having a plurality of control members, e.g. keyboard

Full Title

Electronic switching or gating, i.e. not by contact-making and –breaking (gated amplifiers H03F3/72; switching arrangements for exchange systems using static devices H04Q3/52) > characterised by the way in which the control signals are generated > Switches controlled by moving an element forming part of the switch > using opto-electronic devices > having a plurality of control members, e.g. keyboard