Power supply having automatic frequency control for ultrasonic bonding
US4389601A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1980 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | Sep 8, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K20/10
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A power supply is provided for an electromechanical device of the type employing ultrasonic frequency vibratory energy for bonding materials. An automatic frequency control varies the output frequency of the power supply until the ratio of the maximum to minimum amplitudes of a standing wave produced in the mechanical vibratory member falls below a pre-set maximum. The frequency of the power supply is set by a voltage controlled variable frequency oscillator. A sweep generator produces a periodic voltage signal having a frequency substantially less than the frequency range of the voltage controlled oscillator. Means are provided for coupling the voltage signal from the sweep generator to the control input of the voltage controlled oscillator whenever the standing wave ratio exceeds a pre-set value, and for holding the last voltage signal received by the control input of the voltage controlled oscillator whenever the standing wave ratio is equal to or less than the pre-set value. Thus, the power supply frequency will be automatically varied to maintain the standing wave ratio below a pre-set value which is deemed to be an acceptable value for efficient transfer of power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.