6 ... DC motor, 7 ... Drive circuit, 8 ... Comparison circuit, 9 ... Operation display circuit.

Claims (1)

[Scope of Claims] 1. A potentiometer for detecting a tuning position that is linked to the rotation of a cavity tuning shaft of a klystron; A tuning rod configured to be mechanically detachable from the cavity tuning shaft; This tuning rod; A DC motor to which the drive shaft is directly connected, a drive circuit that supplies a forward or reverse drive current to the DC motor, an operation display circuit that provides a set value by operation, and a set value that is sent from this operation display circuit. A klystron preset tuner comprising a comparison circuit that compares the signal with a position detection signal obtained from the potentiometer and controls the drive circuit based on the error output.