Mechanical Characteristics and Electrical Characteristics of Vandal-Resistant Switches
– Vandal-resistant switches are constructed of durable materials such as stainless steel or polycarbonate plastic.
– The housing for these switches is often thick and secured with security screws.
– Flush-mounting is used to minimize the height of buttons, making it difficult to pry them out.
– Some vandal-resistant switches are potted to make them waterproof.
– The International Electrotechnical Commission has established standards for protection against liquids and dust.
– Vandal-resistant switches are often low-voltage, low-current signal types.
– Mechanical switches have gold-plated contacts that do not corrode.
– Some switches can handle higher currents and have silver or silver-plated contacts.
– Many vandal-resistant switches are momentary types, only activating while being depressed.
– Piezoelectric switches provide a pulse signal when pressure is applied.
Hidden and Locked Switches
– Some equipment has switches hidden behind locked covers or panels.
– Tamper-resistant designs make it harder for unauthorized users to activate or change settings.
– In some cases, transparent plexiglass covers are used to allow verification of settings while preventing tampering.
– Screwed-on door-covered switches are used on public address equipment and children’s toys.
– These hidden switches provide control over specific settings or functions.
– Vandal-resistant switches with key or tool operation prevent accidental or casual use.
– Some switches are built into keyed lock mechanisms to prevent unauthorized use.
– Mobility scooters for disabled individuals may have locked on-off switches to deter theft.
– Computerized keypads with secret codes are used to activate and deactivate switches.
– Combination code keypads are used in certain environments to restrict access to power tools.
Tamper-Resistant Switches
– Tamper-resistant switches are not intended for general use and require authorization.
– They may control functions like auditing, power tool operation, or security systems.
– Ignition switches in motor vehicles are a common example of tamper-resistant switches.
– Robust materials and additional security measures protect tamper-resistant switches.
– These switches often require keys, passcodes, or special access to operate.
Indicators
– Vandal-resistant switches can incorporate indicator lights or LEDs to show circuit activation, deactivation, or fault conditions.
– LEDs are commonly used in this type of switch, available in various colors and operating at low voltages.
– Single and ring-shaped groups of LEDs can display the current status of equipment or machines.
– Some products have LEDs with two colors to indicate multiple status conditions, such as On (green), Off (extinguished), or Fault (red).
– Mechanical means, like the position of a toggle handle or a brightly painted indicator flap, are also used to indicate switch status.
Non-Mechanical Types of Switches and General Electric Contact Materials
– Non-mechanical switches, such as piezo and capacitance switches, are longer-lived compared to mechanical contact-based switches.
– These switches have no moving parts, making them capable of lasting for tens of millions of operations.
– Glass reed switches use a thin metal reed that bends when a magnet is near, providing protection from moisture and dust.
– Piezo switches utilize the piezoelectric effect to generate an electrical signal when pressure is applied.
– Capacitance switches detect changes in capacitance to activate or deactivate the switch.
– General Electric offers a range of contact materials for switches.
– These contact materials are designed to provide reliable electrical connections.
– The materials are selected based on their conductivity, durability, and resistance to wear.
– General Electric’s contact materials ensure efficient electrical switching.
– The company’s contact materials catalog provides detailed information on available options.Sources: https://en.wikipedia.org/wiki/Vandal-resistant_switch
