US 5,671,115 A · Circuit arrangement for driving a contactor

Abstract

Electronic driving components sized to drive contactors of a determined power class are generally used. The object of the invention is to create a process and circuitry which allows contactors of different power classes to be driven by a single driving component. The user selects on a scale the switching position corresponding to the contactor to be driven. A reference voltage proportional to the magnitude of the starting current of the respective contactor is thus selected. An automatic regulation keeps constant the starting current during the starting time of the contactor. For that purpose, a measurement voltage proportional to the magnitude of the starting system and dropping across a measuring resistor is supplied to a first input of a comparator, a reference voltage which may be selected by a coding switch (6) being applied to the second input of the comparator. The output of the comparator co-operates with a switching element which switches the starting current. This circuitry may be mounted upstream of existing contactors, in particular on a top hat rail.

Claims14

Dependent claims

A circuit arrangement for driving a contactor, comprising:

a controllable switching element;
a contactor coil;
and
a measuring resistor coupled between and in series with said controllable switching element and said contactor coil;
a control voltage source coupled in series with said controllable switching element, contactor coil, and measuring resistor;
a regulation device coupled to said switching element such that said contactor is supplied with a starting current having a constant average value and said regulation device is coupled to a switchover device, said switchover device selecting from a plurality of different starting currents corresponding to power classes of different contactors;
a free-wheeling branch coupled to said contactor coil, said free-wheeling branch including a free-wheeling diode coupled to a free-wheeling switching element;
and
a first monoflop coupled to and driving said free-wheeling switching element via a free-wheeling optocoupler and a zener diode stabilizer, such that switching times of said first monoflop are capable of being adjusted via an RC divider circuit coupled to said first monoflop, said RC divider circuit having an ohmic component that is capable of being selected via a coding switch.

6 more elements

Dependencies are inferred from the claim text.

Circuit arrangement for driving a contactor

Life of this patent

Circuit arrangement for driving a contactor

Life of this patent

Abstract

Claims14