USGS WWW Pages: National | Pasadena | Western Region
by Daryl Baisley
Electrical/Electronical Seismic Technician
Allied Signal - at USGS Pasadena Field Office
(last update 8/30/96)
This page describes a 24 Volt DC upgrade power supply system that is
being used to replace the existing AC (and 12 Volt DC) systems supplied
with various GPS units used in the SCIGN
continuous GPS network. The reason for the upgrade is to provide backup
battery power to the modem, as well as longer backup power operation of
the GPS receiver itself. The backup power is required in case of prolonged
power outage or brownout conditions. This system will also require fewer
maintenance visits in the long term.
We are upgrading all vendors' units that have been in use over the past several years (in particular the Ashtech Z-12 and the Osborne Turborogue - this system would also work well for upgrading the Trimble 4000 SSE power supply). More recently available units from these same vendors may not require this type of modification.
Figure 1. -
NEMA box and components; design and layout of the equipment
enclosure. See Fig. 2 for the wiring connections between
system components.
Figure 2. -
Power supply board; design and wiring diagram used to
connect GPS and modem equipment within the NEMA
enclosure shown in Fig. 1.
System Component Parts and Supplies Required
GPS SYSTEM - 24 VOLT. BATTERY BACKUP POWER SUPPLY UPGRADE
FOR CONTINUOUS MONITORING STATIONS
Qty. ....... Description
4 .......... Two Screw Terminal Strip 6 pole
1 .......... Xenotronix Power Supply Model # 8110 F/P
1 .......... Xenotronix Low Volt. cut-off model LVC-2
2 .......... Exide Mega Cycle Batteries group 30 with plastic battery boxes
1 .......... One Amp. "slo-blo" fuse with in-line fuse holder (3AG) for modem
1 .......... Ten Amp. Fuse ATC type with fuse holder ( oneside butt connector other 14-16 AWG 3/8" ring for stud on battery)
1 .......... Cinch Terminal Strip 4 post feed across 16-22AWG 4-140
3 .......... Strain relief ( Plastic for # 14 AWG)
4 .......... 16-14 AWG 3/8" ring for battery stud
4 .......... 16-14 AWG .187 Quick slide disconnects
Plenty ....... solder and Heat srink tubing sizes 1/8", 3/8", 1/2", 1/4"
........................ # 14 AWG Stranded Red THHN
........................ # 14 AWG Stranded Black THHN
........................ # 16 AWG Stranded Red
........................ # 16 Awg Stranded Black
........................ Tye wraps Small, Medium, and Medium with a Screw down
3 .......... # 10 Screws 1" wood
12 .......... # 4 3/4" Screws for wood
8 .......... # 8 1/2" Screws for wood
box ......... # 6 1/2" Screws wood
1 .......... piece of wood 8 by 10 1/2" for mounting inside NEMA box
box .......... # 6 and 10 Fork terminals for 14-16 AWG and 22-16 AWG
This report is preliminary and has not been reviewed for conformity with U. S. Geological Survey editorial standards. Any use of trade, product, or firm names is for descriptive use only and does not imply endorsement by the U. S. Government.
