Infra Red Sensor Monitor

The sensor/monitor shown in the diagram ‘wakes up’ the host system on detection of infra-red (IR) signals. It draws so little supply current that it can remain on continuously in a notebook computer or PDA device. Its ultra-low current drain (4µA maximum, 2.5µA typical) is primarily that of the comparator/reference device, IC1. The circuit is intended for the non-carrier systems common in infra-red Data Association (IrDA) applications. It also operates with carrier protocols such as those of TV remote controllers and Newton/Sharp ASK (an amplitude shift keying protocol developed by Sharp and used in the Apple Newton).

The range for 115,000-baud IrDA is limited to about 6 in (15 cm), but for 2400-baud IrDA, it improves to more than 12 in (30 cm). Immunity to ambient light is very good, although bright flashes usually cause false triggers. To handle such triggers, the system simply looks for IR activity after waking and then returns to sleep mode if none is present. The sensor shown, D1, a relatively large-area photo-diode packaged in an IR-filter material, produces about 60µA when exposed to heavy illumination, and 400mV when open-circuited. Most photo-diodes may be used. Operation is in the photovoltaic mode without applied bias.

This mode is slow and not generally used in photo-diode circuits, but speed is not essential here. The photovoltaic mode simplifies the circuit and saves a significant amount of power. In a more conventional configuration, for instance, photo-conductive, photo currents caused by ambient light and sourced by the bias network would increase the quiescent current about ten times.

2012 Citroen C3 Red Block New Supension

The Citroen come at the Geneva Motor Show to reveal the production variant of the C3 Red Block comes with more dynamic suspension settings – roughly 50% more stiffness and nearly 25% less roll – with the steering adapted to the new suspension settings for a more defined road feel. The body height has been lowered 25mm and ESP has been fitted as standard for even more verve and control. C3 Red Block is available with three engines, VTi 120 petrol, e-HDi 90 diesel and e-HDi 100 diesel, mated to manual gearboxes.

Outside, the Shark Blue body paint is combined with a bumper strip in the same colour. The other body colours – Banquise White, Aluminium Grey, Manitoba Grey and Obsidian Black – come with a gloss black bumper strip. The door mirrors and door handles are finished in Obsidian black. The 17-inch diamond-effect wheels are fitted with 205/40 tyres and chrome trim complete the exterior look.

Inside, C3 Red Block features a gloss black dashboard fascia, while the pedals and front door surrounds are finished in aluminium. The diameter of the steering wheel has been reduced by 20mm to further enhance driving pleasure with a tighter feel. Special red leather seat upholstery is available as an option.