Ramsey Electronics PG13 Instruction Manual page 26

USING YOUR OWN POWER SUPPLY
AC Sources:
You will need to use an AC transformer capable of 3 AMPS in the range of
5VAC to 16VAC. 14VAC will give you the best performance and balance
between temperature and voltage output. You do not need to use a center tap.
Connect either side of your AC transformer to the lugs marked AC1 and AC2
on J1. Then connect a wire between the ground lug and a good earth ground,
like the ground pin of your AC line cord that you use to power the transformer
(usually green). If you only have a two pin connector, wire the ground wire to
the center screw of a wall plate. These are usually well grounded.
DC Sources:
Your power supply will be a critical factor in getting the best performance out
of the PG13. Do not use an adjustable supply as some have FET outputs and
may be destroyed by the high voltage. Your supply should be fixed output and
must meet these minimum specifications:
•
Voltage range: 5 volts (or less) to 15 volts (maximum)
•
Current capability: At least 3 amps continuous, 5 amps preferable.
•
Regulation: Non-critical; does not need to be regulated.
You may not want to deal with the 1.4 volts of drop across the bridge
rectifier, as this will cause you to lose some potential output voltage. This will
require you to remove your rectifier diodes, which will prevent you from using
an AC transformer until you replace the diodes.
Steps for converting your AC operated PG13 to DC operation.
1. Remove D2.
2. Remove D5.
3. Install a jumper made from spare component lead or a spare piece of
solid bus wire into the place where D2 was. The old clipped-off lead of the
diodes would be perfect.
4. Install a jumper into the place where D5 was.
You can leave the other two diodes in place since they will never be turned
on if you connect the power correctly. Now you will see that the terminal
marked AC2 also has a plus (+) symbol; this is where you will wire in the
positive, and AC1 will be where you wire in the negative.
Run a ground wire from the terminal marked GND to a good earth ground.
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PG13 26