CN1166090A - Analogue switching circuit replacing variable resistor - Google Patents
Analogue switching circuit replacing variable resistor Download PDFInfo
- Publication number
- CN1166090A CN1166090A CN 96117753 CN96117753A CN1166090A CN 1166090 A CN1166090 A CN 1166090A CN 96117753 CN96117753 CN 96117753 CN 96117753 A CN96117753 A CN 96117753A CN 1166090 A CN1166090 A CN 1166090A
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- CN
- China
- Prior art keywords
- analog switch
- pulse width
- variable resistor
- switching circuit
- pass filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Abstract
A pulse width modulated analog switch instead of thyrector features use of bidirectional analog switch to form equivalent bae thryector. Its control pin is connected to a voltage controlled pulse width modulator and changing the control voltage of the modulator can change the width ofits output pulse, so simulating the variation of equivalent resistance. The analog switch is used to isolate the control part from the controlled part and high-pass filter is used to remove high-frequency component caused by pulse width modulation.
Description
The present invention relates to applying electronic circuit engineering field, especially analog switching circuit.
Present variable resistance is to use the mechanical adjustment displacement to change resistance value, often run in the practical application and need come resistor is regulated with electric signal, way commonly used is to use various active devices such as electron tube, transistor, light-emitting diode and photo resistance assembly to be equivalent to resistor, but there is very big limitation in this equivalence, there be control signal crosstalking to manipulated signal, when being AC signal, present the problem that forward and reverse impedance does not wait when controlled.
The purpose of this invention is to provide a kind of control signal of avoiding to the crosstalking of manipulated signal, and controlled AC signal is presented the equivalent variable resistor of forward and reverse impedance symmetry.
For achieving the above object, solution of the present invention is to constitute basic equivalent variable resistor with IC1 bidirectional analog switch, the control end 3 of this analog switch is connected to a voltage control pulse width modulator, and its equivalent resistance is to realize by the pulse duty factor of regulating control end 3.The low pass filter the 5, the 6th that is provided with on the controlled path is used for the high frequency composition that the filtering pulse-width modulation brings, constituted the voltage control pulse width modulator with ic chip 2, resistance R 1, R2, capacitor C, change by control voltage VC0, cause the change of IC2 output VC pulsewidth, thereby reach the purpose that changes this equivalent variable resistor of IC1.
Good effect of the present invention is, for applying electronic circuit engineering field provide a kind of to controlled AC signal be forward and reverse impedance symmetry, control signal can not produce the equivalent controlled resistance of crosstalking to manipulated signal.
Accompanying drawing is an electrical schematic diagram of the present invention.
The present invention is described in further detail below in conjunction with the drawings and specific embodiments.
IC1 is a bidirectional analog switch.During general the use, control end Vc awards when opening signal, and 1,2 of analog switches present very little impedance, and the Vis low frequency signal arrives Vos by IC1, does not have what loss.In like manner, Vos also can turn around and be transferred to Vis.If Vc is a control signal that pulse duration is adjustable, then the bidirectional analog switch is done to turn on and off at a high speed, make low frequency signal by analog switch be divided into break-make waveform like a group " rusk ", revert to the low frequency waveform again through behind the low pass filter, but amplitude has been subjected to bidirectional analog switch " break-make " and step-down, like this, the bidirectional analog switch has just played the effect of a variable resistance.The size of its equivalent resistance is by the pulse duration decision of control end Vc, and pulse duration is wide more, and the equiva lent impedance that bidirectional analog switch I C1 presents is more little, and pulse duration is narrow more, and the equiva lent impedance that IC1 presents is big more.
Claims (3)
1. analog switching circuit, it is made up of the bidirectional analog switch, it is characterized in that: the control end of this analog switch is connected to a voltage control pulse width modulator; Be provided with low pass filter on the controlled path; This analog switch can be used for replacing variable resistor.
2. analog switch according to claim 1 is characterized in that: the voltage control pulse width modulator is made up of ic chip 2, resistance R 1, R2, capacitor C.
3. analog switch according to claim 1 is characterized in that: the one or both ends of bidirectional analog switch terminal are connected to low pass filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96117753 CN1166090A (en) | 1996-10-21 | 1996-10-21 | Analogue switching circuit replacing variable resistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96117753 CN1166090A (en) | 1996-10-21 | 1996-10-21 | Analogue switching circuit replacing variable resistor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1166090A true CN1166090A (en) | 1997-11-26 |
Family
ID=5124575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96117753 Pending CN1166090A (en) | 1996-10-21 | 1996-10-21 | Analogue switching circuit replacing variable resistor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1166090A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103597746A (en) * | 2011-06-16 | 2014-02-19 | 罗姆股份有限公司 | Analog-switch circuit and motor drive unit using same |
| CN110805934A (en) * | 2019-11-14 | 2020-02-18 | 广东美的厨房电器制造有限公司 | Electric cooking device and heating control device thereof |
-
1996
- 1996-10-21 CN CN 96117753 patent/CN1166090A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103597746A (en) * | 2011-06-16 | 2014-02-19 | 罗姆股份有限公司 | Analog-switch circuit and motor drive unit using same |
| CN103597746B (en) * | 2011-06-16 | 2016-08-31 | 罗姆股份有限公司 | Analog switching circuit and use its motor driver |
| CN110805934A (en) * | 2019-11-14 | 2020-02-18 | 广东美的厨房电器制造有限公司 | Electric cooking device and heating control device thereof |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |