Sound operated control device

• US 4,215,241 A
• Filed: 10/16/1978
• Issued: 07/29/1980
• Est. Priority Date: 10/16/1978
• Status: Expired due to Term

• Current Assignee: Frank L. Eppenger
• Original Assignee: Frank L. Eppenger
• Inventors: Pinkney, Harry D. Jr.
• Primary Examiner(s): Hecker, Stuart N.
• Assistant Examiner(s): Popek, Joseph A.
• Application Number:
  US05/951,341
• Time in Patent Office: 652 Days
• Field of Search: 179/1 VC, 179/1 VL, 179/1 SW, 179/1 P, 179/1 HF, 179/81 B, 179/100.1 VC, 325/473, 325/475, 325/474, 325/476
• US Class Current: 367/197
• CPC Class Codes: A61G 12/00 Accommodation for nursing, e.g. in hospitals, not covered by groups A61G1/00 - A61G11/00, e.g. trolleys for transport of medicaments or food service or tea-tables, trolleys or wagons A47B31/00; Prescription lists
• CPC Class Codes: A61G 2203/70 with special adaptations, e.g. for safety or comfort
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

Two microphones, with at least one being directional and sensitive to different sound, are utilized in conjuction with a comparator circuit and a switching circuit to control electrically energized equipment such as alarm systems, machinery, safety devices and the like. The comparator circuit rectifies the output from each of the microphone amplifiers into either a positive or negative voltage, respectively. The switching circuit is set to pass current only when the voltage from the selected directional microphone exceeds the other microphone voltage by a predetermined value.

Claims

1. A sound-operated electrical control device adapted to receive predetermined sounds to activate switching means connected to electrical auxillary equipment upon receipt of predetermined sounds comprising:

a first circuit having first receptor means to receive a predetermined sound and generate a corresponding first electrical signal which is classified to a first polarity with first polarizing means; and

,

a second circuit in parallel with said first circuit having second receptor means to receive ambient sound and generate a corresponding second electrical signal which is classified to a second polarity with second polarizing means; and

,

switching means interconnecting said first and second circuits allowing either one or the other of said first and second signals to pass and activate the auxillary equipment, said first and second polarizing means comprising oppositely-poled diodes.

2. The device of claim 1 wherein said first receptor means comprises a microphone directed toward the predetermined sounds, and said second receptor means comprises a microphone directed directed away from the predetermined sounds.

3. The device of claim 1 wherein said first and second circuits each include audio amplifier means to amplify each of said corresponding electrical signals prior to being classified with said first and second polarizing means.

4. The device of claim 3 wherein said first and second circuits each include a preamplifier means located in each of said circuits after said receptor means, and further including volume control components located in each of said circuits after the preamplifier means.

5. The device of claim 1 wherein said switching means includes an electrical switching component having an entrance means with a threshold voltage which must be exceeded before a selected signal will be transmitted.

6. The device of claim 5 wherein the switching component comprises a silicon controlled rectifier.

7. A sound-operated electrical control system comprising:

first and second microphone means connected to corresponding parallel first and second audio channels, each of said channels having a means to rectify signals from said microphone means into respective negative and positive signals, said means for rectifying the signals include a diode in said first channel which passes only a positive signal and a diode in said second channel which passes only a negative signal; and

,

switch means connecting said channels and having a switch component adapted to pass only one or the other of said negative or positive signals to auxillary equipment.

8. The system of claim 7 wherein said first microphone means is adapted to receive sound from a predetermined source and said second microphone means is adapated to receive ambient sound.

9. The system of claim 8 wherein each of said audio channels includes means to amplify electrical signals from the microphone means.

10. The system of claim 9 wherein said switch component includes an SCR having a gate that passes only positive signals of a predetermined voltage to said auxillary equipment.