摘要 |
In a matrix array for the supply of an electrographic stylus writing apparatus, a plurality of styli are driven by short pulses through R/C networks. The styli are divided into subgroups and parallel capacitors connect the styli of each subgroup to a high voltage switch which is responsive to a capacitor pulse driver. Each stylus is also driven through a resistive line which completes the R/C circuit. The resistive lines are connected in parallel for similar styli of each group to a resistor enable pulsing circuit and all resistive lines are connected via isolation diodes to a resistor reset means. In operation, a short pulse from the capacitor driver circuit is applied to all the capacitors of a single group and an enabling pulse is applied to a predetermined single resistive line of each group so that the combined, enabled R/C circuit for a single stylus within one of groups is activated. |