Electrical contact arrangements

Claim 1

AN ELECTRICAL CONTROL ARRANGEMENT COMPRISING OSCILLATOR MEANS, CONTROL CONDITION SIGNAL MEANS OPERATIVELY CONNECTED TO THE OSCILLATOR MEANS TO PROVIDE A SIGNAL FOR CONTROLLING THE OSCILLATOR MEANS ACCORDING TO PREDETERMINED CONDITIONS, AND SEMICONDUCTOR CONTROLLED RECTIFIER MEANS INCLUDING AT LEAST TWO SEMICONDUCTOR CONTROLLED RECTIFIERS SETTABLE TO CONDUCTIVE OR NONCONDUCTIVE CONDITIONS, DEPENDENT ON WHETHER SAID OSCILLATOR MEANS IS OR IS NOT CAUSED TO OSCILLATE BY SAID CONTROLLING CONDITION WHEREIN THE OSCILLATOR MEANS INCLUDES TWO OSCILLATORS CONTROLLABLE BY SAID CONTROL CONDITION, SAID CONTROL CONDITION RENDERING THE FIRST OF OSCILLATE WHEN IT HAS ONE POLARITY AND THE SECOND OSCILLATOR OPERABLE WHEN IT HAS ANOTHER POLARITY, THE TWO SEMICONDUCTOR CONTROLLED RECTIFIERS HAVING A COMMON OUTPUT TERMINAL AND OPERATIVELY CONNECTED TO TWO VOLTAGE SOURCES, THE SEMICONDUCTOR CONTROLLED RECTIFIERS CONDUCTIVE OR NONCONDUCTIVE CONDITION BEING CONTROLLED BY THE OSCILLATING OR NONOSCILLATING CONDITION OF THE SAID FIRST AND SECOND OSCILLATORS FO THAT WHEN SAID FIRST SEMICONDUCTOR CONTROLLED RECTIFIER IS IN ITS CONDUCTIVE CONDITION IT CONNECTS A SOURCE OF VOLTAGE OF ONE POLARITY TO AN OUTPUT TERMINAL AND IN WHICH WHEN SAID SECOND SEMICONDUCTOR CONTROLLED RECTIFIER IS IN ITS CONDUCTIVE CONDITION IT CONNECTS A SOURCE OF THE OTHER POLARITY OF SAID OUTPUT TERMINAL.