Date: Tue Mar 31 15:08:17 2009 Back to Contents ------------------------------------------------------------------------

Author: Santos Ramirez

Subject: VDG question



A professor here ordered a
Cenco Large Van De Graaff # CP33891-00
from Sargent-Welch last week (description follows).

Problem is - it does not generate very large sparks.

Has anyone else had problems with this VDG?
Is it fixable?

(We have 2 old (circa 1960) VDGs that work great and
the one ordered was the only one close in style to the old ones)

TAMU -Physics

Generates 400kV. 105k More than Any Other Van de Graaff!

Based on the well-known Van de Graaff system, our newly improved design
features a large 28cm diameter collector sphere, a substantial 12.5cm
diameter x 56cm high transparent insulating column, a completely enclosed
base with a variable-speed motor, and an integrated discharger on a
movable arm for controlling the length of the sparks and discharging the
sphere after use. The long column and the smooth finish substantially
reduce charge loss by leakage and spray discharges, which results in
improved reliability and greater maximum spark length. The generator can
develop voltages up to 400kV under favorable conditions. The low average
current of about 10žA or less prevents harmful shocks. Peak current
generated is about 50žA. Operates under all humidity conditions
encountered in the classroom. With 3-wire line cord and switch for 110V,

From Tue Mar 31 15:08:17 2009