Patent · US Expired

Circuit arrangement for contactless switchover of operation parameters of an electrically driven tool

US5399959A · kind A · utility

1Cited by

4References

4Claims

0Family size

Assignee

Hilti Aktiengesellschaft · LI

Inventors

Egon Konigbauer · Olching, DE
Wolfgang Millauer · Munich, DE

Key dates

Filing date	Nov 16, 1992
Grant date	Mar 21, 1995
Priority date	—
Expiry date	Nov 16, 2012

Classification

Technology area (CPC H)Electricity
CPC primaryH02P25/14
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A circuit arrangement is disclosed for a non-contacting switch-over of operational parameters in an electrically driven tool, for instance, a hammer drill, which are determined by a voltage divider ratio with reference to a stabilized supply source. The voltage divider ratio is obtained by selective parallel switching of an additional ohmic resistor by means of a Hall switch, whose current supply is supplied by a Zener diode which lies in series with the stabilized supply source. The circuit of the Hall switch puts the low point of the additional resistor, connected through a diode, to the low point of the voltage divider, in parallel with the partial resistor of the voltage divider, through a drop resistance. The switching arrangement or circuit arrangement has the advantage that the current supply of an RPM control unit is only slightly additionally loaded or increased.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.