










Power transformer
VA wattage and Heatsink C/W calculator for AC/DC and PowerStation power supply kits



Highest AC IN to 0v voltage


Vac


Voltage +V1 is set to


Vdc


Voltage V1 is set to


Vdc

Unreg volts to +/V1 & V2


Vdc


Current draw of +V1


Amps


Current draw of V1


Amps

Doubler (2) Tripler (3)


times


Wattage used by +V1


W


Wattage used by V1


W

Unreg voltage to 48v reg


Vdc


Wattage wasted in reg by +V1


W


Wattage wasted in reg by V1


W

Voltage +48v is set to


Vdc


Total +V1 Wattage


W


Total V1 Wattage


W

Current draw of +48v


Amps


Heatsink C/W Rating for +V1


C/W


Heatsink C/W Rating for V1


C/W

Wattage used by +48v


W


Wattage wasted in reg by +48v


W


Voltage +V2 is set to


Vdc


Voltage V2 is set to


Vdc

Total +48v Wattage


W


Current draw of +V2


Amps


Current draw of V2


Amps

Heatsink C/W Rating
for +48v 

C/W


Wattage used by +V2


W


Wattage used by V2


W


Wattage wasted in reg by +V2


W


Wattage wasted in reg by V2


W

Total Transformer Wattage


VA


Total +V2 Wattage


W


Total V2 Wattage


W

Total Heatsink C/W Rating


C/W


Heatsink C/W Rating for +V2


C/W


Heatsink C/W Rating for V2


C/W

Note 1. Power transformer secondary voltages are likely to be
10 to 20% higher than the stated value with no load on the power supply so is
best to add this amount.
Note 2. Unreg volts to +/V1 & +/V2 & +48v needs to be at least 6v higher than
the reg dc voltage you need.
Note 3. All 1000uF cap voltage rating needs to be equal to or higher than Unreg
volts to +/V1 & +/V2.
Note 4. Heatsinks needs to have a C/W rating lower then on the above
table. The lower the C/W rating the better. If C/W rating is higher than 50 then no heatsink is required.
Note 5. When doing AC/DC calculations make sure +V2 and V2 have 0 current
values.
Note 6. If you have disabled the Doubler/Tripler to use the 48v as another +V
rail just enter 1 into the Doubler/Tripler box. 