Input under-voltage/over-voltage protection circuit

An overvoltage protection circuit, input undervoltage technology, applied in the protection of undervoltage or no voltage reaction, overvoltage reaction protection, etc., can solve the problems of program confusion, wrong timing, latch-up, etc., to achieve The effect of preventing program confusion

Active Publication Date: 2010-05-26
VERTIV CORP
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] figure 2 It is a schematic diagram of the circuit structure of the detection and protection circuit composed of transistors, and its working sequence diagram is as follows image 3 As shown, the principle is: when the input voltage drops, if the input voltage starts to drop at time t1, the input sampling voltage of the sampling circuit starts to drop at the same time, and the input voltage drops to the input undervoltage protection point at time t2, and the corresponding input sampling voltage drops to Input the undervoltage shutdown point, the output of the PWM chip is turned off, and the output voltage begins to drop; in the period from t2 to the time period, the input voltage begins to rise after falling for a period of time, and at time t3 because the input voltage rises beyond the input undervoltage protection point, sampling The voltage correspondingly starts to rise to the input undervoltage start point (because there is no hysteresis, the undervoltage shutdown point and the undervoltage start point are almost the same), the PWM chip has output again, and the output voltage starts to rise. If the output voltage drops within the unsafe range of the output voltage In this case, the output power supply to the DSP or CPU may cause program confusion or latch phenomenon, and even damage the DSP or CPU chip; at the same time, the range of each output voltage drop and the starting point and speed of the rise If it is not controlled, the timing of each output voltage may be incorrect, especially when the input voltage undervoltage protection occurs more frequently, the output timing of each channel may be more chaotic, resulting in unexpected errors or even damage to the subsequent circuit

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Input under-voltage/over-voltage protection circuit
  • Input under-voltage/over-voltage protection circuit
  • Input under-voltage/over-voltage protection circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] Such as Figure 4 As shown, an input undervoltage or overvoltage protection circuit of the present invention includes a voltage sampling circuit 1, a logic control circuit 2, a hysteresis control circuit 3, and a sampling output holding circuit 4.

[0054] Such as Figure 7 As shown, the voltage sampling circuit 1 is a series branch composed of a first resistor R1 and a first Zener diode D1. One end of the first resistor R1 is connected to the direct current input source DC, and the other end is connected to the cathode of the first Zener diode D1. The other end of the first Zener diode D1 serves as the output end of the voltage sampling circuit 1. The logic control circuit 2 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch tube Q1, and a second switch tube Q2. One end of the second resistor R2 is connected to one end of the third resistor R3 and then connected to the direct current input source DC. One end of the fourth resistor R...

Embodiment 2

[0061] Such as Picture 10 As shown, compared with the first embodiment, this embodiment only removes the sample output holding circuit 4. Among them, the working principle of the hysteresis control circuit 3 is (take undervoltage protection as an example): when the input voltage is low (below the input undervoltage point), the first zener diode D1 and the second zener diode D2 are not conducting , The first switching tube Q1 is turned off, Q2 is turned on, the PWM control pin is pulled low, the PWM has no output, and it is in the undervoltage protection state. The collector voltage of the Q2 tube is low, the Q3 tube does not conduct, and the voltage regulator tube D2 is not bypassed. When the input voltage is greater than the regulated voltage of the regulator tubes D1 and D2 plus the sum of the conduction voltage drop of the Q1 tube base V D1 +V D2 +V beQ1 At this time, the Q1 tube is turned on, the Q2 tube is off, and the Q3 tube is turned on, the circuit starts to start, a...

Embodiment 3

[0063] Such as Picture 11 As shown, an input under-voltage or over-voltage protection circuit includes a voltage sampling circuit 1, a logic control circuit 2 and a sampling output holding circuit 4.

[0064] The voltage sampling circuit 1 is a series branch composed of a first resistor R1 and a first Zener diode D1. One end of the first resistor R1 is connected to the direct current input source DC, and the other end is connected to the cathode of the first Zener diode D1. The other end of the first Zener diode D1 serves as the output end of the voltage sampling circuit 1. The logic control circuit 2 includes a second resistor R2, a fourth resistor R4, a first switch tube Q1, and a second switch tube Q2. One end of the second resistor R2 is connected to the DC input source. One end of the fourth resistor R4 is connected to the base of the first switching tube Q1 as the input end of the logic control circuit 2 and is connected to the output end of the voltage sampling circuit ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

This invention relates to a new type of input low voltage / over voltage protection circuit used in assistant supply including a voltage sample circuit, a logic control circuit, a back lash control circuit used in low voltage back lash processing said sample output to be output to said logic control circuit, which ensures outputs of the assistant supply can fall to the safety low voltage and then starts up when the input meets with quick falling, transient, glittering or low frequency interference to avoid logic errors.

Description

[Technical Field] [0001] The invention relates to an input undervoltage or overvoltage protection circuit, in particular to an input undervoltage or overvoltage protection circuit applied to an auxiliary power supply. [Background technique] [0002] Because the previous under-voltage or over-voltage protection is mainly to prevent damage to the input devices, PCB wiring, etc. due to excessive input current when the input low-voltage output is fully loaded, or the power supply is damaged due to excessive input voltage, mainly It is designed to protect the main power circuit, and generally does not require undervoltage or overvoltage protection for the auxiliary power supply itself. But at present, the requirements for the environment and compatibility of power products are getting higher and higher, and the input voltage range is getting wider and wider. In addition, the existence of various input interferences (such as rapid drops, transients, flicker, etc.) The requirements of ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): H02H3/20H02H3/24
Inventor 吴连日
Owner VERTIV CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap