I have a question about how the circuit of TV display works. Does current flow through the gate lines (horizontal lines)?

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  • \$\begingroup\$ How else would a row be selected? \$\endgroup\$ – Ignacio Vazquez-Abrams May 15 '18 at 11:51
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    \$\begingroup\$ @Ignacio, without current flow. Electrostatically, using the field effect of the field effect transistors the OP shows. There is a tiny leakage current but it's the presence of voltage, not a current. \$\endgroup\$ – TonyM May 15 '18 at 12:24

The FET gates loading the horizontal select lines effectively detect the presence of a voltage, drawing only a leakage current. So the lines do pass current but not a signalling current. With many thousands of FETs on the line, this will add up.

Each gate also presents a capacitance to its horizontal select line and this needs to be charged up or discharged when the line transitions low-high or high-low. So a higher current will be drawn/sunk until this capacitance is charged/discharged on a transition.

  • \$\begingroup\$ Thank you for your answer. If the left end of each gate line is connected to a scan voltage driver, does the right end have to be connected to somewhere? \$\endgroup\$ – pothny3 May 15 '18 at 12:46

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