Virtual load of constant current driver of flow cytometer

Abstract

The utility model belongs to the technical field of instrument debugging, and particularly relates to a virtual load of a flow cytometer constant current driver, which is characterized by comprising a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R6, a capacitor C1, a capacitor C2, a power supply V1, a power supply V3, an amplifier U3, a field effect transistor M1, a transistor Q1 and a diode D1. The virtual load of the constant current driver of the flow cytometer provided by the utility model is a circuit device capable of accurately adjusting the voltage drop (1-10V) of the virtual load of a laser within 4A constant current so as to simulate different lasers to meet design requirements, and the risk of damaging the laser in the debugging process of the constant current driver of the laser is greatly reduced; and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of instrument debugging, particularly to the virtual load of flow cytometer constant current driver. BACKGROUND

[0002] Flow cytometry (F l ow cytometry) generally includes: optical system, liquid flow system, detection and data processing system, and some flow cytometers also include cell sorting system, is a kind of high-tech biomedical detection instrument that can quickly, accurately, objectively and simultaneously detect multiple physical and biological characteristics of single cell, and is widely used in the research and quantitative research of biological cell characteristics.

[0003] In recent years, due to the low cost of flow cytometer, self-developed laser constant current driver, temperature controller and the like have become a trend.

[0004] However, the laser is a fragile and expensive device, and once damaged, it cannot be repaired. Therefore, during research and development, laser virtual load is generally used first, and real laser is not used until the circuit board is debugged without problem, so as to reduce the risk of damage.

[0005] The traditional laser constant current driver virtual load is generally obtained by connecting diodes in series. By connecting diodes in series, a voltage drop close to the forward voltage of the laser can be obtained. Figure 1 However, the problem is that the diode tolerance is large, and the precision will be affected due to temperature and current changes. When the compliance voltage and other parameters of the constant current source driver need to be verified, the current virtual load cannot meet the requirements.

[0006] Therefore, the utility model provides a virtual load of flow cytometer constant current driver. Utility model content

[0007] The utility model provides a kind of virtual load of flow cytometer constant current driver, to provide a kind of in 4A constant current, can accurately adjust laser virtual load voltage drop (1 ~ 10V) circuit device, to simulate different lasers.

[0008] The utility model provides a kind of virtual load of flow cytometer constant current driver, including: resistance R1, resistance R2, resistance R3, resistance R4, resistance R6, electric capacity C1, electric capacity C2, power supply V1, power supply V3, amplifier U3, field effect tube M1, transistor Q1, diode D1;

[0009] The positive stage of the power supply V1 is connected with the power supply end of the amplifier U3, the positive stage of the power supply V3 is connected with one end of the resistor R6, the other end of the resistor R6 is connected with one end of the capacitor C1 and the negative end of the amplifier U3 respectively, the other end of the capacitor C1 is connected with the output end of the amplifier U3 and one end of the capacitor R1 respectively, the other end of the capacitor R1 is connected with one end of the capacitor C2 and one end of the field effect tube M1 respectively, the other end of the capacitor C2 is connected with one end of the resistor R3 and the other end of the field effect tube M1 respectively, the other end of the amplifier U3 is connected with one end of the resistor R2, the other end of the resistor R3 is connected with the other end of the resistor R2, one end of the transistor Q1 and one end of the diode D1 respectively, the other end of the transistor Q1 is connected with one end of the resistor R4, and the other end of the resistor R4 is connected with the other end of the field effect tube M1.

[0010] The ground ends of the power supply V1, the power supply V3, the amplifier U3, the field effect tube M1, the transistor Q1 and the diode D1 are connected with the ground GND respectively.

[0011] The virtual load of the constant current driver of the flow cytometer provided by the utility model further comprises a constant current source.

[0012] The constant current source comprises a resistor R5 and a power supply V2.

[0013] When the laser cathode is grounded, the resistor R5 is connected with the negative pole of the diode D1, one end of the resistor R2, one end of the resistor R3 and one end of the transistor Q1 respectively.

[0014] When the laser is in a floating state, the virtual load of the constant current driver of the flow cytometer further comprises a resistor R7.

[0015] The resistor R7 is connected with the negative pole of the diode D1, one end of the resistor R2, one end of the resistor R3 and one end of the transistor Q1 respectively.

[0016] One end of the resistor R5 is connected with the positive pole of the diode D1, one end of the transistor Q1 and one end of the field effect tube respectively.

[0017] The other end of the resistor R5 is grounded.

[0018] The power supply V3 adopts a sliding resistor to realize voltage division.

[0019] Compared with the closest prior art, the utility model has the beneficial effects that:

[0020] The virtual load of the flow cytometer constant current driver provided by the utility model can precisely adjust the circuit device of laser virtual load voltage drop (1-10V) within 4A constant current, simulate different lasers to meet design requirements, and solve the problems of low precision and inability to meet requirements in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0022] Figure 1 The circuit diagram of the virtual load of the traditional laser constant current driver in the embodiment of the utility model;

[0023] Figure 2 The implementation circuit diagram of the virtual load in the embodiment of the utility model;

[0024] Figure 3 The constant current source circuit for driving the anode ground connection laser in the embodiment of the utility model;

[0025] Figure 4 The constant current source circuit for driving the cathode ground connection laser in the embodiment of the utility model;

[0026] Figure 5 The constant current source circuit for driving the floating connection laser in the embodiment of the utility model;

[0027] Figure 6 The setting voltage value and the voltage drop diagram after the actual access to the constant current source circuit of the laser virtual load in the embodiment of the utility model. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiment of the utility model clearer, the technical scheme in the embodiment of the utility model will be described clearly and completely in combination with the drawings in the embodiment of the utility model. Obviously, the described embodiments are some embodiments of the utility model, not all the embodiments. The components of the embodiment of the utility model described and shown in the drawings can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0030] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for differentiation, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the embodiments of the present application, it should be noted that the orientation or position relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship commonly used when the product of the present application is used, which is only for the convenience of describing the present application and simplifying the description, and cannot be understood as indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0032] The utility model provides a kind of virtual load of flow cytometer constant current driver, as shown in Figure 2 Resistance R1, resistance R2, resistance R3, resistance R4, resistance R6, capacitor C1, capacitor C2, power supply V1, power supply V3, amplifier U3, field effect tube M1, transistor Q1, diode D1 are included.

[0033] Among them, the positive stage of power supply V1 is connected with the power supply end of amplifier U3, the positive stage of power supply V3 is connected with one end of resistance R6, the other end of resistance R6 is connected with one end of capacitor C1 and the negative end of amplifier U3 respectively, the other end of capacitor C1 is connected with the output end of amplifier U3 and one end of capacitor R1 respectively, the other end of capacitor R1 is connected with one end of capacitor C2 and one end of field effect tube M1 respectively, the other end of capacitor C2 is connected with one end of resistance R3 and the other end of field effect tube M1 respectively, the other end of amplifier U3 is connected with one end of resistance R2, the other end of resistance R3 is connected with the other end of resistance R2, one end of transistor Q1 and one end of diode D1 respectively, the other end of transistor Q1 is connected with one end of resistance R4, and the other end of resistance R4 is connected with the other end of field effect tube M1.

[0034] The ground terminals of power supply V1, power supply V3, amplifier U3, field effect tube M1, transistor Q1 and diode D1 are connected with ground GND respectively.

[0035] Preferably, it further includes a constant current source.

[0036] The constant current source includes: resistor R5 and power supply V2.

[0037] Preferably, when the laser cathode is grounded, the resistor R5 is connected to the negative terminal of the diode D1, one end of the resistor R2, one end of the resistor R3, and one end of the transistor Q1.

[0038] Preferably, when the laser anode is grounded, the resistor R5 is connected to the positive terminal of diode D1, one end of transistor Q1, and one end of field-effect transistor, respectively.

[0039] Preferably, when the laser is in a floating state, it also includes resistor R7.

[0040] Preferably, the resistor R7 is connected to the negative terminal of the diode D1, one end of the resistor R2, one end of the resistor R3, and one end of the transistor Q1, respectively.

[0041] One end of the resistor R5 is connected to the positive terminal of the diode D1, one end of the transistor Q1, and one end of the field-effect transistor, respectively.

[0042] The other end of the resistor R5 is grounded.

[0043] Preferably, the power supply V3 uses a sliding rheostat to achieve voltage division.

[0044] In this embodiment, such as Figure 2 As shown, connect OUT+ to the positive output terminal of the constant current source and GND to the negative output terminal of the constant current source. If a virtual floating load is required, then battery power can be used. Our U3 power supply is 15V, so simulating a laser forward conduction voltage of 0.5~10V is perfectly fine, which basically covers most lasers on the market.

[0045] Its working principle mainly utilizes the "virtual short" characteristic of operational amplifier circuits during negative feedback. Therefore, it's crucial to first confirm whether the circuit is experiencing negative feedback. Entering the circuit from any point in the loop will determine if it's negative feedback. Here, we inject a positive change into the non-inverting input of U3, resulting in a positive change in the output of U3. The voltage at the junction of M1 and R3 will decrease; this voltage also drives the base of Q1, so the voltage at the OUT+ junction will also decrease. OUT+ is connected back to the non-inverting input of U3 through R2. Due to the virtual short characteristic of the operational amplifier, there is almost no voltage drop across R2. At this point, we can determine that this loop is a negative feedback loop: a positive change input to U3 results in a negative change output.

[0046] V3 is an adjustable voltage source. In actual circuits, a sliding rheostat can be used as a voltage divider circuit to achieve precise adjustment of the forward conduction voltage of the laser's simulated load.

[0047] In this embodiment, in order to facilitate debugging, a constant current source driving circuit compatible with any laser connection type is provided. Figure 3 For the constant current source circuit driving the anode-ground connected laser, it can be connected according to Figure 4 For the constant current source circuit driving the cathode-ground connected laser, it can be connected according to Figure 5 For the constant current source circuit driving the floating connected laser, it can be connected according to

[0048] In this embodiment, the two-terminal voltage drop is adjusted to simulate various forward conduction voltage lasers: within 4A constant current, the laser with 1-10V forward conduction voltage drop can be accurately simulated, and the operation is simple, which greatly reduces the risk of damaging the laser in the laser constant current source driver debugging process, such as Figure 6 As shown, the setting voltage value of the laser virtual load is not affected by the factors such as current temperature and the like, and the coincidence degree of the two curves is as high as 99.9%, which can well solve the problem of precision caused by temperature and current change in the prior art.

[0049] The beneficial effects of the above technical solutions are: a circuit device capable of accurately adjusting the voltage drop (1-10V) of the laser virtual load within 4A constant current is provided to simulate different lasers to meet the design requirements, and the risk of damaging the laser in the laser constant current source driver debugging process is greatly reduced, and the cost is reduced.

[0050] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A virtual load for a constant current driver of a flow cytometer, characterized by, Comprise: Resistance R1, resistance R2, resistance R3, resistance R4, resistance R6, capacitor C1, capacitor C2, power supply V1, power supply V3, amplifier U3, field effect transistor M1, transistor Q1, diode D1; Among them, the positive stage of power supply V1 is connected with the power supply end of amplifier U3, the positive stage of power supply V3 is connected with one end of resistance R6, the other end of resistance R6 is connected with one end of capacitor C1 and the negative end of amplifier U3 respectively, the other end of capacitor C1 is connected with the output end of amplifier U3 and one end of capacitor R1 respectively, the other end of capacitor R1 is connected with one end of capacitor C2 and one end of field effect transistor M1 respectively, the other end of capacitor C2 is connected with one end of resistance R3 and the other end of field effect transistor M1 respectively, the other end of amplifier U3 is connected with one end of resistance R2, the other end of resistance R3 is connected with the other end of resistance R2, one end of transistor Q1 and one end of diode D1 respectively, the other end of transistor Q1 is connected with one end of resistance R4, and the other end of resistance R4 is connected with the other end of field effect transistor M1; The ground ends of power supply V1, power supply V3, amplifier U3, field effect transistor M1, transistor Q1 and diode D1 are connected with ground GND respectively.

2. The virtual load for a constant current driver for a flow cytometer of claim 1, wherein, Also comprise: Constant current source; The constant current source comprises resistance R5 and power supply V2.

3. The virtual load of the constant current driver of the flow cytometer according to claim 2, wherein, When the laser cathode is grounded, the resistance R5 is connected with the negative electrode of diode D1, one end of resistance R2, one end of resistance R3 and one end of transistor Q1 respectively.

4. The virtual load of the constant current driver of the flow cytometer according to claim 2, wherein, When the laser anode is grounded, the resistance R5 is connected with the positive electrode of diode D1, one end of transistor Q1 and one end of field effect transistor respectively.

5. The virtual load of the constant current driver of the flow cytometer according to claim 2, wherein, When the laser is in floating state, it further comprises resistance R7.

6. The virtual load of the constant current driver of the flow cytometer according to claim 5, wherein, The resistance R7 is connected with the negative electrode of diode D1, one end of resistance R2, one end of resistance R3 and one end of transistor Q1 respectively; One end of the resistance R5 is connected with the positive electrode of diode D1, one end of transistor Q1 and one end of field effect transistor respectively; The other end of the resistance R5 is grounded.

7. The virtual load for a constant current driver of a flow cytometer according to any of claims 1-6, wherein, The power supply V3 adopts a slide rheostat to realize voltage division.

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