Suspension of sentence of minor delinquents. Whenever a minor of either sex, under sixteen years of age at the date of the commission of a grave or less grave felony, is accused thereof, the court, after hearing the evidence in the proper proceedings, instead of pronouncing judgment of conviction, shall suspend all further proceedings and shall commit such minor to the custody or care of a public or private, benevolent or charitable institution, established under the law for the care, correction or education of orphaned, homeless, defective, and delinquent children, or to the custody or care of any other responsible person in any other place subject to visitation and supervision by the Director of Public Welfare or any of his agents or representatives, if there be any, or otherwise by the superintendent of public schools or his representatives, subject to such conditions as are prescribed hereinbelow until such minor shall have reached his majority or for such less period as the court may deem proper.