Accelerator pedal analog quantity protection output circuit

Abstract

The utility model provides an accelerator pedal analog quantity with protection output circuit, comprising an operational amplifier U1, a first input end of which is connected to an analog quantity input end AIN1 through a resistor R2; one end of the resistor R1 is grounded, and the other end of the resistor R1 is connected to the second input end of the operational amplifier U1; the output end of the operational amplifier U1 is connected to the analog quantity output end ADC1 sequentially through a diode D2 and a resistor R4 which are connected in series, and the conduction direction of the diode D2 is that the diode D2 is conducted from the diode D2 to the resistor R4 and is reversely cut off from the resistor R4 to the diode D2; and one end of the resistor R3 is connected to the second input end of the operational amplifier U1 and is connected with the power supply positive electrode + VCC, and the other end of the resistor R3 is connected to the analog quantity output end ADC1. The scheme has the characteristics of high circuit universality, low cost and high reliability.

Description

Technical Field

[0001] This utility model relates to the field of electric forklift technology, and in particular to an analog output circuit for accelerator pedal with protection. Background Technology

[0002] The analog signal output by the accelerator pedal is usually a resistor or an internal Hall effect analog signal. Shorting this analog output signal to the negative or positive terminal of the power supply will damage the analog output signal of the accelerator pedal. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide an analog output circuit for accelerator pedal with protection. This circuit uses resistors, diodes, and operational amplifiers to form an analog signal amplification and protection circuit, which features strong circuit versatility, low cost, and high reliability.

[0004] An analog accelerator pedal output circuit with protection includes:

[0005] Operational amplifier U1, the first input terminal of operational amplifier U1 is connected to analog input terminal AIN1 through resistor R2;

[0006] Resistor R1 has one end grounded and the other end connected to the second input terminal of the operational amplifier U1;

[0007] The output terminal of the operational amplifier U1 is connected to the analog output terminal ADC1 through a series diode D2 and a resistor R4. The conduction direction of the diode D2 is from diode D2 to resistor R4, and the reverse direction is cut off from resistor R4 to diode D2.

[0008] Resistor R3 is connected at one end to the second input terminal of the operational amplifier U1 and to the positive power supply +VCC, and at the other end to the analog output terminal ADC1.

[0009] Preferably, a diode D1 is also included. One end of the diode D1 is connected to the second input terminal of the operational amplifier U1, and the other end of the diode D1 is connected to the positive power supply +VCC. The conduction direction of the diode D1 is from the resistor R3 to the diode D1 and from the diode D1 to the resistor R3.

[0010] In the above scheme, the AIN1 input signal is input to the input terminal of operational amplifier U1 via resistor R2. The input terminal of operational amplifier U1 then passes through an amplifier circuit composed of resistors R1, R3, R4, and diode D2 to output the ADC1 signal. When the ADC1 signal is short-circuited to the negative terminal of the power supply, the current limitation by resistor R4 prevents excessive current from damaging operational amplifier U1 and the input signal AN1. When the ADC1 signal is short-circuited to the positive terminal of the power supply, the excessively high positive voltage flows through diode D1 to +VCC through resistor R3. The voltage at the input terminal of the operational amplifier is clamped by diode D1, preventing overvoltage of the operational amplifier. Simultaneously, the excessively high positive voltage is reverse-biased by diode D2, preventing current from flowing into the output terminal of the operational amplifier. This achieves protection for operational amplifier U1 and the input signal AN1. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this application. Detailed Implementation

[0012] The embodiments of this utility model are described in detail below.

[0013] like Figure 1 As shown, this embodiment provides an analog output circuit for an accelerator pedal with protection, including an operational amplifier U1, resistors R1 and R2,

[0014] R3, R4, and diodes D1 and D2. The analog input terminal AIN1 is connected to resistor R2, which is connected to the input terminal of operational amplifier U1. The other input terminal of operational amplifier U1 is connected to resistor R1 and then to resistor R3. Resistor R3 is connected to resistor R4, which outputs to ADC1. The other end of resistor R4 is connected to diode D2, which is connected to the output terminal of operational amplifier U1.

[0015] In this circuit, when the analog output terminal (ADC1) is short-circuited to the negative terminal of the power supply, the resistor R4 connected in series at the output terminal significantly reduces the short-circuit current by limiting the current, preventing the operational amplifier U1 and the input signal terminal AIN1 from burning out due to overcurrent. When ADC1 is short-circuited to the positive terminal of the power supply, the high voltage at the positive terminal flows to diode D1 through resistor R3. The forward voltage drop of D1 clamps the voltage at the input terminal of operational amplifier U1 within a safe range, preventing damage from overvoltage at the input terminal. The anode of D2 is connected to ADC1, and the cathode is connected to the output terminal of U1. When the voltage of ADC1 is higher than the voltage at the output terminal of U1, D2 is reverse-biased, preventing current from flowing back from the positive terminal of the power supply to the output terminal of U1, thus protecting the output stage of the operational amplifier. Therefore, in the above circuit, the reverse-biased characteristics of diodes D1 and D2 can achieve short-circuit protection, and together with other circuit components, solve the problem that the traditional accelerator pedal output signal is easily damaged by short circuits.

[0016] Specifically, the AIN1 input signal is input to the input terminal of operational amplifier U1 via resistor R2. The input terminal of operational amplifier U1 then passes through an amplifier circuit composed of resistors R1, R3, R4, and diode D2 to output the ADC1 signal. When the ADC1 signal is short-circuited to the negative terminal of the power supply, the current limiting effect of resistor R4 prevents excessive current from damaging operational amplifier U1 and the input signal AN1. When the ADC1 signal is short-circuited to the positive terminal of the power supply, the excessively high positive voltage flows through diode D1 to +VCC via resistor R3. The voltage at the input terminal of the operational amplifier is clamped by diode D1, preventing overvoltage. Simultaneously, the excessively high positive voltage is reverse-biased by diode D2, preventing current from flowing into the output terminal of the operational amplifier. This effectively protects operational amplifier U1 and the input signal AN1.

[0017] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A circuit for analog output of accelerator pedal with protection, characterized in that, include: Operational amplifier U1, the first input terminal of operational amplifier U1 is connected to analog input terminal AIN1 through resistor R2; Resistor R1 has one end grounded and the other end connected to the second input terminal of the operational amplifier U1; The output terminal of the operational amplifier U1 is connected to the analog output terminal ADC1 through a series diode D2 and a resistor R4. The conduction direction of the diode D2 is from diode D2 to resistor R4, and the reverse direction is cut off from resistor R4 to diode D2. Resistor R3 is connected at one end to the second input terminal of the operational amplifier U1 and to the positive power supply +VCC, and at the other end to the analog output terminal ADC1.

2. The accelerator pedal analog output circuit with protection according to claim 1, characterized in that, It also includes a diode D1, one end of which is connected to the second input terminal of the operational amplifier U1, and the other end of which is connected to the positive power supply +VCC; the conduction direction of the diode D1 is from the resistor R3 to the diode D1 and from the diode D1 to the resistor R3.

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