Electrical Contact Bounce and the Control Dynamics of Snap - Action Switch
نویسنده
چکیده
Experimental and theoretical studies are made of a typical snap-action rocker switch, to establish the wear mechanisms in the pivoting contact. The rocker switch, used extensive~ in consumer goods, operates in the medium duty current range, (1 30 Amps). Highspeed photographic studies have shown that the main cause of wear is arcing, occurri~ during separation and bounce at the pivot contacts. To reduce the bounce a computer-based mathematical model of the system dynamics is developed and opcimised; this results in recommended design changes. These changes are tested under tull current endurance conditions, and show significant improvements in wear. The model of the switch dynamics relates the mathematics of motion to the bounce occuring at the pivot contact, without the influence of current. ' To show the effect of current and arcing, an automatic test system is developed for the controlled testing of electrical contacts. The system has the ability to evaluate arc energy, bounc~ times, and contact resistance. The results presented detail the influence of d.c current on contact bounce time, and identify the Lmportance of the subsequent bounce time; which is defined for a single make operation, as the total duration of the bounces occurr·.,,J after the first bounce. To compare the erosion profiles of the switch and test system, the system is operated under full load current endurance conditions, to evaluate wear. This comparison shows tnat the wear in the real switch contacts is greater, as result of the additional contact movement of slip and rolling.
منابع مشابه
Second Order Sliding Mode Observer-Based Control for Uncertain Nonlinear MEMS Optical Switch
This paper studies theuncertain nonlinear dynamics of a MEMS optical switch addressing electrical, mechanical and optical subsystems. Recently, MEMS optical switch has had significant merits in reliability, control voltage requirements and power consumption. However, an inherent weakness in designing control for such systems is unavailability of switch position information at all times due to t...
متن کاملOptimal Sensorless Four Switch Direct Power Control of BLDC Motor
Brushless DC (BLDC) motors are used in a wide range of applications due to their high efficiency and high power density. In this paper, sensorless four-switch direct power control (DPC) method with the sector to sector commutations ripple minimization for BLDC motor control is proposed. The main features of the proposed DPC method are: (1) fast dynamic response (2) easy implementation (3) use o...
متن کاملSensorless Model Predictive Force Control with a Novel Weight Coefficients for 3-Phase 4-Switch Inverter Fed Linear Induction Motor Drives
The sensorless model predictive force control (SMPFC) is a strong method for controlling the drives of three-phase 4(6)-switch inverter linear induction motors. This kind of inverter can be employed for fault tolerant control in order to solve the problem of open/short circuit in 6-switch inverters (B6). This paper proposed a method for the SMPFC of a linear induction motor (LIM) with a 4-switc...
متن کاملRobust Lyapunov-based Control of MEMS Optical Switches
In this paper, a robust PID control scheme is proposed for Micro-Electro-Mechanical-Systems (MEMS) optical switches. The proposed approach is designed in a way which solves two challenging and important problems. The first one is successful reference tracking and the second is mitigating the system nonlinearities. The overall system composed of nonlinear MEMS dynamics and the PID controller is ...
متن کاملRobust Lyapunov-based Control of MEMS Optical Switches
In this paper, a robust PID control scheme is proposed for Micro-Electro-Mechanical-Systems (MEMS) optical switches. The proposed approach is designed in a way which solves two challenging and important problems. The first one is successful reference tracking and the second is mitigating the system nonlinearities. The overall system composed of nonlinear MEMS dynamics and the PID controller is ...
متن کامل