LASER TRIM AIR CONVECTION SYSTEM
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2002-Feb-27
Laser trim technology used to tune the frequency perature (middle of range specified @ 35"C), the response of RF circuits requires tight temperature fans will be at full speed (maximum cfm), while a control during the tuning process. The laser trim minimum user defined temperature (middle of range air convection cooling system was designed to con- specified as 25°C) will result in zero fan speed (zero trol the temperature in laser trim enclosures with- chn). Lasering and equipment inside the enclosure out the addition of excess humidity while ensuring cause the increase in enclosure temperature. Ambi- integrity ofEM shielding. ent factory air temperatures may prove to be insufficiently cooler than the enclosure temperature Enclosure cooling is accomplished via the closed to provide required cooling capability. Chilled water loop system shown, in which the ambient factory radiators wrapped around the air flow ducts will be air is piped into the enclosure (via waveguides that utilized if this situation occurs as shown. To elimi- attenuate EMI at RF to 90 dB) at variable cfm nate the risk of the air convection system adding dependent upon the temperature measured at the humidity to the laser trim enclosure, the water tem- enclosure output. At a maximum user defined tem- perature will be kept above the dew point.