Voicecoil actuators are fast and reliable

Over the stroke range, the force delivered is virtually constant with a small variance of about 5% at the ends of the stroke. And, with very low electrical and mechanical time constants, fast operation is possible with speeds up to 2m/s and operating frequencies up to around 55Hz, depending on size, load and travel profile. The actuators operate almost silently and the stroke is free from cogging. Maintenance is not required as there is no commutation. The actuators are guided axially by low friction, Teflon-coated plain bearings and the electrical cabling to the coil is made from highly flexible, stranded interconnecting wires. Body diameters are between 30 and 90mm and strokes are from 5mm to 30mm. Forces generated by the actuators are in a controllable range of 0 to 32N with continuous duty. Peak forces with intermittent duty are up to 51N. The actuators can 'push' or 'pull' depending on the polarity, there is no hysteresis and the delivered force can be controlled proportional to current. The units are therefore ideal for pick-and-place in chip mounting for PC boards, switch testing, creation of controllable vibration, optical systems, precision packaging and high speed labelling. An alternative power supply through an enclosed flexible printed circuit foil has also been developed, which is currently undergoing trials. DP Pointers * Force delivered by the voicecoil actuator is virtually constant with a small variance of around 5% at the ends of the stroke * The units are near silent and are ideal for fast operation pick-and-place applications, with speeds up to 2m/s * The actuators can 'push' or 'pull' depending on the polarity, and the units are maintenance-free as they have no commutation