To understand why John Proctor calls for the judges after speaking to his wife, one must have insight into the circumstances in which the characters find themselves at this juncture.
The Proctors have been incarcerated for about three months at this point, and both have stubbornly refused to confess. Reverend Parris has expressed fear that the townspeople are in a rebellious mood. He also states that his life has been threatened. He believes that a stay of execution for those such as John, Elizabeth, Rebecca, and Martha Corey would be the ideal since they can be urged to confess. Because they are much respected and admired in the village, their admissions of guilt will prevent a rebellion.
Judge Danforth stubbornly refuses to postpone their hangings but does later soften to the idea of having Elizabeth speak to her husband about making a confession. Elizabeth is pregnant, and John has not seen her for three months. It is believed that these factors and her urging might persuade him.
Elizabeth is brought forth and Reverend Hale pleads with her to speak to John. He tells her, in part:
Life, woman, life is God’s most precious gift; no principle, however glorious, may justify the taking of it.
Reverend Hale knows that John is innocent but insists that he must lie in order to save his life. Elizabeth refuses, however, to persuade him, and is not convinced. It is only when the recalcitrant Judge Danforth asks that she be taken back to her cell that she relents and asks to speak to her husband. John is then brought from his cell, and he and Elizabeth are left alone to speak.
During their anguished discussion, John tells Elizabeth that he wants to confess. He begs her to forgive him. She informs him that Giles Corey was pressed to death without confessing and that Rebecca Nurse and Martha Corey have also refused to admit their crimes. This knowledge adds to her husband's deep distress. She asks his forgiveness for having kept "a cold house" that made him turn from her. Elizabeth pleads with him to do as he wishes and not allow anyone to judge him. She tells him that she "never knew such goodness in the world."
John's mind is finally made up. When Judge Hathorne appears John twice tells him, "I will have my life." The judge is overjoyed that John has decided to confess and goes to summon the others. John's torment is, however, still patently obvious because he repeatedly asks Elizabeth if she would confess to such a lie. She cannot answer him and only says that she cannot judge him. John is determined to follow through with his decision and cries out:
It is evil. Good, then - it is evil, and I do it!
At this point, all the other officials of the court arrive. Judge Danforth, with great relief, compliments John on having made a wise decision by telling him that he will be "blessed in heaven." It is ironic, though, that John later tears up his signed confession when he realizes that the document is to be put up on the church door as proof of his capitulation.
In the conversation you are talking about John Proctor has been condemned to death for witchcraft. He is talking to his wife Elizabeth about whether he should give a false confession so as to avoid being executed.
After they finish talking, John decides that he will confess. Once he has decided, he tells Hathorn and Hathorn is the one who calls for the other judges.
As it turns out, John confesses, but then thinks better of it and rips up his confession after thinking about what confessing means and after talking briefly with Rebecca Nurse. As the play ends, he is being executed.
He calls for the judges so he can "confess" (lie) to having compacted with the devil because he finally has Elizabeth's forgiveness and wishes to live with her.