CN204615787U - A kind of 0 ~ 28V step voltage generator - Google Patents

Abstract

The utility model discloses a kind of 0 ~ 28V step voltage generator, comprises 555 timers, 7905 three terminal regulators, NPN type triode Q1, PNP type triode Q2, N-type metal-oxide-semiconductor, electric capacity C5, electric capacity C6 and electric capacity C7; First pin GND end of described 555 timers is connected with signal ground end GND, its the second pin low triggering end is connected with signal ground end SGND by electric capacity C4, and its 3rd pin output is connected with the base stage of NPN type triode Q1 and PNP type triode Q2 respectively by resistance R3.Pulse generator part of the present utility model can generation per second pulse, namely to the test per second of DC/DC module once, saved manpower greatly, measuring accuracy also improves greatly simultaneously, uses in the test of the DC/DC module in Aeronautics and Astronautics field at present.

Description

A kind of 0 ~ 28V step voltage generator

Technical field

The utility model relates to a kind of 0 ~ 28V step voltage generator.

Background technology

In recent years, along with a large amount of uses of DC/DC converter, the test of DC/DC converter starting characteristic is also increasingly extensive.Tested in DC/DC starting characteristic circuit in the past and generally use transistor, mainly there is transistor oneself power consumption large, response speed is generally tens nanometers, shortcoming fast not.

Utility model content

The utility model object is that the defect existed for prior art provides a kind of 0 ~ 28V step voltage generator.

The utility model for achieving the above object, adopt following technical scheme: a kind of 0 ~ 28V step voltage generator, comprises 555 timers, 7905 three terminal regulators, NPN type triode Q1, PNP type triode Q2, N-type metal-oxide-semiconductor, electric capacity C5, electric capacity C6 and electric capacity C7;

First pin GND end of described 555 timers is connected with signal ground end GND, its the second pin low triggering end is connected with signal ground end SGND by electric capacity C4, its the 3rd pin output is connected with the base stage of NPN type triode Q1 and PNP type triode Q2 respectively by resistance R3, the direct clear terminal of its 4th pin is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 5th pin control voltage end is connected with signal ground end SGND by electric capacity C3, its the 6th pin high-triggering end is successively by resistance R2, resistance R1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 7th pin discharge end is connected with the node of resistance R1 with described resistance R2, its the 8th pin power end is connected with the direct clear terminal of its 4th pin, wherein, second pin low triggering end of described 555 timers is also connected with the 6th pin high-triggering end,

First pin power input of described 7905 three terminal regulators is connected with outside 15V power supply, and be connected with signal ground end SGND by electric capacity C1, its second pin GND end is connected with signal ground end SGND, and its 3rd pin power output end is connected with signal ground end SGND by electric capacity C2;

The collector electrode of described NPN type triode Q1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, and the collector electrode of described PNP type triode Q2 is connected with signal ground end SGND; The grid of described N-type metal-oxide-semiconductor is connected with the emitter of described NPN type triode Q1 and PNP type triode Q2 respectively, and its drain electrode is connected with outside 28V power supply, and its source electrode is connected with signal ground end SGND;

One end of described electric capacity C5 is connected with power ground end PGND, and the other end is connected with the signal output part output of described 555 timers, and is connected with signal ground end SGND by switch S 1; Described electric capacity C6 and electric capacity C7 is also connected between outside 28V power supply and described power ground end PGND.

The beneficial effects of the utility model: in the utility model, because pulse generator can generation per second pulse, namely to the test per second of DC/DC module once, save manpower greatly, measuring accuracy also improves greatly simultaneously, uses in the test of the DC/DC module in Aeronautics and Astronautics field at present.

Accompanying drawing explanation

Fig. 1 is 0 ~ 28V step generator circuit theory diagrams of the present utility model.

Embodiment

Shown in Fig. 1, relate to a kind of 0 ~ 28V step voltage generator, comprise 555 timers, 7905 three terminal regulators, NPN type triode Q1, PNP type triode Q2, N-type metal-oxide-semiconductor, electric capacity C5, electric capacity C6 and electric capacity C7;

First pin GND end of described 555 timers is connected with signal ground end GND, its the second pin low triggering end is connected with signal ground end SGND by electric capacity C4, its the 3rd pin output is connected with the base stage of NPN type triode Q1 and PNP type triode Q2 respectively by resistance R3, the direct clear terminal of its 4th pin is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 5th pin control voltage end is connected with signal ground end SGND by electric capacity C3, its the 6th pin high-triggering end is successively by resistance R2, resistance R1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 7th pin discharge end is connected with the node of resistance R1 with described resistance R2, its the 8th pin power end is connected with the direct clear terminal of its 4th pin, wherein, second pin low triggering end of described 555 timers is also connected with the 6th pin high-triggering end,

First pin power input of described 7905 three terminal regulators is connected with outside 15V power supply, and be connected with signal ground end SGND by electric capacity C1, its second pin GND end is connected with signal ground end SGND, and its 3rd pin power output end is connected with signal ground end SGND by electric capacity C2;

The collector electrode of described NPN type triode Q1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, and the collector electrode of described PNP type triode Q2 is connected with signal ground end SGND; The grid of described N-type metal-oxide-semiconductor is connected with the emitter of described NPN type triode Q1 and PNP type triode Q2 respectively, and its drain electrode is connected with outside 28V power supply, and its source electrode is connected with signal ground end SGND;

One end of described electric capacity C5 is connected with power ground end PGND, and the other end is connected with the signal output part output of described 555 timers, and is connected with signal ground end SGND by switch S 1; Described electric capacity C6 and electric capacity C7 is also connected between outside 28V power supply and described power ground end PGND.

According to Fig. 1, after switching on power, electric capacity C4 is charged, as the 6th pin voltage V of 555 timers _crise to the 8th pin voltage V _cc2/3 time, make the 6th pin voltage V _ofor low level, the discharge diode conducting of 555 timer inside simultaneously, now electric capacity C4 is by resistance R2 and discharge diode electric discharge, the 6th pin voltage V _cdecline.As the 6th pin voltage V _cdrop to the 8th pin voltage V _cc1/3 time, its 3rd pin voltage V _oupset is high level.Time needed for capacitor C4 discharges is t _pL=R2C4ln2 ≈ 0.7R2C4.At the end of electric discharge, discharge diode ends, the 8th pin voltage V _ccto be charged to capacitor C4 by resistance R1, R2, the 6th pin voltage V _cby the 8th pin voltage V _cc1/3 rise to 2/3.The required time is: t _pH=(R1+R2) C4ln2 ≈ 0.7 (R1+R2) C4.As the 6th pin voltage V _cwhen rising to 2/3 of the 8th pin voltage Vcc, circuit overturns again as low level, thus the 3rd pin output voltage Vo obtains periodic square wave.

In figure, the multivibrator of 555 timer compositions is pulse generator part of the present utility model.The square wave exported by 555 timers drives triode Q1, Q2 thus controls conducting and the cut-off of N-type metal-oxide-semiconductor, holds the step voltage of generation 0 ~ 28V at the signal output part output of 555 timers.The model of triode Q1 is TIP31C, and the model of triode Q2 is TIP32C.The conduction voltage drop of triode Q1, Q2 is 1.2V, and metal-oxide-semiconductor model is IRF540N.When the 3rd pin of 555 timers exports high level, triode Q1 conducting, the grid voltage VG=3.8V of metal-oxide-semiconductor, metal-oxide-semiconductor conducting, when switch S 1 closes, Voutput=28V; When the 3rd pin output low level of 555 timers, triode Q2 conducting, the grid voltage VG=1.2V of metal-oxide-semiconductor, the gate threshold voltage V of metal-oxide-semiconductor _{gS (th)}for 2.0V, metal-oxide-semiconductor conducting, when switch S 1 closes, Voutput=0V.Due to 555 timers outputs are periodic square waves, and thus when switch S 1 closes, OUTPUT end can export periodic 0 ~ 28V step voltage.

The switch triode used due to traditional 0 ~ 28V step voltage generator can bring loss large, and need increase radiator, volume is large, the problems such as response speed is slow.Being metal-oxide-semiconductor by changing switch triode, and changing drive circuit, significantly reducing loss, and improve switching speed, improve the accuracy of test.

In the utility model, described pulse generator is in view of the switching frequency of MOS is high, conduction loss is little, and the pulse frequency that 555 timers send is also high, thus saves manpower, and pulse precision is also higher.

The foregoing is only preferred embodiment of the present utility model, not in order to limit the utility model, all within spirit of the present utility model and principle, any amendment done, equivalent replacement, improvement etc., all should be included within protection range of the present utility model.

Claims (1)

1. 0 ~ 28V step voltage generator, is characterized in that, comprises 555 timers, 7905 three terminal regulators, NPN type triode Q1, PNP type triode Q2, N-type metal-oxide-semiconductor, electric capacity C5, electric capacity C6 and electric capacity C7;

First pin GND end of described 555 timers is connected with signal ground end GND, its the second pin low triggering end is connected with signal ground end SGND by electric capacity C4, its the 3rd pin output is connected with the base stage of NPN type triode Q1 and PNP type triode Q2 respectively by resistance R3, the direct clear terminal of its 4th pin is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 5th pin control voltage end is connected with signal ground end SGND by electric capacity C3, its the 6th pin high-triggering end is successively by resistance R2, resistance R1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, its the 7th pin discharge end is connected with the node of resistance R1 with described resistance R2, its the 8th pin power end is connected with the direct clear terminal of its 4th pin, wherein, the second pin low triggering end of described 555 timers is also connected with the 6th pin high-triggering end,

First pin power input of described 7905 three terminal regulators is connected with outside 15V power supply, and be connected with signal ground end SGND by electric capacity C1, its second pin GND end is connected with signal ground end SGND, and its 3rd pin power output end is connected with signal ground end SGND by electric capacity C2;

The collector electrode of described NPN type triode Q1 is connected with the 3rd pin power output end of described 7905 three terminal regulators, and the collector electrode of described PNP type triode Q2 is connected with signal ground end SGND; The grid of described N-type metal-oxide-semiconductor is connected with the emitter of described NPN type triode Q1 and PNP type triode Q2 respectively, and its drain electrode is connected with outside 28V power supply, and its source electrode is connected with signal ground end SGND;

One end of described electric capacity C5 is connected with power ground end PGND, and the other end is connected with the signal output part output of described 555 timers, and is connected with signal ground end SGND by switch S 1; Described electric capacity C6 and electric capacity C7 is also connected between outside 28V power supply and described power ground end PGND.