Electronics companies are always searching for new ideas for switches, and one of the latest developments is a mains switch that turns itself completely off.It addresses the need to save stand-by power, and was introduced by Japanese company Omron in two main versions.
The company has released a manual mains switch, called the Remote Reset model, and a so-called “delayed-off” switch.
The manual mains switch has a coil inside that flips to the “off” position after the application of 5V for 50ms.
Unlike with a latching relay, the coil cannot set it to the “on” position.These rocker switches were brought out to be part of systems that meet a directive of the European Commission.
The EU’s initiative is to improve energy efficiency by 20 per cent by the year 2020. It aims to reduce the environmental impact of energy-related products (ErPs), including the energy consumption throughout their entire life cycle.
Their ErP Ecodesign directive specifies a limit of 0.5W of power consumption of equipment in any off-mode condition. In stand-by, consumption should be limited to 0.5W, or 1W where the equipment has a status display.
Compliance with the directive not only saves cost for the end consumer, but also prolongs the life of electrical equipment by ensuring that it is properly powered down when it is not required.
The switches are called A8GS, and look like a normal mains rocker switch. They are rated for 16A at 125Vac and 10A at 250Vac.They use either silver alloy as contact where there is a minimum load of 5Vdc 200mA, or a gold alloy that works down to 2Vdc 1mA.
Omron has versions where the coil is supplied through a 2pin connector, as well as all-manual versions without a coil.
The “delayed-off” rocker switch does not actually have a delay built in, but features a delayed off function to allow safe shut down of electrical equipment.
The power to the system is maintained when the switch is returned to the off position, with the system then being powered down by an external signal determined by the designer.
The company say this prevents issues with data loss or circuit damage through forced power off by the user, and can help safer application design.
It is a triple pole single-throw switch where all three pairs close simultaneously when the switch is manually set to “on”. The power contacts can only be turned on by the rocker, and off by the coil.
The signals contact is closed when the switch is manually set to the “off” position. The electronics can then run an orderly shut-down procedure, then actuate the coil to cut mains power.
The switches save energy by cutting the standby power, and by preventing the user forgetting to turn off the main power.
It means main power can be turned off by remote, and the main power of many pieces of electrical equipment can be turned off at the same time.
The Omron A8GS is the smallest rocker switch with a reset function on the market, and is ideal for use as a power switch for a whole range of industrial and consumer electrical applications, featuring high inrush current durability conforming to TV-8 standards.
Innovative design has enabled Omron to reduce the size of the new switch to just 30mm x 17mm x 28.5mm, less than half the size of its existing non-resettable equivalent.