Patent ID: 11881849
Assignee: LITTELFUSE, INC.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A relay circuit, comprising:
a solid state relay switch, coupled to an external voltage line and to a charging capacitor;
a solid state relay control circuit, coupled between the charging capacitor and the solid state relay switch, the solid state relay control circuit arranged to:
turn the solid state relay switch to an OFF state when a capacitor voltage of the charging capacitor falls below a low threshold value; and
change the solid state relay switch from the OFF state to an ON state when the capacitor voltage increases above a high threshold value;
the solid state relay control circuit comprising:
a voltage divider circuit, coupled to receive the capacitor voltage of the charging capacitor; and
a comparator to output a logic signal in a HIGH or LOW state based upon a level of a voltage signal received from the voltage divider circuit;

the voltage divider circuit comprising:
a first control switch, coupled to a first voltage stage of the voltage divider circuit:
a second control switch, coupled to a second voltage stage of the voltage divider circuit;
a control voltage line, coupled between the first control switch, the second control switch, and a first input to the comparator; and
a reference voltage source coupled to output a reference voltage to a second input of the comparator; and

an AND gate, having a first input coupled to an output of the comparator, and a second input coupled to receive an ENABLE signal.