A former police officer accused of attacking his former wife with a makeshift electrical device and strangling her with an electrical cord has had a charge against him dropped.

Mark Leslie Anderson is on trial in the ACT Supreme Court for threatening to kill another person, burglary, assault occasioning actual bodily harm and breaching a protection order.

He was also on trial for charges relating to the use of an offensive weapon, until Chief Justice Terence Higgins dropped the charge on Thursday.

Anderson was accused of assaulting his former wife, Catherine Green, with a weapon, similar to a Taser, which he had constructed using an electrical cord and metal at a home in Farrer in June 2010.

When the device failed to deliver a shock he was alleged to have used the cord to choke her and his hand to try to suffocate her.

Chief Justice Higgins dismissed the offensive weapon charge as there was no evidence the cord had been connected to a power source. The judge said the cord was not a weapon unless it could produce an electrical current, therefore the charge had failed.

''It's not an offensive weapon likely to endanger human life or cause grievous bodily harm,'' the judge said.

It is the second charge to be dropped against Anderson, after a count of attempted murder was abandoned before the trial began.

The Crown on Thursday closed its case in the judge-only trial.

Anderson was called to give evidence by the defence barrister Bernard Collaery on Thursday.

The court heard the defendant had given up on reconciling the marriage at the time of the alleged incident and had started another relationship.

The accused man said he had been a ''house dad'' since he left the police force after he was stabbed in the line of duty in 2004.

He confirmed the couple split in 2009 and a domestic violence order had been issued in May the following year.

Anderson admitted he had gone to the house on the day of the incident, but said it was at the request of Ms Green, who had asked him to fix wiring in a disused bathroom.

The court heard the accused man had initially refused because he did not want to breach the court order, but agreed when Ms Green said she would be at work.

Anderson said Ms Green had frequently asked him to work on items after the split.

He said he often refused requests but consented at that time as the wiring was the result of his unfinished renovation and he was worried it would endanger his children.

He will resume his testimony when the trial continues on Friday.