CN201001108Y

CN201001108Y - High voltage isolation electronic switch

Info

Publication number: CN201001108Y
Application number: CNU2007201179527U
Authority: CN
Inventors: 罗家杰; 祝豆豆; 黄海龙; 黎雄军
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-01-10
Filing date: 2007-01-10
Publication date: 2008-01-02
Anticipated expiration: 2017-01-10

Abstract

The utility model relates to a high voltage isolation electronic switch, which is used for switch the signal on the automatic selection intelligent digital multi-meter in the measuring function. The high voltage isolation electronic switch consists of a DC-DC direct current power converter connected with a high voltage MOSFET, the DC-DC direct current power converter boosts the inputted DC signal voltage, and the outputted DC signal voltage controls the grid of the high voltage MOSFET, to make the MOSFET turned on to realize the control. Compared with the prior art, because the utility model is not adopted a light activated element with expensive price, but adopted a ordinary electric component, to make the cost of the whole switch is greatly decreased, in particular the DC-DC direct current power converter can be replaced by a prior mature DC-DC isolation module, the cost is low, the reliability is increased, the manufacture art is simplified, and the production cycle is shortened; compared to the prior the photoelectric switch, the whole electronic switch has no light energy loss, the power consumption is lower, and the electronic switch has the energy saving effect.

Description

High pressure insulating electron switch

Technical field

The utility model relates to a kind of Intelligent Digital multimeter, especially relates to the high-pressure electronic switch that signal switches that is used on the Intelligent Digital multimeter that a kind of measurement function can select automatically.

Background technology

Traditional digital multimeter adopts dial handover measurement signal, realizes different measurement functions.Need realize measurement function by the conversion dial to unlike signal.The Intelligent Digital multimeter can be judged the needed function of selection automatically by the variation of main control singlechip MCU signal to external world, and the personage who is well suited for non-electric class specialty uses.Realize automatic selection function, need switch signal.Be used for the high-pressure electronic switch that signal switches, scheme has optical coupled switch and mechanical relay at present.Mechanical relay needing to be not suitable for the intelligent digital multimeter of frequent diverter switch owing to the restriction in useful life.

Referring to Fig. 1, high pressure optocoupler 3, frame of broken lines part among the figure is by certain electric current (3-10 milliampere) being provided to control signal input port 1, making that inner LED 2 is luminous, making photoelectricity MOSFET conducting realize controlled function.The actual manufacturing of this high pressure optical coupled switch is inconvenient, and the production cycle is long, the cost height.

The utility model content

Technical problem to be solved in the utility model is: the high pressure insulating electron switch that provides a kind of signal that is used on the digital multimeter to switch solves existing optical coupled switch cost height, long problem of production cycle.

For solving the problems of the technologies described above, the utility model proposes following technical scheme: a kind of high pressure insulating electron switch, connecting high-voltage MOSFET by the DC-DC dc power converter constitutes, the direct-flow signal voltage that the DC-DC dc power converter raises and imports, the grid of the direct voltage control high-voltage MOSFET of output makes the MOSFET conducting realize control.

Described DC-DC dc power converter preferred version is: be made of oscillating circuit, transformer and filter rectifier, wherein Shu Ru direct voltage control signal outputting oscillation signal behind oscillating circuit boosts after filter rectifier is controlled the direct-current control voltage of MOSFET conducting to described high-voltage MOSFET grid output through transformer coupled again.

The beneficial effects of the utility model are: compared to existing technology, owing to do not adopt the higher light-sensitive element of price, comprise emitting led and photosensitive MOSFET, but adopt common electronic component, and this makes the cost of whole switch that bigger reduction be arranged, particularly the DC-DC dc power converter can adopt the DC-DC isolation module of present maturation to replace, cost is very low, increased reliability, simplified manufacturing process, the production cycle shortens; The existing relatively optoelectronic switch of whole electronic switch does not have optical energy loss, and is low in energy consumption a lot, has energy-saving effect.

Description of drawings

Fig. 1 is the structural representation of optical coupled switch in the prior art.

Fig. 2 is an electrical block diagram of the present utility model.

Accompanying drawing identifier declaration: control signal input port 1, emitting led 2, high pressure optocoupler 3, DC-DC dc power converter 4, turn-on control circuit 5, reverser U1A, reverser U1B, reverser U1C, filter resistance R1, filter capacitor C1, rectifier diode D1, transformer T1, oscillation resistance R2, oscillating capacitance C2, coupling capacitance C3, NMOSFET pipe Q1 and NMOSFET pipe Q2.

Embodiment

As shown in Figure 2, the utility model provides a kind of high pressure insulating electron switch, has high pressure between the source electrode of high end finger MOSFET and the drain electrode.Connect high-voltage MOSFET by the DC-DC dc power converter and constitute, the direct-flow signal voltage that the DC-DC dc power converter raises and imports, the grid of the direct voltage control high-voltage MOSFET of output makes the MOSFET conducting realize control.The DC-DC dc power converter is by a direct voltage being converted to the electronic device of other direct voltage.Ripe now DC-DC dc power converter has the DC-DC isolation module, also can adopt the circuit connection structure of solid box among Fig. 2.

Among Fig. 2, the DC-DC dc power converter is made of oscillating circuit, transformer and filter rectifier.Oscillating circuit is by reverser U1A, U1B, U1C, oscillation resistance R2, and oscillating capacitance C2 and coupling capacitance C3 constitute.Wherein reverser U1A, U1B, U1C are connected in series successively with coupling capacitance C3, and oscillation resistance R2 and reverser U1A also connect, and the branch road that oscillating capacitance C2 and reverser U1A, U1B are serially connected is connected in parallel, and coupling capacitance C3 is connected with primary coil on the transformer T1.Oscillating circuit is by being connected to form grounded circuit with transformer T1 primary coil.Filter rectifier is made of diode D1, filter resistance R1 and filter capacitor C1.Filter resistance R1 and filter capacitor C1 compose in parallel filter circuit, and filter circuit is connected in series with the secondary coil of diode D1, transformer T1 respectively and forms the loop.Control circuit whether conducting NMOSFET (N channel enhancement MOSFET) pipe Q1 and NMOSFET pipe Q2 and connect after be concatenated into again in the loop of filter rectifier, wherein the grid of NMOSFET pipe Q1 and NMOSFET pipe Q2 is attempted by the high level end of filter rectifier, and their source electrode is connected in the loop of filter rectification.The DC-DC dc power converter is controlled the MOSFET conducting by control voltage.

Reverser U1A, U1B, U1C can adopt the reverser such as 4069.Be input to the reverser U1A of DC-DC dc power converter by control signal input port 1 from a 3V dc low-voltage signal of telecommunication of the high level of main control MCU single-chip processor i/o mouth, (oscillator also can be other forms to become low-voltage AC through oscillating circuit, for example available existing single chip oscillator is replaced), export a square-wave signal is coupled to T1 by capacitor C 3 primary coil.The current rectifying and wave filtering circuit that the AC signal that the secondary coil of T1 is coupled to is formed by diode D1, capacitor C 1, resistance R 1, form the DC power supply of a 4-6V, then control the grid of high-voltage MOSFET, make and NMOSFET Q1, Q2 conducting can allow turn-on control circuit 5 realize and high press polish idol 3 identical functions.When control signal is 0V (low level of MCU I/O mouth), oscillator is not worked, and the T1 secondary is responded to less than signal, and the voltage at capacitor C 1 two ends is 0V, and NMOSFET Q1, Q2 turn-off.Reach the effect of switch.

Solid box part 4 among Fig. 2 can be replaced with ripe now DC-DC isolation module, can dwindle the PCB usable floor area, increases reliability, and cost is also low.

Claims

1, a kind of high pressure insulating electron switch, it is characterized in that: described electronic switch connects high-voltage MOSFET by the DC-DC dc power converter and constitutes, the direct-flow signal voltage that the DC-DC dc power converter raises and imports, the grid of the direct voltage control high-voltage MOSFET of output makes the MOSFET conducting realize control.

2, high pressure insulating electron switch as claimed in claim 1, it is characterized in that: described DC-DC dc power converter is made of oscillating circuit, transformer and filter rectifier, wherein Shu Ru direct voltage control signal outputting oscillation signal behind oscillating circuit boosts after filter rectifier is controlled the direct-current control voltage of MOSFET conducting to described high-voltage MOSFET grid output through transformer coupled again.

3, high pressure insulating electron switch as claimed in claim 2 is characterized in that: described oscillating circuit is by reverser (U1A, U1B, U1C), oscillation resistance (R2), and oscillating capacitance (C2) and coupling capacitance (C3) constitute; Wherein reverser (U1A, U1B, U1C) is connected in series successively with coupling capacitance (C3), oscillation resistance (R2) and reverser (U1A) also connect, oscillating capacitance (C2) is connected in parallel with the branch road that reverser (U1A, U1B) is serially connected, and coupling capacitance (C3) is connected with described transformer; Oscillating circuit is by being connected to form grounded circuit with described primary of transformer.