Hi

If you can take a picture of the charger label, enlarged and readable, perhaps we can confirm its suitability.

Usually charger(s) are set for a wide range of input voltages, EG: 100 - 240 volts.

Hopefully this is your product...

https://dl.dell.com/content/manual58348342-precision-7670-setup-and-specifications.pdf?language=en-us

Page 23

Table 20. Power adapter specifications 
Description Option one Option two
Type 180 W AC adapter, 7.4 mm - SFF 240 W AC adapter, 7.4 mm - SFF
Connector dimensions:
External diameter 7.40 mm 7.40 mm
Internal diameter 5.10 mm 5.10 mm
Power-adapter dimensions:
Height 22 mm (0.8 in.) 22 mm (0.8 in.)
Width 66 mm (2.6 in.) 66 mm (2.6 in.)
Depth 130 mm (5.1 in.) 143 mm (5.6 in.)
Input voltage 100 VAC x 240 VAC 100 VAC x 240 VAC
Input frequency 50 Hz–60 Hz 50 Hz–60 Hz
Input current (maximum) 2.34 A 3.50 A
Output current (continuous) 9.23 A 12.30 A
Rated output voltage 19.50 VDC 19.50 VDC
Temperature range:
Operating 0°C-40°C (32 °F–104°F) 0°C-40°C (32 °F–104°F)
Storage -40°C-70°C (-40°F-158°F) -40°C-70°C (-40°F-158°F)