Phantom microphone insertion detection circuit
By designing a phantom microphone insertion detection circuit, the insertion status of the microphone is detected by voltage changes, which solves the noise problem when the phantom microphone is inserted and realizes a stable insertion detection function.
Patent Information
- Application Number
- CN202423302507.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing phantom microphones are prone to noise problems when inserted due to the lack of insertion detection.
A phantom microphone insertion detection circuit was designed, which includes a power supply module and a detection module. The microphone insertion status is determined by the voltage change at the detection point. Combined with power supply filtering and protection circuits, instantaneous noise is avoided.
It successfully detects microphone insertion and avoids abnormal sounds at the moment of insertion without changing the interface method.
Smart Images
Figure CN223729916U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a phantom microphone insertion detection circuit. BACKGROUND
[0002] Phantom Power Definition: Phantom power is a method of transmitting DC power through audio cables, primarily used to provide power to condenser microphones and other audio equipment that requires an external power source. It is called "phantom" because the power is provided through the audio signal wires in the same XLR connector, appearing to have no additional power wires from the outside, as if the power appeared out of thin air. The common phantom power standard is 48 V, but it can also be 12V or 24V, depending on the requirements of the equipment. Most modern mixing consoles, preamplifiers, and recording interfaces provide a phantom power option.
[0003] Condenser Microphone Working Principle: Condenser microphones use the change in capacitance between two thin plates - the diaphragm and the backplate - to capture sound. When sound waves hit the diaphragm, it moves, changing the distance to the backplate and thus the capacitance value. This change is converted into an electrical signal output. To maintain the electrostatic field between the diaphragm and the backplate, as well as the built-in preamplifier, condenser microphones require an external power source. This is why phantom power is needed.
[0004] Condenser microphones that use phantom power are called phantom microphones. The phantom microphones on the market do not have a dedicated insertion detection signal pin using the standard XLR connector, and most of them do not have an insertion detection function. Suddenly inserting a microphone during power-on can cause noise. INVENTION CONTENTS
[0005] The utility model discloses a phantom microphone insertion detection circuit with a reasonable structure design, which overcomes the above-mentioned deficiencies in the prior art and realizes the phantom microphone insertion detection function.
[0006] The utility model discloses a phantom microphone insertion detection circuit that solves the above-mentioned problems by adopting the following technical scheme: a phantom microphone insertion detection circuit includes a power supply module and a microphone connector; the power supply module includes a first power supply resistor and a second power supply resistor, one end of the first power supply resistor is connected with a phantom power, the other end is connected with one end of the second power supply resistor, the other end of the second power supply resistor is connected with the microphone connector; characterized by further including a detection module; the detection module includes a first detection resistor, a second detection resistor and a detection point; one end of the first detection resistor is connected at the connection of the first power supply resistor and the second power supply resistor, the other end is connected with one end of the second detection resistor, the other end of the second detection resistor is grounded; the detection point is connected in parallel with the second detection resistor.
[0007] The detection module further comprises a protection resistor, and one end of the detection point is connected at a connection position of the first detection resistor and the second detection resistor through the protection resistor.
[0008] The detection module further comprises a detection filter capacitor, and the other end of the detection point is connected at one end of a ground connection position of the second detection resistor through the detection filter capacitor.
[0009] The power supply module further comprises a power supply filter capacitor, one end of the power supply filter capacitor is connected to the phantom power supply, and the other end is grounded.
[0010] The 3-pin of the microphone connector is connected to the microphone negative pole through the first audio coupling capacitor, and the 2-pin is connected to the microphone positive pole through the second audio coupling capacitor.
[0011] The other end of the second power supply resistor is connected to the 2-pin of the microphone connector.
[0012] The power supply module further comprises a third power supply resistor and a fourth power supply resistor, one end of the third power supply resistor is connected to the phantom power supply, the other end of the third power supply resistor is connected to one end of the fourth power supply resistor, and the other end of the fourth power supply resistor is connected to the microphone connector.
[0013] The other end of the fourth power supply resistor is connected to the 3-pin of the microphone connector.
[0014] Compared with the prior art, the utility model has the following advantages and effects: phantom microphone insertion detection function is realized without changing the interface mode, and abnormal sound problems do not occur at the moment of insertion. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 The circuit principle diagram of the utility model embodiment. DETAILED DESCRIPTION
[0016] The utility model will be further explained in detail in combination with the drawings and through embodiments, and the following embodiments are explanations of the utility model, and the utility model is not limited to the following embodiments.
[0017] The utility model embodiment comprises a power supply module, a detection module and a microphone connector DB1.
[0018] The 3-pin of the microphone connector DB1 is connected to the microphone negative pole MICN through the first audio coupling capacitor C1, and the 2-pin is connected to the microphone positive pole MICP through the second audio coupling capacitor C2.
[0019] The power supply module comprises a first power supply resistor R1, a second power supply resistor R2, a third power supply resistor R6, a fourth power supply resistor R7 and a power supply filter capacitor C3. One end of the third power supply resistor R6 is connected with the phantom power Phantom, and the other end is connected with one end of the fourth power supply resistor R7. The other end of the fourth power supply resistor R7 is connected with the 3-pin of the microphone connector DB1. One end of the first power supply resistor R1 is connected with the phantom power Phantom, and the other end is connected with one end of the second power supply resistor R2. The other end of the second power supply resistor R2 is connected with the 2-pin of the microphone connector DB1. One end of the power supply filter capacitor C3 is connected with the phantom power, and the other end is grounded. The first power supply resistor R1, the second power supply resistor R2, the third power supply resistor R6 and the fourth power supply resistor R7 play a role in voltage division. In the embodiment, the voltage P of the phantom power Phantom is 48V.
[0020] The detection module comprises a first detection resistor R3, a second detection resistor R4, a protection resistor R5, a detection filter capacitor C4 and a detection point M. One end of the first detection resistor R3 is connected at the connection of the first power supply resistor R1 and the second power supply resistor R2, and the other end is connected with one end of the second detection resistor R4. The other end of the second detection resistor R4 is grounded. One end of the detection point M is connected at the connection of the first detection resistor R3 and the second detection resistor R4 through the protection resistor R5, and the other end is connected at one end of the second detection resistor R4 grounded through one end of the detection filter capacitor C4. In this way, the detection point M is connected in parallel with the second detection resistor R4. The detection filter capacitor C4 plays a role in filtering out transient interference. The first detection resistor R3 and the second detection resistor R4 play a role in voltage division, otherwise the voltage is too high and the ADC acquisition circuit cannot receive it. The protection resistor R5 mainly functions to open the external interference and protect the chip of the ADC acquisition circuit.
[0021] The insertion detection principle of the utility information is as follows:
[0022] The ADC acquisition circuit judges whether the microphone is connected by collecting the voltage of the detection point M without connecting the microphone and after connecting the microphone. Specifically, the following is true:
[0023] 1. When the device is not connected with the microphone, the voltage of the detection point M is V1: (P / (R1+R3+R4))*R4.
[0024] 2. When the device is connected with the microphone, there is an additional load in the circuit, so the voltage is different. The current in the resistor R1 becomes I, and the voltage of the detection point M becomes V2: ((P-R1*I) / (R3+R4))*R4.
[0025] The voltage of the detection point M after inserting the microphone is V2, the voltage of the detection point M after not inserting the microphone is V1, according to the voltage taking a fluctuation range such as + / - 5%, the state of inserting the microphone and not inserting the microphone can be distinguished, the voltage of the detection point M is sent to the ADC collection circuit of the rear CPU, whether the microphone is inserted is judged according to the collected voltage, the rear audio output circuit is not started when the microphone is not inserted, when the microphone is detected, the audio output can be started after delaying 1 second and the like circuit is stable, so that the abnormal sound problem in the inserting moment will not appear.
[0026] In addition, it should be noted that the specific embodiments described in the specification, the shape of the zero, the components, the name taken, etc. can be different, the above described in the specification is only an example of the structure of the utility model. Any equivalent changes or simple changes made according to the structure, features and principles described in the utility model patent concept are included in the protection scope of the utility model patent.
Claims
1. A phantom microphone insertion detection circuit, comprising a power supply module and a microphone connector; the power supply module comprises a first power supply resistor and a second power supply resistor, one end of the first power supply resistor is connected with a phantom power supply, the other end is connected with one end of the second power supply resistor, the other end of the second power supply resistor is connected with the microphone connector; characterized in that: The detection module comprises a first detection resistor, a second detection resistor and a detection point; One end of the first detection resistor is connected to the connection between the first power supply resistor and the second power supply resistor, and the other end is connected to one end of the second detection resistor, and the other end of the second detection resistor is grounded. The detection point is connected in parallel with the second detection resistor.
2. The phantom microphone plug-in detection circuit of claim 1, wherein: The detection module further comprises a protection resistor, and one end of the detection point is connected to the connection between the first detection resistor and the second detection resistor through the protection resistor.
3. The phantom microphone plug-in detection circuit of claim 1, wherein: The detection module further comprises a detection filter capacitor, and the other end of the detection point is connected to one end of the second detection resistor through the detection filter capacitor.
4. The phantom microphone plug-in detection circuit of claim 1, wherein: The power supply module further comprises a power supply filter capacitor, one end of the power supply filter capacitor is connected to the phantom power supply, and the other end is grounded.
5. The phantom microphone plug-in detection circuit of claim 1, wherein: The 3-pin of the microphone connector is connected to the negative electrode of the microphone through the first audio coupling capacitor, and the 2-pin is connected to the positive electrode of the microphone through the second audio coupling capacitor.
6. The phantom microphone plug-in detection circuit of claim 5, wherein: The other end of the second power supply resistor is connected to the 2-pin of the microphone connector.
7. The phantom microphone plug-in detection circuit of claim 5, wherein: The power supply module further comprises a third power supply resistor and a fourth power supply resistor; One end of the third power supply resistor is connected to the phantom power supply, the other end is connected to one end of the fourth power supply resistor, and the other end of the fourth power supply resistor is connected to the microphone connector.
8. The phantom microphone plug-in detection circuit of claim 7, wherein: The other end of the fourth power supply resistor is connected to the 3-pin of the microphone connector.