摘要 |
<p>The spark erosion circuit adjusts scanning ratio, pulse frequency and intensity of the pulses applied to the erosion gap. It has a pulse emitter unit and a discharge circuit. Transistors in the discharge circuit direct the current to the gap in synchronism with the signals from the emitter unit, and the discharge circuit has ignition and working sections. In the current circuit between voltage source and gap (3) are transistors (2a, 2b) driven by the emitter unit (1). Some of these act as a switch, opening and closing the ignition section, and others as an amplifier, controlling the current in the working section. The emitter unit can be multi-channel, generating pulses of different form and duration in each channel. In the emitter branch of the amplifier transistors there can be negative feedback resistances (7) stabilising the output current.</p> |