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← FS-5000
← Batteries
FS-5000 Charger
Battery charger and power inverter

By default, the FS-5000 radio station is powered by rechargeable batteries. The batteries should be charged after use by means of a special battery charger that is part of the complete kit. Although it is possible to use the charger stand-alone, it is normally used in combination with the mains supply (PSU) that is stacked on top of it. The batteries can be charged in situ.

The image on the right shows the bare battery charger. The unit measures approx. 145 x 185 x 35 mm and has a small control panel at the top-front. One the control panel are buttons for starting a charge operation and for checking the status of a battery. A series of LED indicators show the current status. A 12V input allows an external (car) battery to be used as source.

On top of the unit are two contact pins. These are used to receive 14V power from the mains power supply unit (PSU) that should be mounted on top of it. This is the normal situation.
Battery charger and power inverter

On the left side of the charger is a large connector with 4 large contact pins and 17 smaller ones. When the charger is used as part of a complete FS-5000 radio station, this plug is connected to the mating socket of the transmitter. In that case the charger is mounted in the rear right corner, below the PSU. The control panel remains accessible even when the DSU is installed.

The batteries can be charged whilst they are installed in the radio station as long as the charger is connected to the transmitter. It is not possible however, to operate the station while charging is in progress.

It is also possible to charge the batteries off-line. In that case, the H-bar is used to connect the batteries directly to the charger. This mode of operation in shown in the image on the right. In some countries (e.g. Germany) this method was mandatory, and the PSU/Charger was never connected directly to the transmitter.
Charging batteries

The main reason for not using the PSU/Charger directly with the radio station, is the emission of spurious (radio) signals by the PSU. The PSU is a Switched Mode Power Supply (SMPS) which can cause interference with the reception of weak signals. This is generally called an EMC-problem.

The charger also contains a Power Inverter that allows any external 12V DC source, such as a car battery, to be used instead of the PSU. The inverter transforms and regulates the external 12V source into a stable 14V DC voltage for the FS-5000. This may also cause EMC-problems.

Battery charger and power inverter Stacked combination of PSU and Charger Stacked combination of PSU and Charger Complete FS-5000 radio station Close-up of the DSU when attached to the radio station Charging batteries Two FS-5000 batteries

The charger can be opened from the top by removing the bottom panel, that is held in place by 6 small bolts. It is roughly divided in two sections that are separated by a metal wall that is part of the case. Inside the unit are three PCBs of which the two at the left are stacked together.

The image on the right shows the interior of the charger after the top lid has been removed. At the right is the power inverter that takes the 12V from an external source and converts it into a stable voltage required by the FS-5000. The circuit is built around an SG1524 Regulating Pulse Width Modulator by Microsemi Corp [1].

The board on the left is the charge-management logic. It controls the charge progress and checks weather the battery is fully loaded. This board is connected to the smaller contacts of the output connector (at the bottom of the image).
Charger interior

Below the logic board is another PCB with the power source selection and supervision. It selects between an external 12V DC source (regulated to 14V by the power inverter) and the 14V input from the PSU. The output voltage produced by the charger is supervised by an SG1543 [2].

Charger interior Charger interior Power inverter Charge management logic Solder side of output connector Revealing the power selection and supervision Power selection and supervision Power selection and supervision

  1. Microsemi Corporation (LinFinity), SG1524 Regulating Pulse Width Modulator
    Datasheet. 4/90 Rev 1.1 2/94. 1994. Retrieved April 2012.

  2. Microsemi Corporation (LinFinity), SG1543 Power Supply Output Supervisory Circuit
    Datasheet. 11/91 Rev 1.1 2/94. 1994. Retrieved Aptil 2012.
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