US 5,473,288 A · Oscillation circuit

Abstract

The oscillation circuit 30 has the two input terminals 32a and 32b connected to the piezoelectric elements 3a and 3b of vibrator 1. These input terminals 32a and 32b are connected to the two input terminals of the adder 36 via the buffers 34a and 34b. The output terminal of the adder 36 is connected to the inversion input terminal of the operational amplifier 44 used as a comparator and the input terminal of the control signal generator 46. The output terminal of the operational amplifier 44 is connected to the collector of the transistor 62 and the output terminal of the control signal generator 46 is connected to the base of the transistor 62. The emitter of the transistor 62 is connected to the output terminal 80 via the phase-shifting circuit 70. The output terminal 80 of the oscillation circuit 30 is connected to the piezoelectric element 3c of the vibrator 1.

Claims12

Dependent claims

An oscillation circuit comprising:

a comparator which receives a signal detected from a vibrator and shapes it to a square-wave signal with a constant amplitude,
a control signal generator which receives the detected signal from said vibrator, compares it with a reference voltage, and generates a control signal based on a difference between the reference voltage and the control signal,
a transistor whose collector receives the square-wave signal from said comparator and whose base receives the control signal from said control signal generator, and
a phase-shifting circuit whose input terminal is connected to an emitter of said transistor;
wherein an output signal of said phase-shifting circuit is used for driving said vibrator.

2 more elements

Dependencies are inferred from the claim text.

Oscillation circuit

Life of this patent

Oscillation circuit

Life of this patent

Abstract

Claims12