Fault alarm for pharmaceutical stamping machine - uses window cut in plate and passing between two opto-couplers to measure return time for comparison with set time

摘要

The alarm is actuated if imminent malfunction of the stamping machine is detected by the return time of stamping matrix being in excess of a preset time. The transition time is measured from the motion of the ejection rod, which has a window cut into a metal plate, the window ends passing through two infra-red opto-couplers. An electronic monostable circuit provides the reference time which is compared with the measured time. If a discrepancy is detected a visible alarm is activated and the machine shut-down.