| 摘要 |
<p>The circuit provides the reversible current flow required for a silver iodide electrolytic display cell by use of a push-pull output stage made up (in integrated circuit form) from MOSFET transistors. Voltage fluctuations over the electrolytic cell, arising from the voltage drop due to the channel resistance of the MOSFET transistors, are compensated by a differential amplifier driving the push pull output transistors. One side of the differential amplifier (18) is connected to the centre point of the push-pull output pair (30,32) and thus to one electrode of the electrolytic display cell (10). The other side of the differential amplifier is switched (26,28) to one of two potentials, activating one or other of the output transistors and causing current to flow in the cell in one direction or the other and thus to darken or clear the cell. Variation of the cell voltage causes compensating variation in the differential amplifier output, thus tending to maintain constant current in the cell.</p> |
