CA1106004A - Switching device - Google Patents
Switching deviceInfo
- Publication number
- CA1106004A CA1106004A CA300,200A CA300200A CA1106004A CA 1106004 A CA1106004 A CA 1106004A CA 300200 A CA300200 A CA 300200A CA 1106004 A CA1106004 A CA 1106004A
- Authority
- CA
- Canada
- Prior art keywords
- operational amplifier
- output
- inverting input
- operational
- voltage divider
- 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.)
- Expired
Links
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- Amplifiers (AREA)
Abstract
Abstract of the Disclosure.
According to the invention, a switching device based on an active switching element is built around an operatio-nal amplifier featuring two switching components connected in series in the negative feedback circuit. The positive feedback circuit of the operational amplifier comprises a voltage divider having two resistors and an operational am-plifier whose non-inverting input is coupled to the centre tap of the power sources of both operational amplifiers and the output busbar. The inverting input of the operational am-plifier of the voltage divider is connected to the non-inven-ting input of the operational amplifier of the active switch-ing element whose output is coupled to the output of the ope-rational amplifier of the voltage divider via series-connec-ted resistors. One of the resistors is connected between the output and the non-inverting input of the operational ampli-fier of the active switching element.
According to the invention, a switching device based on an active switching element is built around an operatio-nal amplifier featuring two switching components connected in series in the negative feedback circuit. The positive feedback circuit of the operational amplifier comprises a voltage divider having two resistors and an operational am-plifier whose non-inverting input is coupled to the centre tap of the power sources of both operational amplifiers and the output busbar. The inverting input of the operational am-plifier of the voltage divider is connected to the non-inven-ting input of the operational amplifier of the active switch-ing element whose output is coupled to the output of the ope-rational amplifier of the voltage divider via series-connec-ted resistors. One of the resistors is connected between the output and the non-inverting input of the operational ampli-fier of the active switching element.
Description
6~4 .
This invention relates to means of electric signal switching and, in particular, to a switching device.
; The invention can be used in multistage switchgear installations.
There is known a switching device (U.S.S.R. Inventor's Certificate No. 427,473, published May 5, 1974) which is an active switching element built around an operational amplifier with two series-connected switching components in the negative feed-back circuit and a voltage divider in the positive feed-back circuit. The voltage divider comprises two series-connected potentiometers, the slide of the first potentiometer being connected to the output of the operational amplifier via a capacitor, whereas the slide of the second potentiometer is connected to its non-inverting input. When switching elements are turned on, the operational amplifier is enveloped by negative and positive feedback circuits and the transient resistance of the switching element is reduced to an insignificant value.
However, the value and instability of the transient resistance grow considerably with the variation of the frequency of the switched electric signal. This drawback causes errors in switching-, when the frequency of the switched signal changes, and limits the area of application of switching devices base on an active switching element featuring two feedback circuits.
The object of the invention is to increase the accura-~ 2-~6g~4 - cy of commutation with the frequency of switched electric signals changing within a wide frequency range.
According to the present invention there is provided a switching device based on an active switching element, comprising: a first operational amplifier having a negative feedback circuit and a positive feedback circuit, an inverting and a non-inverting inputs and an output; an input busbar; a control busbar; first and second switching components connected in series and connected to said negative feedback circuit of said first operational amplifier, said first and second switching components having control inputs connected to said control busbar and a centre tap of said first and second switching components being connected to said input busbar; a voltage divider connected to said positive feedback circuit of said first operational amplifier; a first resistor in said voltage divider, said first resistor being connected between said output and said non-inverting input of said first operational amplifier;
a second resistor in said voltage divider and connected in series with said first resistor; a second operational amplifier in said voltaye divider and having a non-inverting input and an inverting input and an output, said output of said second operational amplifier being connected through first resistor and said second resistor in series to said output of said first operational amplifier; said inverting input of said second operational amplifier being connected to said non-inverting input of said operational amplifier; an output busbar; a first power source and a second power source for said first operational amplifier and said second operational amplifier; said first and second power sources having a centre tap connected to said output busbar and said non-inverting input of said second oper-ational amplifier~
The invention will now be described in more detail, B
by way of example only, with re~erence to the accompanying drawings, in which the single figure is a circuit diagram of a switching device in accordance with one embodiment of the invention.
A switching device, according to the invention, based on an active switching element is built around an operatio-.
-3a-~' 6 O~ ~
nal amplifier 1 whose negative feedback circuit comprises series-connected switching compone~ts 2 and 3. ~he positive ~eedback circuit comprises a voltage dividex having an operational ampli~ier 4 ~hose non-inverting input 5 is ccn-nected to an output busbar 6 and a center tap 7 of power sources 8 and 9 of the operational amplifiers 1 and 4. 3e-sides, the voltage divider ha.s two series-connected resis-tors 10 and 11, the resistor lO being placed between a non-inverting input 12 and an output 13 of the operational am-plifier 1, which is also connected to an output 14 ol the operational amplifier 4 via t~e resistors 10 and 11. An in-verting input 15 o~ the operational amplifier 4 is connected to the non-inverting input 12 of the operational amplifier 1.
An input busbar 16 of the device is coupled to the switching components 2 and 3 connected ~n the center tap 17 and their control electrodes 18 and 19 are connected to a control bus-bar 20.
~he switching device operates as follows.
~ he signal supplied fro~ the control busbar 20 closes the switching components 2 and 3. A certain transient resistance is set between the input busbar 16 and the OUbput busbar 6.
~he output voltage of the operational amplifier 1 is applied via the voltage divider, its one leg being the resistor 10 and the other being the ~requency dep~ndent resistance of the circuit comprising the operational amplifier 4 featuring the resistor 11 in the negative feedback circuit, to the non-in-verting input 12 of the operational amplifier 1. ~he frequency function of the voltage divider transmission ratio is opposite ~.
~6~4 . ~
to the frequency fu~ction of the voltage transmission ratioo~ the operational ampli~ier 1. ~hat is why the output volt-age of the operational ampli~ier 1 is maintained constant through a wide fre~uency range. As the output voltage of the operational amplifier 1 is constant, the transient resistance between the input and output busbars of the device is also kept constant and close to zero. As a result the accurac~ of commutation is increased with variations o~ the frequency of the electric signals within a w~e range.
.
- .. . .
, ~ - - , .~ - .
- -- . . ~ .,
This invention relates to means of electric signal switching and, in particular, to a switching device.
; The invention can be used in multistage switchgear installations.
There is known a switching device (U.S.S.R. Inventor's Certificate No. 427,473, published May 5, 1974) which is an active switching element built around an operational amplifier with two series-connected switching components in the negative feed-back circuit and a voltage divider in the positive feed-back circuit. The voltage divider comprises two series-connected potentiometers, the slide of the first potentiometer being connected to the output of the operational amplifier via a capacitor, whereas the slide of the second potentiometer is connected to its non-inverting input. When switching elements are turned on, the operational amplifier is enveloped by negative and positive feedback circuits and the transient resistance of the switching element is reduced to an insignificant value.
However, the value and instability of the transient resistance grow considerably with the variation of the frequency of the switched electric signal. This drawback causes errors in switching-, when the frequency of the switched signal changes, and limits the area of application of switching devices base on an active switching element featuring two feedback circuits.
The object of the invention is to increase the accura-~ 2-~6g~4 - cy of commutation with the frequency of switched electric signals changing within a wide frequency range.
According to the present invention there is provided a switching device based on an active switching element, comprising: a first operational amplifier having a negative feedback circuit and a positive feedback circuit, an inverting and a non-inverting inputs and an output; an input busbar; a control busbar; first and second switching components connected in series and connected to said negative feedback circuit of said first operational amplifier, said first and second switching components having control inputs connected to said control busbar and a centre tap of said first and second switching components being connected to said input busbar; a voltage divider connected to said positive feedback circuit of said first operational amplifier; a first resistor in said voltage divider, said first resistor being connected between said output and said non-inverting input of said first operational amplifier;
a second resistor in said voltage divider and connected in series with said first resistor; a second operational amplifier in said voltaye divider and having a non-inverting input and an inverting input and an output, said output of said second operational amplifier being connected through first resistor and said second resistor in series to said output of said first operational amplifier; said inverting input of said second operational amplifier being connected to said non-inverting input of said operational amplifier; an output busbar; a first power source and a second power source for said first operational amplifier and said second operational amplifier; said first and second power sources having a centre tap connected to said output busbar and said non-inverting input of said second oper-ational amplifier~
The invention will now be described in more detail, B
by way of example only, with re~erence to the accompanying drawings, in which the single figure is a circuit diagram of a switching device in accordance with one embodiment of the invention.
A switching device, according to the invention, based on an active switching element is built around an operatio-.
-3a-~' 6 O~ ~
nal amplifier 1 whose negative feedback circuit comprises series-connected switching compone~ts 2 and 3. ~he positive ~eedback circuit comprises a voltage dividex having an operational ampli~ier 4 ~hose non-inverting input 5 is ccn-nected to an output busbar 6 and a center tap 7 of power sources 8 and 9 of the operational amplifiers 1 and 4. 3e-sides, the voltage divider ha.s two series-connected resis-tors 10 and 11, the resistor lO being placed between a non-inverting input 12 and an output 13 of the operational am-plifier 1, which is also connected to an output 14 ol the operational amplifier 4 via t~e resistors 10 and 11. An in-verting input 15 o~ the operational amplifier 4 is connected to the non-inverting input 12 of the operational amplifier 1.
An input busbar 16 of the device is coupled to the switching components 2 and 3 connected ~n the center tap 17 and their control electrodes 18 and 19 are connected to a control bus-bar 20.
~he switching device operates as follows.
~ he signal supplied fro~ the control busbar 20 closes the switching components 2 and 3. A certain transient resistance is set between the input busbar 16 and the OUbput busbar 6.
~he output voltage of the operational amplifier 1 is applied via the voltage divider, its one leg being the resistor 10 and the other being the ~requency dep~ndent resistance of the circuit comprising the operational amplifier 4 featuring the resistor 11 in the negative feedback circuit, to the non-in-verting input 12 of the operational amplifier 1. ~he frequency function of the voltage divider transmission ratio is opposite ~.
~6~4 . ~
to the frequency fu~ction of the voltage transmission ratioo~ the operational ampli~ier 1. ~hat is why the output volt-age of the operational ampli~ier 1 is maintained constant through a wide fre~uency range. As the output voltage of the operational amplifier 1 is constant, the transient resistance between the input and output busbars of the device is also kept constant and close to zero. As a result the accurac~ of commutation is increased with variations o~ the frequency of the electric signals within a w~e range.
.
- .. . .
, ~ - - , .~ - .
- -- . . ~ .,
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A switching device based on an active switching element, comprising:
(a) a first operational amplifier having a negative feedback circuit and a positive feedback circuit, an inverting and a non-inverting inputs and an output;
(b) an input busbar;
(c) a control busbar;
(d) first and second switching components connected in series and connected to said negative feedback circuit of said first operational amplifier, said first and second switching components having control inputs connected to said control busbar and a centre tap of said first and second switching components being connected to said input busbar;
(e) a voltage divider connected to said positive feed-back circuit of said first operational amplifier;
(f) a first resistor in said voltage divider, said first resistor being connected between said output and said non-inverting input of said first operational amplifier;
(g) a second resistor in said voltage divider and connected in series with said first resistor;
(h) a second operational amplifier in said voltage divider and having a non-inverting input and an inverting input and an output, said output of said second operational amplifier being connected through first resistor and said second resistor in series to said output of said first operational amplifier;
said inverting input of said second operational amplifier being connected to said non-inverting input of said first operational amplifier;
(i) an output busbar;
(j) a first power source and a second power source for said first operational amplifier and said second operational amplifier, said first and second power sources having a centre tap connected to said output busbar and said non-inverting input of said second operational amplifier.
(a) a first operational amplifier having a negative feedback circuit and a positive feedback circuit, an inverting and a non-inverting inputs and an output;
(b) an input busbar;
(c) a control busbar;
(d) first and second switching components connected in series and connected to said negative feedback circuit of said first operational amplifier, said first and second switching components having control inputs connected to said control busbar and a centre tap of said first and second switching components being connected to said input busbar;
(e) a voltage divider connected to said positive feed-back circuit of said first operational amplifier;
(f) a first resistor in said voltage divider, said first resistor being connected between said output and said non-inverting input of said first operational amplifier;
(g) a second resistor in said voltage divider and connected in series with said first resistor;
(h) a second operational amplifier in said voltage divider and having a non-inverting input and an inverting input and an output, said output of said second operational amplifier being connected through first resistor and said second resistor in series to said output of said first operational amplifier;
said inverting input of said second operational amplifier being connected to said non-inverting input of said first operational amplifier;
(i) an output busbar;
(j) a first power source and a second power source for said first operational amplifier and said second operational amplifier, said first and second power sources having a centre tap connected to said output busbar and said non-inverting input of said second operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA300,200A CA1106004A (en) | 1978-03-31 | 1978-03-31 | Switching device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA300,200A CA1106004A (en) | 1978-03-31 | 1978-03-31 | Switching device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1106004A true CA1106004A (en) | 1981-07-28 |
Family
ID=4111125
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA300,200A Expired CA1106004A (en) | 1978-03-31 | 1978-03-31 | Switching device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1106004A (en) |
-
1978
- 1978-03-31 CA CA300,200A patent/CA1106004A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |