A multi-channel coincidence electronics system with adjustable output pulse width

Abstract

The present invention provides a multi-channel coincidence electronics system with adjustable output pulse width. The system comprises a circuit board and a DC input interface, a signal input interface, a signal output interface, a power supply module, a signal processing module, and an LED module, all of which are arranged on the circuit board. The power supply module comprises an external 5V power adapter, an input protection chip connected to the 5V power adapter, and a reverse charge pump connected to the input protection chip. The signal processing module comprises a reference voltage generator, a discriminator connected to the reference voltage generator, an AND gate connected to the discriminator, and a pulse width regulator connected to the AND gate. The LED module comprises a 5V power indicator light, a -5V power indicator light, and a coincidence detection indicator light connected to the output signal. The present invention not only simplifies the electronics system and reduces its cost, but also enables convenient adjustment of the pulse width of the output signal, making the present invention highly practical and applicable.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-channel coincidence electronics systems, in particular to a multi-channel coincidence electronics system with adjustable output pulse width. Background Art

[0002] A multi-channel coincidence electronics system is an electronic system that uses multiple channels for signal processing and amplification. This system is typically used to collect, process, and analyze signals from multiple sensors, improving the efficiency and accuracy of signal processing. Traditional analog multi-channel coincidence measurement systems consist of a front-end amplifier, a delay adjustment circuit, a coincidence circuit, a gated peak-sensitive ADC, and a multi-channel computer. However, existing coincidence measurement electronics systems are relatively complex and expensive, requiring extensive technical support and management, and are not suitable for pure counting experiments following simple coincidence measurements. Therefore, the present invention proposes a multi-channel coincidence electronics system with adjustable output pulse width to address the above-mentioned problems. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a multi-channel electronic system with adjustable output pulse width, which not only simplifies the electronic system and reduces the cost of use, but also can conveniently adjust the pulse width of the output signal, making the present invention highly practical and applicable.

[0004] To achieve the above objectives, the present invention provides the following solution: a multi-channel coincident electronics system with adjustable output pulse width, comprising: a circuit board and a DC input interface, a signal input interface, a signal output interface, a power supply module, a signal processing module, and an LED module provided on the circuit board, wherein the power supply module, the signal processing module, and the LED module are interconnected;

[0005] The power supply module is used to connect an external power source to power the various chips on the circuit board. The power supply module includes an external 5V power adapter, an input protection chip connected to the 5V power adapter, and a reverse charge pump connected to the input protection chip;

[0006] The signal processing module is used to process an external input signal, and the signal processing module includes a reference voltage generator, a discriminator connected to the reference voltage generator, an AND gate connected to the discriminator, and a pulse width modulator connected to the AND gate;

[0007] The LED module is used to display the signal processing status, and the LED module includes a 5V power indicator light, a -5V power indicator light, and a coincidence detection indicator light connected to the output signal.

[0008] Optionally, the 5V power adapter is used to connect to the DC input interface and, after being protected by the input protection chip, to power each chip on the circuit board;

[0009] The input protection chip is used to protect the chip safety. When the input voltage of the power supply is greater than 6.1V, the input protection chip turns off its internal transistor to cut off the power input;

[0010] The inverting charge pump is used to convert the input 5V voltage into a -5V voltage, and provide positive and negative 5V voltages to the discriminator and the reference voltage generator for positive and negative 5V power supply.

[0011] Optionally, the reference voltage generator is composed of an operational amplifier, a fixed resistor and an adjustable resistor. The reference voltage generator is used to use the fixed resistor and the adjustable resistor to divide the voltage to obtain a reference voltage, and provide the reference voltage to the discriminator as a threshold for comparing the external input signal; wherein, the value of the reference voltage can be adjusted by the adjustable resistor, and the reference voltage is -50mV.

[0012] Optionally, the discriminator includes an inverting input terminal connected to the reference voltage generator, a positive input terminal connected to the signal input interface, a positive output pin, a complementary output pin, two complementary output channels connected to the AND gate, and an operational amplifier arranged inside the discriminator.

[0013] Optionally, in the discriminator:

[0014] The operational amplifier is used to compare the reference voltage and the input signal voltage and convert the input signal into a TTL signal. When the input signal voltage is lower than the reference voltage, the positive output pin of the discriminator outputs a high level. When the input signal voltage is higher than the reference voltage, the positive output pin of the discriminator outputs a low level.

[0015] The complementary output channel is used to output a signal complementary to the positive output pin using the complementary output pin. When the positive output pin outputs a high level, the complementary output pin outputs a low level. When the positive output pin outputs a low level, the complementary output pin outputs a high level.

[0016] Optionally, the AND gate is used to perform signal matching. When the AND gate is connected to the positive output pin, it matches multiple channel signals. When the AND gate is connected to the complementary output pin, it performs anti-matching and transmits the matched TTL signal to the pulse width modulator.

[0017] Optionally, the pulse width regulator is composed of a monostable multivibrator and is externally connected to a capacitor and a resistor. The pulse width regulator is used to use the monostable multivibrator to receive a TTL signal that has passed the test, and use the time constant of the external capacitor and the external resistor to extend the pulse width of the TTL signal that has passed the test to the nanosecond to millisecond level. The signal with extended width is output through the signal output interface.

[0018] Optionally, the 5V power indicator light is used to light up when the external power supply is normally supplying power to the circuit board;

[0019] The -5V power indicator light is used to light up when the reverse charge pump normally generates a -5V voltage;

[0020] The coincidence detection indicator light is used to indicate the signal of the passage of cosmic ray muons. When a cosmic ray muon passes through the signal processing module, the signal processing module outputs a pulse with a length of 5 microseconds. During the high level period of the 5 microsecond pulse, the coincidence detection indicator light is on.

[0021] Optionally, the power input pins of each chip on the circuit board are provided with filter capacitors to improve stability.

[0022] The present invention provides a multi-channel coincident electronics system with adjustable output pulse width, and discloses the following technical effects:

[0023] 1. Portability: The circuit of the present invention contains a voltage conversion module. Although the components inside the circuit require different voltages (+5V and -5V), it can operate stably by simply connecting to the +5V voltage through the DC input interface. The 5V voltage is very easy to obtain, either through a 220V AC to 5V DC converter or by a battery. In addition, the entire circuit board is only 10cm*8cm in size and weighs only about 100g, greatly increasing its portability and scalability.

[0024] 2. Low cost: The present invention can adopt circuit components with high production volume and wide application in the market, and the overall material cost is low. At the same time, the circuit structure of the present invention is simple and does not require the design of a multi-layer PCB board, further reducing the cost of PCB manufacturing and SMT welding.

[0025] 3. Applicable to various working scenarios: The present invention can adjust the reference voltage of the discriminator and the output signal pulse width through adjustable resistors, thereby adapting to the needs of various different types of input and output signals; the present invention can also conveniently adjust the number of channels, and adjust each channel to conform or anti-conform through jumper operation (that is, by selecting the output signal of the discriminator), which enables the present invention to match a variety of different working scenarios.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a system architecture diagram provided for Example 1 of the present invention;

[0029] Figure 2 This is a system architecture diagram provided for Example 2 of the present invention;

[0030] Figure 3 A circuit diagram of a power supply module provided in Example 2 of the present invention;

[0031] Figure 4 A circuit diagram of a signal processing module provided in Example 2 of the present invention;

[0032] Figure 5 A circuit diagram of a reference voltage generator provided in Example 2 of the present invention;

[0033] Figure 6 A circuit diagram of a discriminator provided in Example 2 of the present invention;

[0034] Figure 7 A schematic diagram of an AND gate logic circuit provided in Example 2 of the present invention;

[0035] Figure 8 A circuit diagram of a pulse width modulator provided in Example 2 of the present invention;

[0036] Figure 9 This is a circuit diagram of the LED indicator light provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] like Figure 1 As shown, the present invention provides a multi-channel electronic system with adjustable output pulse width, comprising a circuit board and a DC input interface, a signal input interface, a signal output interface, a power supply module, a signal processing module, and an LED module disposed on the circuit board, wherein the power supply module, the signal processing module, and the LED module are interconnected. The power supply module supplies power to the signal processing module and the LED display module. After the external input signal is processed by the signal processing module, it is displayed on the LED display module and output via an SMA interface. Both the signal input interface and the signal output interface are SMA interfaces.

[0041] 1. The power supply module is used to supply power to each chip on the circuit board through an external power supply. The power supply module includes an external 5V power adapter, an input protection chip connected to the 5V power adapter, and a reverse charge pump connected to the input protection chip.

[0042] The 5V power adapter is used to connect to the DC input interface and, after being protected by the input protection chip, to power each chip on the circuit board;

[0043] The input protection chip is used to protect chip safety. When the input voltage of the power supply is greater than 6.1V, the input protection chip turns off its internal transistor to cut off the power input and protect the safety of subsequent chips.

[0044] The inverting charge pump is used to convert the input 5V voltage into a -5V voltage, and provide positive and negative 5V voltages to the discriminator and the reference voltage generator for positive and negative 5V power supply.

[0045] 2. The signal processing module is used to process an external input signal. The signal processing module includes a reference voltage generator, a discriminator connected to the reference voltage generator, an AND gate connected to the discriminator, and a pulse width modulator connected to the AND gate.

[0046] The reference voltage generator primarily consists of an operational amplifier connected to a voltage follower, as well as fixed and adjustable resistors. The generator divides the voltage using a fixed resistor and an adjustable resistor to generate the required reference voltage of approximately -50mV. Adjusting the adjustable resistor's value adjusts the reference voltage. The reference voltage generated by the generator is provided to the discriminator as a threshold for comparison with the external input signal.

[0047] Cosmic ray muons generate scintillation light after passing through a plastic scintillator. This scintillation light is then transmitted to a photomultiplier tube (PMT) or silicon photomultiplier tube (SiPM), whereupon the resulting electrical signal is input into the electronic system via an SMA interface. The discriminator includes an inverting input terminal connected to a reference voltage generator, a positive input terminal connected to a signal input interface, a positive output pin, a complementary output pin, two complementary output channels connected to the AND gate, and an operational amplifier within the discriminator.

[0048] The operational amplifier inside the discriminator chip compares the input signal with the reference voltage and converts it into a TTL signal. When the input signal voltage is lower than the reference voltage, the discriminator outputs a high level, and when the input signal voltage is higher than the reference voltage, the discriminator outputs a low level. The TTL signals of different channels are matched through the AND gate.

[0049] Two complementary output channels are used to use the complementary output pin to output a signal complementary to the positive output pin, that is, when the positive output pin outputs a high level, the complementary output pin outputs a low level, and when the positive output pin outputs a low level, the complementary output pin outputs a high level.

[0050] Connecting the positive output pin of the discriminator to an AND gate can perform coincidence of multiple channel signals, and conversely connecting the complementary output pin of the discriminator to an AND gate can be used for anti-coincidence. The coincident signal is received by the monostable multivibrator chip of the pulse width modulator and the pulse width of the TTL signal is extended to the nanosecond to millisecond level (1.5ms in the application example).

[0051] A pulse width modulator (PWM) consists of a monostable multivibrator connected to an external capacitor and resistor. It receives a transition signal (from high to low or vice versa) and outputs a pulse signal with a given pulse width. The width of the output signal is determined by the time constant τ = RC of the external capacitor and resistor. Therefore, the pulse width of the output signal can be adjusted by the external capacitor and resistor, extending it to nanoseconds or milliseconds. The extended signal is ultimately output through an SMA connector.

[0052] 3. The LED module is used to display the signal processing status. The LED module includes a 5V power indicator light, a -5V power indicator light, and a coincidence detection indicator light connected to the output signal.

[0053] When the external power supply supplies power to the circuit board normally, the 5V power indicator light is on;

[0054] When the reverse charge pump generates a -5V voltage normally, the -5V power indicator light is on;

[0055] The coincidence detection indicator light is used to indicate the signal of cosmic ray muons passing through. When cosmic ray muons continuously pass through two or more plastic scintillators, and the electrical signals of individual PMTs or SiPMs pass through the signal processing module, the signal processing module outputs a 5-microsecond pulse. During the high-level period of the 5-microsecond pulse, the coincidence detection indicator light is on.

[0056] Example 2

[0057] like Figure 2 As shown, the present invention provides a multi-channel coincidence electronics system with adjustable output pulse width, comprising:

[0058] Figure 3 This is an example circuit diagram of the power supply module, such as Figure 3 As shown, an external 5V power supply (VCC) is input through a DC connector and protected by a PW2605 input protection chip before powering the various chips on the board. The 5V power supply is converted to -5V by an LM2776 inverting charge pump to power the discriminator and reference voltage generator. Filter capacitors are placed at the power input pins of each chip to improve stability.

[0059] Figure 4 This is an example circuit diagram of the signal processing module, such as Figure 4 As shown, it consists of a reference voltage generator, a discriminator, an AND gate and a pulse width modulator.

[0060] Figure 5 The example circuit diagram for the reference voltage generation part is as follows: Figure 5 As shown, the LM358 is a two-channel operational amplifier. Its output pin is connected to the inverting input pin to form a voltage follower. The non-inverting input pin is divided down by a resistor R6 and an adjustable resistor R9 to provide a stable reference voltage. The two channels are configured to output a positive reference voltage and a negative reference voltage, respectively. Jumper H1 can be used to select the polarity of the output reference voltage. When the jumper is connected to pins 1 and 2 of H1, a negative voltage is output, and when the jumper is connected to pins 2 and 3 of H1, a positive voltage is output. The magnitude of the reference voltage is determined by the voltage divider between resistor R6 and variable resistor R9 (or resistor R7 and variable resistor R10). The variable resistor can be used to easily adjust the output reference voltage within a certain range.

[0061] Figure 6 The example circuit diagram of the discriminator part is as follows: Figure 6As shown in Figure 1, the AD8561 is a 7ns high-speed comparator that requires a positive or negative 5V power supply. Its inverting input is connected to the reference voltage VREF, while its non-inverting input receives a signal from the SMA connector. The chip has two complementary outputs, 7 and 8, which can be selected using a jumper. This allows the discriminator to output positive or complementary signals, determining whether the channel operates in coincidence or anticoincidence mode. When jumpers H2 1 and 2 are connected, the channel is set to coincidence mode; when jumpers H2 2 and 3 are connected, the channel is set to anticoincidence mode.

[0062] Figure 7 This is an example circuit diagram that conforms to AND gate logic, such as Figure 7 As shown, since there are a total of 4 channels, 3 AND gates are used for the coincidence operation. Pull-up and pull-down resistors are reserved at the input of each AND gate to cope with the possibility that some channels are not used. If a channel is not used, the pull-up resistor of the channel can be soldered to keep the channel at a high level, so that other channels can coincide normally. In this embodiment 2, the SN74LVC1G08 AND gate chip is used.

[0063] Figure 8 The example circuit diagram of the pulse width modulator is as follows: Figure 8 As shown in the figure, CD74HC4538 is a two-channel monostable multivibrator chip. The duration of the output pulse can be adjusted by external resistor C15 and external variable resistor R22. The duration of the signal generated by PMT or SiPM is generally in the nanosecond level. By adjusting the values ​​of external capacitors and resistors, the duration of the output signal can be extended to microseconds or even milliseconds to accommodate different subsequent processing circuits.

[0064] Figure 9 The following is an example circuit diagram of the LED indicator module: Figure 9 As shown, there are three LEDs: one indicating 5V power and one indicating -5V power, used to indicate the normal working status of the circuit. The other is connected to the output signal of the signal processing module through a MOS transistor. When an output signal is generated, the LED will emit a light, indicating that a cosmic ray muon has passed.

[0065] Therefore, the present invention provides a multi-channel electronic system with adjustable output pulse width, which not only simplifies the electronic system and reduces the cost of use, but also can conveniently adjust the pulse width of the output signal, making the present invention highly practical and applicable.

[0066] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0067] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A multi-channel coincident electronics system with adjustable output pulse width, characterized in that: include: A circuit board and a DC input interface, a signal input interface, a signal output interface, a power supply module, a signal processing module, and an LED module provided on the circuit board, wherein the power supply module, the signal processing module, and the LED module are interconnected; The power supply module is used to connect an external power source to power the various chips on the circuit board. The power supply module includes an external 5V power adapter, an input protection chip connected to the 5V power adapter, and a reverse charge pump connected to the input protection chip; The signal processing module is used to process an external input signal, and the signal processing module includes a reference voltage generator, a discriminator connected to the reference voltage generator, an AND gate connected to the discriminator, and a pulse width modulator connected to the AND gate; The LED module is used to display the signal processing status, and the LED module includes a 5V power indicator light, a -5V power indicator light, and a coincidence detection indicator light connected to the output signal; The reference voltage generator is composed of an operational amplifier, a fixed resistor, and an adjustable resistor. The reference voltage generator is used to divide the voltage by the fixed resistor and the adjustable resistor to obtain a reference voltage, and the reference voltage is provided to the discriminator as a threshold for comparing the external input signal. The value of the reference voltage can be adjusted by the adjustable resistor, and the reference voltage is -50mV. The discriminator includes an inverting input terminal connected to the reference voltage generator, a non-inverting input terminal connected to the signal input interface, a positive output pin, a complementary output pin, two complementary output channels connected to the AND gate, and an operational amplifier arranged inside the discriminator; In the discriminator: The inverting input terminal of the discriminator is connected to the reference voltage VREF, and the non-inverting input terminal receives the signal input from the signal access interface; The discriminator has two complementary outputs. The output signal is selected by the jumper. By adjusting the jumper, the discriminator outputs positive signal or complementary signal to determine whether the channel is in coincidence or anti-coincidence. The operational amplifier is used to compare the reference voltage and the input signal voltage and convert the input signal into a TTL signal. When the input signal voltage is lower than the reference voltage, the positive output pin of the discriminator outputs a high level. When the input signal voltage is higher than the reference voltage, the positive output pin of the discriminator outputs a low level. The TTL signals of different channels are matched through an AND gate. The complementary output channel is used to output a signal complementary to the positive output pin using the complementary output pin, and when the positive output pin outputs a high level, the complementary output pin outputs a low level, and when the positive output pin outputs a low level, the complementary output pin outputs a high level; The AND gate is used to perform signal matching. When the AND gate is connected to the positive output pin, it matches the signals of multiple channels. When the AND gate is connected to the complementary output pin, it performs anti-matching and transmits the matched TTL signal to the pulse width modulator. The pulse width modulator is composed of a monostable multivibrator and is externally connected to a capacitor and a resistor. The pulse width modulator is used to use the monostable multivibrator to receive a matched TTL signal, and use the time constant τ=RC of the external capacitor and the external resistor to extend the pulse width of the matched TTL signal to the nanosecond to millisecond level. The signal with the extended width is output through the signal output interface.

2. The multi-channel coincidence electronics system with adjustable output pulse width according to claim 1, characterized in that: The 5V power adapter is used to connect to the DC input interface and, after being protected by the input protection chip, to power each chip on the circuit board; The input protection chip is used to protect the chip safety. When the input voltage of the power supply is greater than 6.1V, the input protection chip turns off its internal transistor to cut off the power input; The inverting charge pump is used to convert the input 5V voltage into a -5V voltage, and provide positive and negative 5V voltages to the discriminator and the reference voltage generator for positive and negative 5V power supply.

3. The multi-channel coincidence electronics system with adjustable output pulse width according to claim 1, characterized in that: The 5V power indicator light is used to light up when the external power supply is normally supplying power to the circuit board; The -5V power indicator light is used to light up when the reverse charge pump normally generates a -5V voltage; The coincidence detection indicator light is used to indicate the signal of the passage of cosmic ray muons. When a cosmic ray muon passes through the signal processing module, the signal processing module outputs a pulse with a length of 5 microseconds. During the high level period of the 5 microsecond pulse, the coincidence detection indicator light is on.

4. The multi-channel coincidence electronics system with adjustable output pulse width according to claim 3, characterized in that: The input pins of the power supply of each chip on the circuit board are all provided with filter capacitors to improve stability.

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