CHERRY’s D4 miniature snap action switch has been an industry standard for many years. Originally this style of switch became popular with appliance manufacturers, due to its small size and excellent current carrying capabilities. In the early day of domestic appliance design, the loads being switched were generally either motors or heating elements, hence the need to have a control solution that would handle perhaps a resistive load of up to 16 amps or a motor load of around 8 amps. Moreover, this needed to be powered from mains supply, therefore 250 volts a.c. was a must. The D4 series adequately met these challenges.
Nowadays however, the nature of the controls in an appliance has undergone radical change, for although the end power components may still be motors or heating elements, the heart of the majority of today’s appliances is the microcontroller. This is essentially a dedicated micro-computer. The requirements of these devices (computer inputs) are quite different from those traditionally demanded. They are very low power devices and because of this need for reliable switching at low currents and voltages, manufacturers have often shifted away to smaller input devices. CHERRY’s product offering does include suitable smaller products, for example the DB and its sealed cousin the DC snap action microswitch series.
Nevertheless, the mechanical nature of the moving parts of today’s appliances will in many cases still require a physically larger switching element. The CHERRY D41 switch range offers the mechanical requirements (force, movement, over-travel etc.) which these applications demand, but also can switch reliably currents of only a few milliamps at voltages of less than 5 v.d.c. The reason this can be achieved is the use of gold cross point switch design, which guarantees high mechanical life (in excess of 1 million operations) with low cost components. For although a gold alloy is employed as the switching medium, the amount of precious metal required is very small in comparison to traditional gold plated riveted contact designs. This offers affordability without compromising performance.
Because the basic envelope, mounting points, lever options and connection arrangements are as for the standard D4 snap action switch series, the D41 complements the existing range and no special components are required for adoption.