A defendant may be permitted at his election to proceed in the trial of his case without the assistance of counsel only after the trial judge makes thorough inquiry and is satisfied that the defendant:
(1) Has been clearly advised of his right to the assistance of counsel, including his right to the assignment of counsel when he is so entitled;
(2) Understands and appreciates the consequences of this decision; and
(3) Comprehends the nature of the charges and proceedings and the range of permissible punishments.