Robert Boschgmbh

Gerhard Gulich

Rolf Wohr

Helmut Martini

Rudi Meny

Roland Sauer

Edgar Bressert

Instead of monitoring a thermal deburring operation by reference to whether a certain high temperature is reached and thereby indicting whether a successful ignition in the deburring chamber has taken place at every step of operation of the chamber, a circuit responsive to the rate of change of temperature is used to recognize a successful operation, thus permitting faster operation of the apparatus. Such a circuit is also useful for rapid detection of a short circuit circuit in electrochemical apparatus utilizing heavy electrical currents and variable amounts. In the latter case a digital circuit for measuring the amount of change at equal intervals of time is particularly useful.

Detecting a rapid change of a critical physical condition

The high voltage between a rotary disk coating powder dispensing device and an electrically grounded article to be coated is maintained constant when the spacing between a spray disk at high potential and an article to be coated at ground potential is too great to permit a breakdown discharge, whereas at smaller spacings the current flowing as the result of transport of charged coating material is held constant, but when the spacing goes below a minimum value at which the energy stored in the disk device and in the wiring capacitance is sufficient to support a breakdown, the high-voltage supply is switched off, by short-circuiting the high-voltage transformer secondary winding. When the high-voltage supply is thus switched off, an acoustic or optical alarm is actuated to call attention to the necessity of restoring operation. The spacing between the article being coated and the disk device varies in operation of the coating process as a series of articles suspended on a conveyor are moved past the disk device by driving the conveyor.

Growing community of inventors

Stuttgart, Germany

Gerhard Gulich