CN2840519Y

CN2840519Y - Analog sound effects processing circuit

Info

Publication number: CN2840519Y
Application number: CN 200520017740
Authority: CN
Inventors: 林伟程; 时逸凡; 李勇明; 张立颖
Original assignee: Princeton Technology Corp
Current assignee: Princeton Technology Corp
Priority date: 2005-05-06
Filing date: 2005-05-06
Publication date: 2006-11-22
Anticipated expiration: 2015-05-06

Abstract

The utility model provides an analog sound effect processing circuit. When the utility model is switched, impulse noise is reduced. An output end of an original switching circuit of the analog sound effect processing circuit is additionally provided with a group of voltage division resistance circuits. One end of the voltage division resistance circuit is connected with the output end of the original switching circuit, and the other end is connected with reference voltage. Each voltage division point of the voltage division resistance circuit is connected with a controllable switch. The other ends of the controllable switches are mutually connected to form the output end. The first controllable switch is a master control switch. When the original switching circuit is switched, the master control switch is automatically cut off for some time, other switches of the controllable switch are orderly controlled by a series of continuous short pulses, the second switch is orderly turned on and then turned off, and like this the last switch is turned on and then turned off; the last switch comes back to the second switch, and the communication is recovered by the master control switch to obtain the switching purpose.

Description

The simulation sound effect processing circuit

Technical field

This novel improvement relevant for the simulation sound effect processing circuit refers in particular to the design that reduces pulse noise when the simulation sound effect processing circuit switches.

Background technology

Ask for an interview Fig. 1, be the schematic diagram of general simulation sound effect processing circuit, signal S imports an input buffer 1 from the left side, sends into an output buffer 4 through a sound effect processing circuit 2 and a switching circuit 3 then and exports.Switching circuit 3 can be selected the output B of sound effect processing circuit 2 or the output A of input buffer 1, and sends into the input D of output buffer 4.5 of reference circuits provide reference voltage C and give input buffer 1, sound effect processing circuit 2, output buffer 4, as shown in the figure.

Usually input buffer 1 uses an operational amplifier to be used as buffer, output buffer 4 also uses an operational amplifier to be used as buffer, sound effect processing circuit 2 is handled volume, high pitch, bass, ring field audio, stereo sound effect etc., and six operational amplifiers are generally arranged approximately.

Each operational amplifier all produces offset voltage (offset voltage), supposes the about 10mV of offset voltage Δ V, and the reference voltage C of reference circuits 5 is 4.5V, then:

The output A=C+ Δ V=4.510V of input buffer 1

Output B=C+6 * Δ the V+X of sound effect processing circuit 2 (X is produced by ring field audio, stereo sound effect, about 50mV) is so B=4.610V

Therefore when switching circuit 3 switches the output A of the output B of selection sound effect processing circuits 2 or input buffer 1, produce the voltage difference of 100mV, obviously produce one the reason of " ripple " during Here it is user's toggle switch circuit 3, Here it is so-called " pulse noise ", is the most worried thing of sound equipment player.

Summary of the invention

Therefore the purpose of this utility model is to provide a kind of simulation sound effect processing circuit, is used to reduce the pulse noise when switching, comprising: input buffer has an output; Sound effect processing circuit has an output; Output buffer has an input; Reference circuits has an output, and this reference circuits is output as the reference voltage of described input buffer, described sound effect processing circuit and described output buffer; Switching circuit comprising first switch, has first end of the output that couples described input buffer; Second switch has first end of the output that couples described sound effect processing circuit, this second switch and the operation of described first switch inverse; The 3rd switch has first end of second end of second end that couples described first switch and described second switch, and has second end of the output that couples described output buffer; A plurality of voltage grading resistors are serially connected with between the output of described the 3rd switch and described reference circuits, wherein said a plurality of voltage grading resistors to each other serial connection point and the node of the output of described reference circuits be called dividing point; A plurality of dividing potential drop control switchs, be provided with corresponding to described dividing point, be coupled in separately between the output of a described dividing point and described output buffer, wherein, described switching circuit is before the output of output of switching described input buffer and described sound effect processing circuit, close described the 3rd switch earlier, taking turns starting described dividing potential drop control switch changes the magnitude of voltage of the output of described output buffer in proper order, switch described first switch and second switch again, take turns starting described dividing potential drop control switch the magnitude of voltage of the output of described output buffer is changed in proper order, start described the 3rd switch at last.

Description of drawings

Fig. 1 is the schematic diagram of general simulation sound effect processing circuit.

Fig. 2 is the schematic diagram of the utility model switching circuit.

Fig. 3 is the impulse waveform schematic diagram of the utility model control switch circuit.

Embodiment

Please refer to the design that reduces pulse noise when Fig. 2 the utility model simulation sound effect processing circuit switches, this design is in order to replace the switching circuit 3 among Fig. 1.Node_A, Node_B and Node-_D receive A, B, D 3 points of Fig. 1 respectively among Fig. 2, switch SW _ A and SW_B are original switch that switches the output B of the output A that selects input buffer 1 or sound effect processing circuit 2, the utility model additionally add switch SW-D, SW_1, SW_2, SW_3,,, SW_30 and resistor R 1, R2, R3,,, R30, it connects as shown in the figure.R30 and the SW_30 part of joining is Node_C, is connected to the reference voltage C point of Fig. 1 reference circuits 5, resistor R 1, R2, R3,,, the resistance of R30 is all the same.

The control signal of switch SW _ A and SW_B represents with SWA, SWB, switch SW _ D, SW_1, SW_2, SW_3,,, the control signal of SW_30 with SWD, SW1, SW2, SW3,,, SW30 represents.SWA, SWB and SWD, SW1, SW2, SW3,,, the waveform of SW30 asks for an interview Fig. 3.

Part Node_C is connected to the reference voltage C point of Fig. 1 reference circuits 5 because R30 and SW_30 join, therefore keep a constant voltage (for example 4.5V) in Node_C, therefore resistor R 1, R2,,, produce the effect of dividing potential drop on the R30, if Node_A is 4.510V, and SW_A is a path, SW_B opens circuit, and then resistor R 1, the R2 part of joining is 4.50967V, and the rest may be inferred by analogy.

Show among Fig. 3 when SWA by " 1 " change " 0 ", SWB during by " 0 " change " 1 ", that is when switching to the output B of sound effect processing circuit 2 by the output A of input buffer 1, the waveform of SWD becomes " 0 " in advance, SWD be " 0 " during, SW1, SW2, SW3,,, the waveform of SW30 is the short pulse that continues one by one, begin behind SW30, to get back to SW1 by SW30 again by SW1.These short pulses be used for making respectively switch SW _ 1, SW_2, SW_3,,, the SW_30 conducting.When the SW_1 conducting, SWA is still " 1 ", and the output A of input buffer 1 sends into D through R1, SW_1, so the output A of input buffer 1 is decayed a little by resistor R 1.When the SW_2 conducting, SWA is still " 1 ", and the output A of input buffer 1 sends into D through R1, R2, SW_2, so the output A of input buffer 1 is by resistor R 1+R2 and further decay.By that analogy, by the time SWA prepares in " 1 " changes " 0 ", the output A of input buffer 1 by resistor R 1+R2+R3,, ,+R30 decays.When SWA from " 1 " change " 0 ", SWB during by " 0 " change " 1 ", the voltage that send into D this moment is the 4.5V of reference voltage C, the output A of input buffer 1 has switched to the output B of sound effect processing circuit 2, impulse waveform begins to get back to SW1 by SW30 and forms the short pulse that continues one by one, so the output B that makes sound effect processing circuit 2 (as previously mentioned, suppose 4.610V) earlier by R1+R2+R3,, ,+R30 decay jointly (originally being 4.5V), progressively recover then, so the user can not hear lofty " ripple " one.In case get back to after R1, the SW_1, next step is exactly that SWD reverts to " 1 " and connects SW_D, so the output B of sound effect processing circuit 2 sends into the D point really, finishes user's toggle switch circuit and the purpose switched.

This novel spirit and scope only is subject to following claim, is not subject to the foregoing description.

Claims

1. a simulation sound effect processing circuit is used to reduce the pulse noise when switching, comprising:

Input buffer has an output (A);

Sound effect processing circuit has an output (B);

Output buffer has an input (D);

Reference circuits has an output (C), and the output of this reference circuits (C) is the reference voltage of described input buffer, described sound effect processing circuit and described output buffer;

Switching circuit, comprising:

First switch (SW_A) has first end of the output (A) that couples described input buffer;

Second switch (SW_B) has first end of the output (B) that couples described sound effect processing circuit, this second switch and described first switch (SW_A) operated in anti-phase;

The 3rd switch (SW_D) has first end of second end of second end that couples described first switch (SW_A) and described second switch (SW_B), and has second end of the output (D) that couples described output buffer;

A plurality of voltage grading resistors are serially connected with between the output (C) of described the 3rd switch (SW_D) and described reference circuits, and the node of wherein said a plurality of voltage grading resistors serial connection point to each other and the output of described reference circuits (C) is called dividing point;

A plurality of dividing potential drop control switchs are provided with corresponding to described dividing point, are coupled in separately between the output (D) of a described dividing point and described output buffer,

Wherein, described switching circuit in the output (B) of output (A) of switching described input buffer and described sound effect processing circuit before, close described the 3rd switch (SW_D) earlier, taking turns starting described dividing potential drop control switch changes the magnitude of voltage of the output (D) of described output buffer in proper order, switch described first switch (SW_A) and second switch (SW_B) again, take turns starting described dividing potential drop control switch the magnitude of voltage of the output (D) of described output buffer is changed in proper order, start described the 3rd switch (SW_D) at last.