Magnetic chuck control system
AssigneeSemi-Controls, Inc.
InventorsDaniel P. Bacchiere, Stanley F. Polinski
Life of this patent
Estimating the term…
Abstract
A magnetic chuck control system employing solid state circuitry including a power output circuit adapted to apply a DC voltage to an object such as a magnetic chuck or the like so as to magnetize the same. The power output circuit employs a triac reversing circuit and is interfaced with a digital control circuit and a digital-to-analog converter circuit so as to apply alternating polarity voltage signals of successively reduced magnitude to the chuck during a demagnetizing operation. All high voltage is confined to the power output circuit so as to provide significant safety protection to the operator.
Claims20
A system for magnetizing and demagnetizing a magnetizable object, comprising, in combination,
- a DC power supply,
- a power output circuit operatively connected to said DC power supply and a magnetizable object and adapted to apply DC voltage signals to the object in a manner to magnetize the object, said output circuit including a reversing circuit enabling reversing of the polarity of said DC voltage signals during demagnetizing, said reversing circuit defining a pair of input terminals connected in circuit with said DC power supply and a pair of output terminals connected to the object, bidirectional current control means selectively connected between said pairs of terminals so as to enable selective directional current flow through the object,
- a digital control circuit operatively associated with said current control means and operative to effect predetermined sequential conditioning of said bidirectional current control means so as to enable current flow through the object in alternating directions,
- a digital-to-analog converter circuit cooperative with said digital control circuit and adapted to produce successive output voltage signals of predetermined decreasing magnitude in direct relation to said predetermined conditioning of said bidirectional control means,
- and means connected in circuit between said DC power supply and said reversing circuit and being responsive to said successive output signals to apply successively decreasing DC voltage signals to the object, said digital control circuit being adapted to control said bidirectional current control means so that said successively decreasing DC voltage signals applied to the object are of alternating polarity.
A system for magnetizing and demagnetizing a magnetizable object, comprising, in combination,
- a first DC power supply,
- a second DC power supply adapted to provide a humanly harmless DC voltage signal
- a power output circuit operatively connected to said first DC power supply and a magnetizable object and adapted to apply DC voltage signals to the object in a manner to magnetize the object, said output circuit including a reversing circuit enabling reversing of the polarity of said DC voltage signals during demagnetizing, said reversing circuit defining a pair of input terminals connected in circuit with said DC power supply and a pair of output terminals connected to the object, bidirectional current control means selectively connected between said pairs of terminals so as to enable selective directional current flow through the object,
- a control circuit operatively connected to said second DC power supply and associated with said current control means in a manner to effect predetermined sequential conditioning of said bidirectional current control means so as to enable current flow through the object in alternating directions,
- additional circuit means connected to said second DC power supply and cooperative with said control circuit to produce successive ouput voltage signals of predetermined decreasing magnitude in direct relation to said predetermined conditioning of said bidirectional control means,
- means connected in circuit between said first DC power supply and said reversing circuit and being responsive to said successive output signals from said control circuit to apply successively decreasing DC voltage signals to the object, said control circuit being adapted to control said bidirectional current control means so that said successively decreasing DC voltage signals applied to the object are of alternating polarity,
- and means isolating said power output circuit from said control circuit and said additional circuit means so that said control circuit and additional circuit means are isolated from any fault currents in said power output circuit.
Dependencies are inferred from the claim text.