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Forté 12V UPS medium duty-cycle

Technical Summary Document

Overview Other features Operational Limitations Specifications


This power supply has been developed as a low-cost variant of our popular Centurion Heavy Duty UPS. The Forté is intended for operators who do not need a continuous transmit capability, but do require their office radio to talk to the mobiles during power cuts. The Forté provides the same UPS backup power of one or two 6Ah 12V sealed lead-acid batteries. The difference is that the Forté has a smaller battery-charge PSU of 40W. This combination is adequate to power a typical PMR fixed-mobile radio (5A). The battery is continuously recharging while the radio is not transmitting. With an average transmit duty-cycle of 50% the battery will be maintained at full charge.

Battery charge current is approximately 2.8A. It is expected that the radio will be left on in receive mode for 24-hours per day. This will consume up to 300mA. The difference, i.e. 2.5A, is available to make good the average transmit current taken from the battery. It is assumed that transmitting takes 5A, and that transmit duty-cycle will be 50% of the conversation time. Under these conditions, battery charge equilibrium is maintained: one minute of transmit time is restored by one minute of not transmitting.

With a fully-charged single battery, backup time will be over 2-hours of conversation time at 50% transmit, or 24-hours in continuous receive. A flat battery will take approximately three hours to fully recharge. The backup capability is doubled with the two-battery option.

The Forté is recommended for PMR users who may need up to sixteen hours of typical radio conversation time per twenty-four hour day. Operators who require heavier use such as talkthrough base stations should consider that a Centurion is justifiable for their application.

For price & delivery quotation speak to Monty Yousaf.

Technical queries to Stewart Harding or Paul Peppiatt.

Diplomat Communications Ltd. Telephone 01256 381656.

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Mains supply is from a separate mains adaptor. Standard unit is supplied with plug to UK 3pin specification. Other national standards and voltages are also available. Note that this makes no difference to the base equipment; the same model is used without modification for all countries.

An alarm indicates mains failure or output fuse blown. A discreet beep at long intervals means that the mains has failed, and that the Forté is now operating on internal battery power only. It is desirable to keep transmit time to a minimum until the power is restored. A continuous tone indicates the output fuse has failed. This should be rectified immediately. LED indicators on the rear panel show I/P and O/P power availability.

Output is electrically fully floating. Radio connects to pluggable terminal block. This is polarised to prevent accidentally reconnecting the radio in reverse. Terminal block has doubled positive and negative contacts for connection of further 12V equipment.

Battery is protected against deep-discharge. If the unit is left without mains power for too long, the deep-discharge protection will automatically switch off all further drain on the battery. This feature latches, and is reset by mains power being re-applied. When power is eventually re-applied, the battery should recover to full capacity. Another protection feature is the provision of a link to disable all drain on a charged battery during storage or transport. It is arranged as part of the output terminal block, such that simply removing the connector will disable the battery and all alarms and indicators. (Battery will still charge if mains power connected.) This feature is useful if an end-user is expected to store or transport the equipment without detailed technical instruction.


If the battery is flattened by use during a power-cut etc, it is desirable to allow the unit to fully recharge, to provide full protection for another power-cut. If the radio is heavily used, this may delay the time to fully recharge. The unit should not be left with a flat battery for long periods, as this will shorten the battery lifetime.

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230V -6% +10% AC only.
110 / 120V manufacturing option.
Other power sources subject to special quotation.

12V DC nominal. 13.6V operating.
Continuous or average output current 2.8A max.
Recommended maximum current 8A for 10 minutes. Fused 10A.

Operating range: -10°C to +40°C (+14°F to +104°F) at 0% to 95% RH non-condensing.
Base equipment case temperature rise in free air, at continuous maximum rating: 5C max.
Mains adaptor case temperature rise in free air, at continuous maximum rating: 40C max.


Length:      280 mm  (11.0in)                                                  
Width:       190 mm   (7.5in)                                                  
Height:      125 mm   (4.9in)                                                  

Weight       3.8kg    (8.4lb including single battery & mains adaptor)         

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