Actuator Design of a New AC PM Contactor with Energy-Saving and Noise-Free Characteristics
Developments in power electronic switches and lowcost actuator based on an electronic control module (ECM) have made it possible to design and implement modern control strategies for a new AC permanent magnet (PM) contactor. Such an attempt has made in this work for a colenoid actuator controlling the AC PM contactor. Certain important issues in design including the making signal generator and its amplifier, breaking signal generator and its amplifier, exciting coils, and a voltage regulator have been resolved. The proposed scheme is validated through extensive numerical simulations and a laboratory scale implementation.
Comparison evaluation for permanent magnet arrangements of AC permanent magnet contactor
Alternating current (AC) permanent magnet (PM) contactor is a new type of contactor, which coil does not consume energy during its working course. This paper proposes a new structure contactor and analyzes magnet field distributions of PM arrangements both on stator and on armature based on finite element method. The computed results of two arrangements are almost the same for making course, but for breaking course, the arrangement of PM on armature has much more breaking inertia than that of PM on stator for certain supplied voltage. Experiments of displacement versus time verify theoretical prediction.
Influence of filler addition, storage medium and evaluation time on biaxial flexure strength and modulus of adhesive systems
Abstract Objective. This study evaluated the effects of filler addition, storage medium and time on biaxial flexural strength and flexural modulus of six adhesive systems. Materials and methods. The adhesives were either unfilled resins: Single Bond, Prime&Bond 2.1 and One-Step; or filled resins: Single Bond Plus, Prime&Bond NT and One-Step Plus. Resin discs of each product (0.5 mm thick × 6.0 mm diameter) were prepared using silicon molds (n = 10). The discs were stored dry, in water, mineral oil or ethanol for 1 week or 3 months before biaxial flexural testing. Data were statistically analyzed by 3-way ANOVA and Tukey's post-hoc test (α = 0.05). The specimens were tested in a universal testing machine at 1.27 mm/min until failure occurred. Results. In general, the storage in ethanol led to significantly lower flexural strength and flexural modulus values than the other storage conditions for all adhesives in both storage periods. Filler addition increased flexural strength and flexural modulus for Prime&Bond NT, when it was stored dry or in water for 1 week. For Single Bond Plus, the filler addition resulted in higher flexural modulus, when it was stored for 1 week in oil and in ethanol. No significant differences in flexural modulus were observed between One-Step and One-Step Plus in any storage medium. Conclusions. Results suggested that filler addition does not necessarily have to increase the flexural strength and flexural modulus. Ethanol and oil storages tended to yield opposite effects.