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← FS-5000 ← Charger ← Batteries
WARNING —
Anyone with an FS-5000 in his or her collection, who wishes to use or
demonstrate the device, MUST read the following notice.
Inside the mains
power supply unit (PSU)
are a number of capacitors that are likely to explode after a number of years.
It is important to replace all RIFA capacitors in the PSU before connecting
the it to the mains. ➤ Learn more...
The image on the right shows the PSU which has no controls.
At the right is a socket for input from the mains. The wide-range PSU accepts
any AC voltage between 110 and 240V. To the left of the mains socket is
the main fuse (4A slow-blow). A spare fuse is stored below the plastic
cap on top of the unit.
At the bottom of the PSU are two large contact pins
that carry the 14V DC output voltage.
When the PSU is mounted on top of the battery charger,
these pins line-up with similar pins in the top lid of the charger.
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The PSU is a Switched Mode Power Supply (SMPS) with a wide-range input
(110-240V AC).
The advantage of the SMPS principle is that PSUs can be made much smaller,
as they don't need a bulky transformer, and are highly efficient (approx.
80% at the time this PSU was designed).
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Because of the high voltages, a protective
plastic cover is present between the PCB and the
top lid.
The image on the right shows the
interior of the PSU after the plastic cover
has been removed.
The PSU consists of a single PCB with an
SE5560 controller
at its heart
[1].
One of the disadvantages of an SMPS is that it generates rather strong
(unwanted) spurious signals that can cause interference with the reception
of weak radio signals. Such side-effects are generally classed as EMC-problems,
which are extremely difficult to solve.
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Although the designers of the FS-5000 made an enormous effort to avoid any
EMC problems with this kit, the spurious signals from the PSU are not
sufficiently suppressed. As the FS-5000 was specified for a range of no less
than 6000 km, it was advised to power the radio station always from the
batteries. In some countries a modification was carried out that made it
impossible to connect the PSU/Charger to the transmitter. The modification
consisted of a plastic panel that was mounted over
the input connector of the transmitter.
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It should be noted that inside the PSU – on the primary side – are a
number of capacitors that are connected directly to the AC mains.
These capacitors – made by RIFA – are likely to explode. Over time, they
will have developed cracks, as a result of which
moisure can enter the body and react with the aluminium foil inside.
RIFA capacitors are notorious for this [2], and one FS-5000 user in Germany
has already reported an explosion, which caused the main 16A house fuse
to blow [3].
If you want to use or demonstrate your FS-5000, it is mandatory to
replace all RIFA capacitors inside the PSU, before connecting it
to the AC mains again. To do this, take the following steps. In case of doubt,
make a photograph of the interior first, so that you know what goes where.
Do this only if you know exactly what
you are doing. If you are uncertain, ask someone else for help.
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- Note that some components carry the live 220V AC mains voltage, which may potentially be lethal. If the device has recently been used, some capacitors may still be charged.
- Use a proper desoldering tool, preferably a desoldering iron. If you have no experience with desoldering components from a double-sided PCB, you might want to ask someone with the appropriate skills to do the job for you.
- Be careful not to damage the PCB tracks when desoldering the 4700 pF Y-capacitors. Note that it is a double sided PCB and that the through-plated holes are easily damaged.
- The two 6800 pF at the bottom edge of the PCB must also be swapped. They are series connected and are responsible for the supply voltage to the control logic. Substituting them with a different value may damage the electronics.
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© Crypto Museum. Created: Friday 20 August 2010. Last changed: Wednesday, 14 October 2020 - 15:47 CET.
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![Several RIFA capacitors from and FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18875.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18868_thumb.jpg "image # rifa/karsten_18868.jpg")
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18870_thumb.jpg "image # rifa/karsten_18870.jpg")
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18871_thumb.jpg "image # rifa/karsten_18871.jpg")
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18872_thumb.jpg "image # rifa/karsten_18872.jpg")
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18873_thumb.jpg "image # rifa/karsten_18873.jpg")
![Several RIFA capacitor from an FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18875_thumb.jpg "image # rifa/karsten_18875.jpg")
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18874_thumb.jpg "image # rifa/karsten_18874.jpg")
![PCB with the RIFA capacitors removed. Photograph by Karsten Hansky [3].](img/rifa/pcb_no_rifa_thumb.jpg "image # rifa/pcb_no_rifa.jpg"){kind=small}
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18868.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18870.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18871.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18872.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18873.jpg)
![RIFA capacitor from FS-5000 PSU. Photograph by Karsten Hansky [3].](img/rifa/karsten_18874.jpg)
![PCB with the RIFA capacitors removed. Photograph by Karsten Hansky [3].](img/rifa/pcb_no_rifa.jpg)