Driving circuit for driving a piezoelectric vibrator
US4939402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1989 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | May 19, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B2201/55
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A single transistor type driving circuit for a piezoelectric vibrator. The driving circuit includes a transformer having a primary winding and a secondary winding, a single switching transistor connected in series with the primary winding, the piezoelectric vibrator being connected with the secondary winding, a transistor driving circuit for applying driving current to the switching transistor so that the switching transistor is alternately turned on and off to thereby drive the vibrator at or in the vicinity of a resonating frequency of the vibrator. A coil is connected in series with the piezoelectric vibrator so that current and voltage of sinusoidal form are applied to the vibrator. A phase comparator compares phase of the sinusoidal current at the piezoelectric vibrator with phase of voltage at the secondary winding of the transformer to produce a phase difference signal, and the frequency of the driving current is controlled in accordance with the phase difference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.