UK power supplies help astronomers observe remote galaxies

The ALMA operations site is based in the Andes, which is 5100metres above sea level. Here, the Atacama Desert is considered as one of the driest places on Earth and remote control of the antenna array from a site based at lower altitude some 20km away was necessary. Hank Newton, integration electronics engineer in the Back-end Electronics Group (BEND) of ALMA project, said: "Surviving strong winds and temperatures fluctuating between -20 and 20^°C is quite a challenge even for the two electronic equipment racks inside each antenna. In these racks, we process the signal from the output of the cryogenically cooled antenna front-end and produce a digital output on fibre optic cable." To power the racks, the BEND team selected the Vega configurable power supplies as specific outputs requirements could be met, while the devices' 'smart' communication capability helped facilitate remote control. "We use the RS232 port on the Vegas to determine the health of the system, as well as to control the voltage and current settings," added Newton. "This remote control capability is another important aspect for the team's choice in power supply, as each antenna in the array operates fully automatically." Having three antennas observing in unison, provides the missing link to correct errors that arise when only two antennas are used and, according to the BEND team, paves the way for precise images of the Universe at unprecedented resolution. ALMA will eventually have at 66 antennas, using 132 Vega power supplies from TDK-Lambda - which can be placed on any of about 200 pads, spread over distances of up to 18.5km and operating as a single, giant telescope. When fully-functional, astronomers will study cold clouds of gas and dust, where new stars are being born and remote galaxies towards the edge of the observable Universe.