Ultrasonic wave nebulizer driving circuit

• US 4,359,697 A
• Filed: 08/21/1981
• Issued: 11/16/1982
• Est. Priority Date: 08/03/1978
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: TDK Electronics (TDK Corporation)
• Inventors: Takahashi, Minoru
• Primary Examiner(s): Moore, David K.
• Application Number:
  US06/294,845
• Time in Patent Office: 452 Days
• Field of Search: 331/1 R, 331/26, 331/116 R, 331/116 M, 331/155, 331/139, 331/109, 310/316, 310/116, 310/311
• US Class Current: 331/116.00R
• CPC Class Codes: B05B 17/0607 generated by electrical means, e.g. piezoelectric transducers
• CPC Class Codes: B06B 1/0253 taken directly from the generator circuit
• CPC Class Codes: B06B 2201/55 Piezoelectric transducer
• CPC Class Codes: B06B 2201/77 Atomizers

Abstract

Positive feedback is applied from the piezo-electric vibrator in an ultrasonic nebulizer to the control electrode in the oscillator circuit for improved performance.

Claims

1. In an ultrasonic nebulizer driving circuit that includes an oscillator for generating a high frequency signal to energize a piezo-electric vibrator that generates ultrasonic waves, said oscillator including a control element having a control electrode, means including a bias resistor for supplying a biasing current to said control electrode, the improvement comprising a positive feedback circuit to feed back a part of said high frequency signal to said control electrode independent of said bias resistor to supplement said biasing current and concomitantly enable said bias resistor to be reduced in wattage.

2. A circuit as in claim 1, wherein said feedback circuit comprises a capacitive pickup and resistive divider network coupled to said vibrator to develop a high frequency signal corresponding to the signal applied to said vibrator.

3. A circuit as in claim 2, including a diode element for coupling said capacitive pickup and resistive divider network to said control electrode.

4. A circuit as in claim 3, wherein said control element is a transistor.

5. A circuit as in claim 4, wherein said control electrode is the base of said transistor.

6. A circuit as in claim 5, wherein said diode is poled so as to increase in a negative sense the potential of said base.

7. A circuit as in claim 6, wherein said vibrator is coupled to the base and emitter of said transistor.

8. A circuit as in claim 7, wherein said vibrator is transformer coupled to said base and emitter.

9. A circuit as in claim 1, wherein said piezo-electric vibrator constitutes one of the oscillation elements of said oscillator.