Digital adjustable battery discharge load circuit

Abstract

The utility model relates to a digital adjustable battery discharge load circuit, which comprises a main control chip, N discharge resistors and n relays, the n relays are connected in series with a detection battery, the discharge resistors are connected with the relays, the resistance value of the Nth discharge resistor is 2N, the main control chip is connected with the input end of the relay, and the main control chip is connected with the output end of the relay. The main control chip carries out binary decoding on a specified resistance value, when the main control chip transmits a signal 1 to the relay, the discharge resistor is connected to the circuit, and when the main control chip transmits a signal 0 to the relay, the relay connects the wire to the circuit. By controlling the number of resistors connected to the circuit, more different test resistance values can be obtained, the discharge effects of different loads can be simulated, and the test result is more accurate.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and in particular to a digitally adjustable battery discharge load circuit. Background Technology

[0002] Currently, battery discharge testing primarily uses a fixed discharge resistor in conjunction with the switching of an NMOS transistor. The discharge current is adjusted by changing the duty cycle of the PWM signal controlling the NMOS transistor's switching, thus simulating the discharge effect under different loads. However, this method has two drawbacks: firstly, the discharge current accuracy is low, and it still differs from the actual discharge effect under real loads, resulting in unreliable measurement results; secondly, the battery is constantly switching between discharging and non-discharging, which significantly impacts battery lifespan. Summary of the Invention

[0003] This invention provides a digitally adjustable battery discharge load circuit, aiming to solve the problem of low measurement accuracy in existing battery testing methods.

[0004] This invention provides a digitally adjustable battery discharge load circuit, including a main control chip, N discharge resistors, and n relays. The n relays are connected in series with the detected battery, and the discharge resistors are connected to the relays. The resistance of the Nth discharge resistor is 2. N The main control chip is connected to the input terminal of the relay. The main control chip performs binary decoding on the specified resistance value. When the main control chip transmits signal 1 to the relay, the discharge resistor is connected to the circuit. When the main control chip transmits signal 0 to the relay, the relay connects the wire to the circuit.

[0005] As a further improvement of this utility model, pin 7 of the relay is connected to one end of the discharge resistor, and pin 8 of the relay is connected to the other end of the discharge resistor.

[0006] As a further improvement of this utility model, pin 5 of the relay is connected to pin 1 of the detection battery, and pin 6 of the relay is connected to pin 2 of the detection battery.

[0007] As a further improvement to this utility model, transistor Q n The collector of the transistor is connected to pins 1 and 2 of the relay, and the transistor Q... n The emitter is grounded, and the transistor Q... n The base of the electrode is connected to the main control chip.

[0008] As a further improvement to this utility model, transistor Q n collector and diode Dn The positive terminal of diode D is connected. n The negative terminal is connected to pin 2 of the relay.

[0009] As a further improvement of this utility model, it also includes a Type-C female connector and a voltage conversion chip. The Type-C female connector is connected to an external power supply and outputs a 5V voltage to pin 3 of the voltage conversion chip. Pin 2 of the voltage conversion chip outputs a 3.3V voltage to pin 9 of the main control chip.

[0010] As a further improvement of this utility model, pin 2 of the relay is connected to a 5V voltage.

[0011] As a further improvement of this utility model, the main control chip is model STC8G1K08.

[0012] The beneficial effects of this invention are: by controlling the number of resistors in the circuit, more different test resistance values ​​can be obtained, simulating the discharge effect of different loads, and the test results are more accurate. Attached Figure Description

[0013] Figure 1 This is a detailed connection diagram of the circuit of this utility model. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0015] like Figure 1 As shown, this utility model provides a digitally adjustable battery discharge load circuit, including a main control chip, N discharge resistors and n relays. The n relays are connected in series with the detection battery, and the discharge resistors are connected to the relays. The resistance of the Nth discharge resistor is 2. N The main control chip is connected to the input terminal of the relay. The main control chip performs binary decoding on the specified resistance value. When the main control chip transmits signal 1 to the relay, the discharge resistor is connected to the circuit. When the main control chip transmits signal 0 to the relay, the relay connects the wire to the circuit.

[0016] This solution uses the principle of decimal to binary conversion. First, the main control chip performs binary decoding on the specified resistance value. That is, any resistance value X can be converted into X = 1*a+2*b+4*c+8*d……, where a, b, c, d… are only 0 or 1, and 1, 2, 4, 8 in the formula are the resistance values ​​of each resistor.

[0017] In this circuit, N discharge resistors are selected and connected in series, depending on the situation. The resistance values ​​of the discharge resistors increase exponentially in binary, where N is a natural number starting from 0. That is, the first discharge resistor has a resistance of 1 ohm, the second 2 ohms, the third 4 ohms, the fourth 8 ohms, and so on. Each discharge resistor is connected to the circuit in conjunction with a relay. The control chip controls the switching of the relays to determine whether a pure wire or a resistor is connected to the circuit. For the values ​​of a, b, c, d... above, when the signal output by the main control chip to the relay is 1, a discharge resistor is connected; when it is 0, a wire is connected. This ensures that the total resistance in the circuit is a specified value X. When the value of X needs to change, the main control chip can recalculate and dynamically adjust the corresponding relays, thereby changing the number of discharge resistors connected to the detection circuit and obtaining different detection resistance values.

[0018] The number of relays and discharge resistors is the same, where n is a natural number starting from 1. The more relays and discharge resistors connected, the more resistance values ​​can be tested, the more test results can be obtained, and the more accurate the conclusions will be.

[0019] In another embodiment of this utility model, pin 7 of the relay is connected to one end of the discharge resistor, and pin 8 of the relay is connected to the other end of the discharge resistor; pin 5 of the relay is connected to pin 1 of the detection battery, and pin 6 of the relay is connected to pin 2 of the detection battery. Through the signal transmitted by the main control chip, the relay can control whether to connect to the discharge resistor or to a wire. In this embodiment of the utility model, the relay is a double-pole double-throw relay, and the relay model is SMIH_05VDC.

[0020] As another embodiment of this utility model, transistor Q n The collector of the transistor is connected to pins 1 and 2 of the relay, and the transistor Q... n The emitter is grounded, and the transistor Q... n The base of the transistor is connected to the main control chip; transistor Q n collector and diode D n The positive terminal of diode D is connected. n The negative terminal is connected to pin 2 of the relay; pin 2 of the relay is supplied with a 5V voltage. The relay is powered by a 5V voltage, wherein transistor Q... n Transistor Q is used to receive signals from the main control chip for the relay. n The number is determined by the number of relays, diode D n The number is also determined by the number of relays.

[0021] In another embodiment of this utility model, a Type-C female connector and a voltage conversion chip are also included. The Type-C female connector is connected to an external power supply and outputs 5V voltage to pin 3 of the voltage conversion chip. Pin 2 of the voltage conversion chip outputs 3.3V voltage to pin 9 of the main control chip. The Type-C female connector ( Figure 1 J1 in the circuit serves as the power interface, outputting a 5V voltage to power the relay, and the voltage is converted by the voltage conversion chip (J1). Figure 1 The chip U5 in the main control chip converts the 5V voltage to 3.3V to power the main control chip. In this embodiment of the invention, the voltage conversion chip is model ME6216A33XG_6uA.

[0022] The main control chip ( Figure 1 The chip U4 in the middle is model STC8G1K08. The main control chip has multiple I / O pins and is used in conjunction with multiple relays.

[0023] The testing method is as follows: the main control chip obtains the current resistance value X to be set; X is converted into a binary expression by repeatedly dividing by 2 and taking the remainder; the coefficients before each binary number are used to control each relay by connecting a wire with 0 and a resistor with 1; after the relays are operated, the resistance value connected in series will be exactly X, and the specified battery discharge test can be performed; when the total resistance value X changes, the above operation is repeated.

[0024] The more discharge resistors connected in series, the more combined resistance values ​​can be obtained exponentially, enabling high-precision discharge testing of the battery. For example, selecting three resistors—1 ohm, 2 ohm, and 4 ohm—resistances distributed in a binary pattern, and connecting them in series via a relay, allows for precise control of the relay's connection and bypass via a main control chip. This yields eight possible total resistance values: 0, 1, 2, 3, 4, 5, 6, and 7. Adding more binary-valued resistors allows for the creation of even more natural-number resistance values. Furthermore, since the discharge current is adjusted by changing the resistance values, it has no impact on battery life and better reflects actual battery usage scenarios.

[0025] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A digitally adjustable battery discharge load circuit, characterized in that, Including master control chip, n discharge resistance and n relay, n said relay with the detection battery in series, the discharge resistance and the relay are connected, the resistance value of the nth discharge resistance is 2 N , the master control chip is connected with the input end of the relay, the master control chip carries out binary decoding to the specified resistance value, when the master control chip transmits signal 1 to the relay, the discharge resistance is connected to the circuit, when the master control chip transmits signal 0 to the relay, the relay connects the wire to the circuit.

2. The digitally adjustable battery discharge load circuit of claim 1, wherein, The 7th pin of the relay is connected with one end of the discharge resistance, and the 8th pin of the relay is connected with the other end of the discharge resistance.

3. The digitally adjustable battery discharge load circuit of claim 1, wherein, The 5th pin of the relay is connected with the 1st pin of the detection battery, and the 6th pin of the relay is connected with the 2nd pin of the detection battery.

4. The digitally adjustable battery discharge load circuit of claim 1, wherein, The collector of the transistor Q n is connected with the 1, 2 pins of the relay, the emitter of the transistor Q n is grounded, and the base of the transistor Q n is connected with the master chip.

5. The digitally adjustable battery discharge load circuit of claim 4, wherein, The collector of the transistor Q n is connected to the anode of the diode D n The cathode of the diode D n is connected to the 2 pin of the relay.

6. The digitally adjustable battery discharge load circuit of claim 1, wherein, A TypeC female seat and a voltage conversion chip are further included, the TypeC female seat is connected with an external power supply, outputs a 5V voltage to the 3rd pin of the voltage conversion chip, and the 2nd pin of the voltage conversion chip outputs a 3.3V voltage to the 9th pin of the main control chip.

7. The digitally adjustable battery discharge load circuit of claim 6, wherein, The 2nd pin of the relay is connected with a 5V voltage.

8. The digitally adjustable battery discharge load circuit of claim 1, wherein, The model of the main control chip adopts STC8G1K08.

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