The excellent Pulses and comments to those Pulses about LED lighting got me thinking about what "industry" is doing with LEDS and I'd like to describe one application here - indicating lights on push buttons and switches on machinery.My company (and many others) have already or are in the process of changing over our 24V DC control switches and push buttons to those which utilise LEDS as the indicators rather than 24V DC incandescent lamps as the indicators. The LED current is quoted as less than half that of the standard lamp (18mA compared to 40mA) and visually there is no loss of illumination when changing to the LED. The new units are designed for 24V AC or DC – they must have rectification in-built. We haven’t had an LED unit fail in 2 ½ years when the original lamps would fail frequently.I have attached a photo which shows the “new” pushbutton on the left (top with actuator, bottom without) and the “original” on the right (again, top with actuator, bottom without). Apologies for one being orange and the other green but they all come in a range of colours anyway….

Now to the point – to achieve this change, the switch manufacturers made the change-over very easy. The new units fit the same size penetration, come in the same (if not larger) range of functions and colours and have a similar terminal layout on the back. I’m sure someone soon will do the same for domestic light fittings and will come out with a cheap, easy change-over a qualified and licensed Electrician can do in minimal time (hence at minimal cost). This will enable us to use “LED lamps” from a light fitting which is still running from mains voltage and frequency and not have the “smarts” in the lamp, but have them in the fitting. This will enable us to use LEDs in place of "standard" light fittings as well as still having the opportunity to buy "special" fittings whne we want something "showy".