JPH02231956A - Radiation monitoring power supply - Google Patents

Abstract

PURPOSE:To cut a noise component by inputting a pulse signal having the same pulse width as the width of a switching noise generated simultaneously with the generation period of said noise to a make and break switch and by cutting OFF the voltage supply to an amplifier only during said pulse width. CONSTITUTION:A pulse signal having the same width as the width of a switching noise of a switching stabilization power supply 10 and transmitted simultaneously with the generation period of said noise is inputted to a make and break switch 11 to cut OFF the voltage supply to an amplifier 2 only during said pulse width. In this manner, it is possible to cut a noise component included in a stabilized voltage V2. Further, the cut voltage part is supplied by a supplementary capacitor C1 so that a stabilized voltage of a flat waveform can be supplied to said amplifier 2.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a power supply device for a radiation monitor equipped with a switching stabilized power supply, and in particular to a power supply device for amplifying minute radiation detection signals. The present invention relates to a radiation monitor power supply device that obtains a DC voltage for stably operating an amplifier.

(Prior Art) Generally, a radiation monitor device inputs a radiation detection signal detected by a radiation detector to an amplifier, amplifies it to a predetermined level, and then guides it to a trip circuit, a signal output instruction section, etc.
The radiation situation is being monitored.

By the way, since the radiation detection signal detected by the radiation detector is a very small signal, the amplifier that amplifies the very small signal is set to a high gain. Therefore, if the power supply voltage supplied to such an amplifier contains noise,
If power supply voltage noise is superimposed on the radiation detection signal and the noise-containing radiation detection signal is amplified in this state, the trip circuit may erroneously output a trip, or the signal output instruction section may indicate an incorrect radiation measurement value. This may cause inconveniences such as

Therefore, a power supply device for a radiation monitor must be equipped with sufficient noise removal measures. Conventionally,
From the above point of view, a device as shown in FIG. 3 is used. That is, this device uses a dropper-type stabilized power supply 1 with little ripple to convert a DC power supply voltage of, for example, 25V.
The voltage is converted into a stabilized voltage of 15V by the converter C, and after being smoothed by the capacitor C, it is supplied to the amplifier 2 of the minute signal system.

However, since the dropper type stabilized power supply 1 is configured to obtain a drop voltage using a resistor element, it is often converted into thermal energy by the resistor element, and therefore it is necessary to perform heat dissipation treatment.

Therefore, it has been considered to use a switching type stabilized power source that does not require heat dissipation treatment in place of the dropper type stabilized power source. However, although this switching type stabilized power supply is effective in that it does not generate thermal energy, on the contrary, high frequency noise is generated due to switching, so it becomes necessary to remove the high frequency noise. Therefore, a smoothing capacitor is used to remove high-frequency noise, but the reality is that it is still not possible to sufficiently remove ripple components that occur due to switching.

[Problem to be solved by the invention]

Therefore, as described above, the radiation monitor power supply device has a problem in that ripple components due to switching cannot be sufficiently removed when a switching type stabilized power supply is used.

The present invention has been made in view of the above-mentioned circumstances, and is a radiation monitor that can sufficiently remove ripple components contained in the stabilized voltage generated by a switching stabilized power supply, thereby making it possible to monitor radiation measurement values with high precision. The purpose is to provide a power supply device.

[Structure of the Invention [Means for Solving the Problems] In order to achieve the above object, the present invention provides an amplifier that amplifies a radiation detection signal detected by a radiation detector by using a stable output signal from a switching stabilized power supply. A radiation monitoring power supply device that supplies a switching voltage includes a switching stabilized power supply that transmits a pulse signal set to the same pulse width as the ripple width generated by switching in synchronization with the switching transmission cycle, and this switching stabilized power supply. a switching means provided between the amplifier and the amplifier for cutting off voltage supply to the amplifier by a pulse width of a pulse signal output from the switching stabilized power supply; and voltage replenishment means for supplying the necessary amount of voltage to the motor.

(Operation) By taking the above measures, in response to a pulse signal that has the same width as the ripple width included in the stabilized voltage generated by the switching stabilized power supply and is transmitted in synchronization with the switching generation cycle, Since the cutoff means cuts off the voltage supply to the amplifier, the ripple component included in the stabilized voltage is cut. Since the cut voltage is compensated for by the supplementary capacitor, the ripple component is sufficiently removed and a stabilized voltage exhibiting a flat waveform can be supplied to the amplifier.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows the radiation monitor power supply (hereinafter referred to as the "power supply").
FIG. 2 is a diagram showing the configuration of a computer. This power supply is
A switching stabilized power supply 10, an on/off switch 11 provided between the switching stabilized power supply 10 and an amplifier 2 that amplifies a minute radiation detection signal output from the radiation detector S, and the on/off switch 11 and the amplifier. 2, a replenishment capacitor C1 serving as a voltage replenishment means for supplying the voltage cut by the on-off switch 11;
It is constituted by a smoothing capacitor C2 provided between a switching stabilized power supply 10 and an on/off switch 12.

The switching stabilized power supply 10 switches the power supply voltage V1 output from the power supply at a predetermined oscillation cycle to convert it into a stabilized voltage v2, and also adjusts the width of switching noise (ripple) generated in the stabilized voltage due to switching. A pulse signal with the same pulse width is transmitted in synchronization with the switching transmission cycle and supplied to the open/close switch 11. The open/close switch 11 is a semiconductor switch or the like, and is controlled to open or close by a pulse signal output from the switching stabilized power supply 10, and is turned off only during the pulse width to cut off the supply of stabilized voltage to the amplifier 2. . The replenishment capacitor C1 has a sufficient capacity to replenish the voltage cut when the on-off switch 11 is turned off.

Therefore, according to the power supply device configured as described above, the switching stabilized power supply 10 performs the switching operation as shown in FIG.
Stabilized voltage v2 including switching noise like point waveform
A pulse signal (waveform at point B in Fig. 2) having the same pulse width as the noise contained in the stabilized voltage V2 and synchronized with the noise generation cycle is obtained, and this pulse signal is sent to the open/close switch 11. supply As a result, open/close switch 1
1 opens and closes at the timing shown in FIG.

That is, it is turned off only during the pulse width to cut noise components included in the stabilized voltage. The voltage for this cut is compensated by the discharge of the supplementary capacitor C1, and the waveform at point C becomes a flat waveform as shown in FIG. 2, containing almost no switching noise.

For example, the consumption current i in the amplifier 2 is 50 smA, the off time Δt of the open/close switch 11 is 2 μs, and the supplementary capacitor C
When the capacitance of 1 is 10 μF, the ripple voltage Vr becomes Vr=Q/C−iΔt/C −50X10−3X2 X10−6/IOXIO−6 key 10 m V. That is, the ripple voltage becomes 1/10 or less.

Note that the output of the switching stabilized power supply 10 is directly supplied to loads such as relays, lamps, etc., which consume a large amount of current and for which ripples due to switching are not a problem, without going through the on/off switch 11.

According to the above embodiment, a pulse signal having the same pulse width as the switching noise width of the switching stabilized power supply 10 and transmitted in synchronization with the noise generation cycle is input to the open/close switch 11. Since the voltage supply to the amplifier 2 is cut off only during the pulse width, the noise component contained in the stabilized voltage v2 can be cut.

Moreover, since the cut voltage is supplemented by the supplementary capacitor C1, switching noise is sufficiently removed and a stabilized voltage exhibiting a flat waveform can be supplied to the amplifier 2. Therefore, by using such a radiation monitor power supply device, radiation measurement values can be measured with high precision.

Note that the present invention is not limited to the above embodiments,
Various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to sufficiently remove the ripple component contained in the stabilized voltage generated by the switching stabilized power supply, and therefore radiation measurement values can be obtained with high accuracy. A radiation monitor power supply device that can be monitored can be provided.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a radiation monitor power supply device that is an embodiment of the present invention, Figure 2 is a waveform diagram at various points in the radiation monitor power supply unit, and Figure 3 is a configuration diagram of a conventional dropper set stabilization circuit. It is. 2... Amplifier, 10... Switching stabilization circuit,
11... Open/close switch, C1... Replenishment capacitor.

Claims (1)

[Claims] In a radiation monitor power supply device that supplies a stabilized voltage that is the output of a switching stabilized power supply to an amplifier that amplifies a radiation detection signal detected by a radiation detector, the width of the ripple caused by switching and the A switching stabilized power supply that transmits a pulse signal set to the same pulse width in synchronization with a switching transmission cycle, and a pulse signal that is provided between the switching stabilized power supply and the amplifier and output from the switching stabilized power supply. The present invention is characterized by comprising: switching means for cutting off the voltage supply to the amplifier by a pulse width of A power supply device for radiation monitors.