JPS5915135Y2 - pulse modulator - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a pulse modulator, particularly to its overload protection circuit.

The first pulse modulator with conventional overload protection circuit
There was something shown in the figure.

In the figure, 1 is a DC power supply, 2 is a charging circuit, 3 is a shunt circuit, 4 is a switching element such as a thyratron, 5 is a pulse shaping circuit (hereinafter referred to as PFN), 6 is a load such as a klystron, 7 is a gate circuit, and 8 9 is a trigger oscillator, and 9 is an overload detection circuit.

Next, the operation will be explained.

The DC voltage of the DC power supply 1 is charged to the PFN 5 through the charging circuit 2.

When the trigger from the trigger oscillator 8 passes through the gate circuit 7 and fires the switch element 4 such as a thyratron, P
The charge stored in FN5 is discharged through the circuit 5-4-6, and a pulse determined by PFN5 is generated in the load 6.

If an abnormality occurs in the load 6 and an overcurrent flows, the overload detection circuit 9 detects the overload, opens the gate circuit 7, and no trigger is supplied to the switch element 4.

In this way, an abnormality in the load is detected, the trigger is stopped, and no pulse output is generated.

In addition, the shunt circuit 3 is closed due to overcurrent that occurs during abnormality.
This is to discharge the reverse charge stored in N5.

Conventional devices connect the overload protection circuit directly to the load circuit for detection, so it is necessary to detect the peak value of the pulse, which has the disadvantage of making the gate circuit complicated and expensive. .

This invention was developed to eliminate the above-mentioned drawbacks of conventional devices, and aims to provide a distant relative of overload protection in a simple and inexpensive manner.

An embodiment of this invention will be described below in detail with reference to the drawings.

That is, in FIG. 2, reference numeral 10 denotes an overload detection device which detects the voltage generated in the resistor by the current flowing through the shunt circuit 3 and opens the gate and circuit 7 accordingly, and is constituted by, for example, a relay.

The relay contact output of this overload detection device is supplied to a gate circuit 7 to open and close this gate circuit 7.

Note that 1 to 8 are the same as the conventional one.

In the device configured as described above, the reverse charge stored due to an abnormality in the load is discharged from the PFN 5 through the shunt circuit 3.

Therefore, the overload detection device 10 detects the voltage generated in the resistance of the shunt circuit 3, opens the gate circuit 7, blocks the trigger from being supplied to the switch element 4, and stops the pulse output as in the conventional case. There is.

The current waveform flowing through this shunt circuit 3 is not a pulse waveform, but a waveform having a time constant RC due to the capacitance C of the PFN 5 and the resistance R of the shunt circuit 3.The overload detection device 10 is simple and sufficient to use a detection method such as a relay. It will be cheaper.

In the above embodiment, the relay contact output of the overload detection device 10 is supplied to the gate circuit 7, but the relay of this detection device itself may be used as a gate circuit.

As described above, according to this invention, overload is detected by the current of the shunt circuit, so there is no need for complicated pulse peak detection, and the protection circuit can be constructed simply and at lower cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a pulse modulator having a conventional overload protection circuit, and FIG. 2 is a circuit diagram of a pulse modulator according to an embodiment of this invention. In the figure, 1 is a DC power supply, 2 is a charging circuit, 3 is a shunt circuit, 4 is a switch element, 5 is a pulse shaping circuit, 6 is a load, 7 is a gate circuit, 8 is a trigger oscillator, and 10 is an overload detection device. be. Note that the same symbols in the figures indicate corresponding parts.

Claims (1)

[Scope of utility model registration request] A pulse shaping circuit that accumulates charge, a switch element that discharges the charge accumulated in this pulse shaping circuit through a load by being electrically connected, and a shunt that discharges the reverse charge accumulated in the pulse shaping circuit in the event of an overload. and an overload detection device that detects the current flowing through the shunt circuit, and the operation of the overload detection device stops the conduction of the switch element and stops the pulse output to the load. vessel.