Novel electric heating device based on single-chip microcomputer control

Abstract

The electric heating device overcomes the defects that an existing electric heating device cannot automatically adjust output power, cannot provide enough power for heating passengers when a main power supply of the electric heating device is lower than a nominal value, and is prone to overtemperature protection and even damage when the main power supply of the electric heating device is higher than the nominal value. And the reliability and the safety of the electric heating device are improved.

Description

Technical Field

[0001] The utility model relates to a novel electric heating device used in rail transit vehicles, which is a novel electric heating device based on single chip microcomputer control. Background Art

[0002] The electric heating devices used on existing rail transit vehicles directly connect the power supply to the positive and negative terminals of the heating elements in the electric heating devices, and are unable to automatically adjust the output power of the electric heater. When the main power supply of the electric heating device is lower than the nominal value, it cannot provide sufficient power for heating passengers; when the main power supply of the electric heating device is higher than the nominal value, the electric heating device is prone to over-temperature protection or even damage. Utility Model Content

[0003] The utility model overcomes the shortcomings of the existing electric heating device that cannot automatically adjust the output power, cannot provide sufficient power for heating passengers when the main power supply of the electric heating device is lower than the nominal value, and is prone to over-temperature protection or even damage when the main power supply of the electric heating device is higher than the nominal value, thereby improving the reliability and safety of the electric heating device.

[0004] The technical solution of the utility model is: using an LM324 operational amplifier and a TBC25SYH current sensor to process the power supply voltage signal of the electric heating device and the working current signal of the heating element into signals that can be recognized by the single-chip microcomputer and sent to the single-chip microcomputer; the single-chip microcomputer outputs a PWM signal according to the detected voltage and current signals to control the output current of the heating element through the TLP521-1 optocoupler and the FQL40N50 field-effect transistor; the beneficial effect of the utility model is that the electric heating device can automatically adjust the output power when the power supply voltage is too low or too high, so that the electric heating device can always operate at the rated power, reducing the risk of over-temperature protection or even damage to the heating element. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present invention will be further described below with reference to the accompanying drawings.

[0006] Figure 1 It is an electrical principle diagram of the present utility model.

[0007] In the figure: LM324 operational amplifier 1, TLP521-1 optocoupler 2, TLP521-1 optocoupler 3, FQL40N50 field effect transistor 4, TBC25SYH current sensor 5, electric heating device heating element 6, STC12C5410AD microcontroller 7. DETAILED DESCRIPTION

[0008] The following is combined with Figure 1 The utility model is described in further detail:

[0009] A new type of electric heating device based on single chip microcomputer control, see Figure 1 ,The device is composed of a working instruction part, a signal acquisition part, a signal processing part, a PWM signal output control part, and a heating part;

[0010] The working instruction part is composed of TLP521-1 optocoupler 2;

[0011] The signal acquisition part is composed of LM324 operational amplifier 1 and TBC25SYH current sensor 5;

[0012] The signal processing part is composed of STC12C5410AD single chip microcomputer 7;

[0013] The PWM signal output control part is composed of a TLP521-1 optocoupler 3 and a FQL40N50 field effect transistor 4;

[0014] The heating part is composed of the heating element 6 of the electric heating device;

[0015] The specific working principle of the device is as follows: the power supply voltage signal of the electric heating device is converted into a higher voltage signal (500-660VDC) through the LM324 operational amplifier 1 into a 0-5V analog voltage that can be recognized by the single chip microcomputer and sent to the 18th pin of the STC12C5410AD single chip microcomputer 7;

[0016] The TBC25SYH current sensor processes the working current signal of the heating element into a 0-5V analog voltage signal that can be recognized by the microcontroller and sends it to the 19th pin of the microcontroller;

[0017] After turning on the panel control switch, the light-emitting side of the TLP521-1 optocoupler 2 is turned on. After the output end is turned on, the first pin of the STC12C5410AD microcontroller 7 is converted from a high level to a low level. After the STC12C5410AD microcontroller 7 receives the working instruction of the electric heating device, it calculates the product of the two values ​​​​according to the detected power supply voltage signal and working current signal through the internal software of the STC12C5410AD microcontroller 7 and compares it with the set power. A PWM signal with a pulse width that can be changed in real time is output through the 7th pin of the STC12C5410AD microcontroller. This signal is isolated by the TLP521-1 optocoupler 3 and controls the conduction and shutdown of the FQL40N50 field effect tube 4, so that the power of the electric heating device is always maintained at the set power when the power supply voltage fluctuates unstablely.

Claims

1. A novel electric heating device based on single-chip microcomputer control, the device consists of a working instruction part, a signal acquisition part, a signal processing part, a PWM signal output control part, and a heating part; the working instruction part is composed of a TLP521-1 optical coupler (2); the signal acquisition part is composed of an LM324 operational amplifier (1) and a TBC25SYH current sensor (5); the signal processing part is composed of an STC12C5410AD single-chip microcomputer (7); the PWM signal output control part is composed of a TLP521-1 optical coupler (3) and an FQL40N50 field effect transistor (4); and the heating part is composed of a heating element (6) of the electric heating device.

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