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AC GOOD/POWER GOOD

TBC/LTBC SERIES
“AC Good” and “Power Good” alarm outputs provided consist of a TTL type output. Pin 13 (AC Good) will go HI when AC line is above approximately 90 VAC or 180 VAC. Likewise, Pin 15 (Power Good) will go HI when DC output is approximately 90% or higher of rated DC output voltage. Either alarm output will source or sink up to 25 mA referenced to Main DC output Pin A7. “Inhibit” Pins 11 & 12 shorted to output GND “Pin A7” will shut down supply; left open, supply will operate normally.

Additional options available. Contact the factory for additional information.

INHIBIT OPTION

The inhibit option turns the power supply off, using a secondary referenced switch or signal. As shipped from the factory, the power supply will operate normally with no connection required to the inhibit pins (11, 12). Normal voltage on pins (11, 12) will be approximately 4.5 to 5.5 VDC. A current of 2 mA from Pin 11, 12 to output ground (RET) will turn off the supply. If the inhibit pin (11, 12) is directly shorted to ground via a signal transistor or mechanical switch, the maximum current will be 5 mA.

LOW VOLTAGE BATTERY DISCONNECT (LVBD)

THE LOW VOLTAGE BATTERY DISCONNECT (LVBD) OPTION ADDS A NEW DIMENSION TO BATTERY BACK-UP OF THE TECHNOLOGY DYNAMICS LINE OF HIGH RELIABILITY POWER SUPPLIES. THE DC OUTPUT OF THE POWER SUPPLY SIMULTANEOUSLY CHARGES THE BATTERY AND POWERS THE LOAD. WHEN AN AC INPUT POWER FAILURE OCCURS, THE BATTERY CONTINUES TO POWER THE LOAD WITHOUT ANY POWER INTERRUPTION TO THE LOAD.

THE LVBD MODULE OPTION ELECTRONICALLY MONITORS THE BATTERY VOLTAGE. WHEN THE BATTERY VOLTAGE GOES BELOW A PREDETERMINED (ADJUSTABLE) LEVEL, THE LVBD MODULE AUTOMATICALLY DISCONNECTS THE BATTERY, THEREBY PROTECTING THE BATTERY FROM A COMPLETE DISCHARGE. THIS LEVEL IS USUALLY SET TO CORRESPOND TO ABOUT 1.67 TO 1.7 VOLTS PER CELL OF THE BATTERY.

THERE ARE THREE VERY SIGNIFICANT BENEFITS TO THE USE OF THE LVBD MODULE TO PROVIDE BATTERY BACK-UP. THESE ARE:

  • NO POWER INTERRUPTION WHEN BATTERY OPERATION IS REQUIRED.
  • 100% EFFICIENCY WHEN BATTERY OPERATION IS USED.

BATTERIES ARE PROTECTED FROM PERMANENT DAMAGE BY EXCESSIVE DISCHARGE
SINCE THE BATTERY IS CONNECTED ON THE OUTPUT OF THE REGULATED POWER SUPPLY, IT IS NOT POSSIBLE TO OVERCHARGE THE BATTERY. THE USUAL RECHARGE VOLTAGE FOR A SEALED LEAD ACID BATTERY WHEN OPERATED IN A “FLOAT” APPLICATION IS 2.3 VOLTS PER CELL. FOR A TYPICAL 24 VDC APPLICATION, THERE WOULD BE 12 CELLS, THUS 12 TIMES 2.3 VOLTS PER CELL, OR 27.6 VC. THIS CORRESPONDS TO THE POPULAR 28 VC OUTPUT.

AFTER A UTILITY POWER FAILURE OCCURS, IT IS NECESSARY TO RECHARGE THE BATTERIES. SINCE THE BATTERIES ARE CONNECTED ON THE OUTPUT BUS, THE RECHARGE OCCURS AUTOMATICALLY. THE BATTERY WILL ONLY BEGIN TO ACCEPT CHARGE WHEN THE DC VOLTAGE GOES ABOVE THE NORMAL OPEN CIRCUIT VOLTAGE OF THE BATTERY. AS THE BATTERY VOLTAGE GOES HIGHER (TOWARDS THE 2.3VOLT/CELL LEVEL), THE BATTERY CURRENT WANTS TO INCREASE.

IN THE EVENT OF A SHORTED CELL OR A SEVERELY DISCHARGED BATTERY, THE POWER SUPPLY WILL GO INTO A “CURRENT LIMIT” MODE AND THEREFORE STARVE THE BATTERY, BUT NOT THE CRITICAL LOAD.

OUTPUT NOISE MEASUREMENT
NOTE: CONTACT PROBE TIP AND GROUND RING AS SHOWN.

USING PROBE GROUND CLIP WILL CAUSE FALSE READINGS.

MEASUREMENTS ARE TAKEN WITH THE OUTPUT BEING MEASURED

APPROPRIATELY LOADED.