| 摘要 |
A detector on a wire lead machine includes a pair of contacts biased into a normally closed position. The wire is fed between the contacts, keeping the contacts open, and the insulation on the wire prevents electrical conductivity between the contacts. If the wire runs out, the contacts close to shut off the machine. Additionally, a splice on the wire establishes an electrical path between the contacts and, again, the machine is shut off. The detector includes a detection circuit which generates a control signal. In the event a splice is passing through the contacts, the detection circuit generates a control signal having a relatively short time duration (as for example, 100 microseconds) and holds the signal for a sufficient time period (as for example, 500 milliseconds). This allows a suitable control means (which may include a microprocessor) to shut off the machine because of either wire runout or a splice on the wire, thereby preventing serious damage to the machine and maintaining productivity.
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