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Electronic Device Interface With Low Level, Low Impedance Microphone For Aviation Headsets
Abstract: Abstract: Electronic device(fig-2) interface with low level, low impedance microphone for aviation headsets is disclosed that generates distortion less audio signal through embodiments comprising, an impedance network (5) to match the microphone impedance built with passive R-L-C network, a Channel Isolator (6) that acts signal isolator to switch the mike signal received from the said impedance network (5) in two paths for redundancy feature(active-12 & redundant-13) and a low noise Instrumentation amplifier (7) to linearly amplify the low level microphone signals switched from the said Channel Isolator (6) through a single gain resistor. The said R-L-C network also prevents the Low noise instrumentation amplifier from oscillations incase the microphone impedance goes below 10 ohms. In a desired configuration the distortion factor obtained from the said electronic device (fig-2) is 0.01%.
Notices, Deadlines & Correspondence
Patent Information
Applicants
HINDUSTAN AERONAUTICS LIMITED
Inventors
1. CHORAGUDI ASHOK KUMAR
2. MULPURU KARTHIKEYA PAVAN KUMAR
Specification
We claim:
1. An electronic device interface with a low level, low impedance microphone (4) comprising:
- an impedance network (5) to match the microphone(3) impedance,
- a Channel Isolator (6) to switch the mike signal received from the said impedance network (5) in two paths for redundancy feature, and
- a low noise Instrumentation amplifier (7) to linearly amplify the low level microphone signals switched from the said Channel Isolator (6).
2. The impedance network (5) as claimed in claim 1 is built with two Ferrite beads (L), a Capacitor (C) and a resistor (R) to form R-L-C network that matches the impedance of the microphone.
3. The impedance network (5) as claimed in claim 1 with the said R-L-C network forms a type-II low pass filter that can filter the high frequency noise picked up by microphone(4) or the interconnecting cables(8).
4. The R-L-C network as per claim 2 forms a input stabilization network for the said low noise instrumentation amplifier (7) to prevent it from oscillations.
5. The Channel Isolator (6) as claimed in claim 1 provides on-resistance of 80 ohms in power ON condition and configure itself clearly open circuit with a leakage current of upto 5nA in power OFF condition.
6. The low noise instrumentation amplifier (7) as claimed in claim 1 has gain factor from minimum 2 to maximum 1000 i.e., 6 dB to 60dB w.r.t Input signal that can be adjusted through a single gain resistor that has a range minimum 10 ohms to maximum 6K ohms.
7. The low noise instrumentation amplifier (7) as claimed in claim 1 generates an unbalanced output signal(9) as per the said gain factorsby means of selective gain resistors.
8. The unbalanced output (9) from the said low noise instrumentation amplifier (7) has distortion factor of less than 0.01%.
Documents
Application Documents
| # | Name | Date |
|---|---|---|
| 1 | 202241054536-Form5_As Filed_23-09-2022.pdf | 2022-09-23 |
| 2 | 202241054536-Form3_As Filed_23-09-2022.pdf | 2022-09-23 |
| 3 | 202241054536-Form2 Title Page_Complete_23-09-2022.pdf | 2022-09-23 |
| 4 | 202241054536-Form1_As Filed_23-09-2022.pdf | 2022-09-23 |
| 5 | 202241054536-Form18_Examination Request_23-09-2022.pdf | 2022-09-23 |
| 6 | 202241054536-Drawings_As Filed_23-09-2022.pdf | 2022-09-23 |
| 7 | 202241054536-Description Complete_As Filed_23-09-2022.pdf | 2022-09-23 |
| 8 | 202241054536-Correspondence_As Filed_23-09-2022.pdf | 2022-09-23 |
| 9 | 202241054536-Claims_As Filed_23-09-2022.pdf | 2022-09-23 |
| 10 | 202241054536-Authorization Certificate_As Filed_23-09-2022.pdf | 2022-09-23 |
| 11 | 202241054536-Abstract_As Filed_23-09-2022.pdf | 2022-09-23 |
| 12 | 202241054536-FER.pdf | 2025-06-23 |
Search Strategy
| 1 | 202241054536_SearchStrategyNew_E_SearchHistoryE_17-06-2025.pdf |