| 摘要 |
<p>Driving circuit for a pocket calculator computing circuit uses a transistor switch. The transistor (T1) short-circuits the terminals of an add key (S+ with its emitter-collector path, and its base recieves the output signal from a sawtooth generator. Pref. the sawtooth waveform generator contains an RC element with its capacitor connected in parallel to a thyristor (Th). The RC element itself comprises a capacitor in series with a fixed resistor (R1) and a variable trimming resistor (R2).</p> |
