The battery voltage monitor was originally developed for a US West Communications project which used SRT sensors. The important criteria for the battery monitor was that they must be powered by the 415 volt batteries, because no AC voltage is allowed in the battery compartment due to spark and explosion possibilities.
This monitor is therefore a fully isolated device using transformers. These transformers operate with 5 mA of current, and changes a pulse width in a modulation technique according to the applied voltage. The output can either be 5 Vdc (full scale) or a 4 to 20 mA loop current, in which case the 4 mA is equivalent to the lowest DC voltage reading, and 20 mA is equivalent to full scale. The voltage range can of course be changed by modifying the design.
This unit will monitor from 30 Vdc to 600 Vdc. The package measures 3 x 2 x 0.8 inches with two 5000 volt test lead wires at one end, and an output twisted shielded pair cable coming from the other end.
Engineers at SRT are available to discuss any questions you might have on any of
our products. Often we are asked to customize or prepare special calibrations on
our sensors to suit customer needs. Please contact us at (800) 447-6805 and ask
for Dayle Smith or Doug McNutt, or FAX us at (719) 634-2601, or send E-mail