Equipment List: 9 total setups
- E/M apparatus
- High Voltage Power Supply
- Low Voltage Power Supply
- Ruler
- Banana plug cables:
- Meter stick
General Class use :
- Bar magnest
Notes and tests:
- CAUTION: the voltage to the heater of the electron gun should NEVER exceed 6.3 volts. Higher voltages will burn out the filament and destroy the e/m tube.
-
Before applying power, set the current and voltage adjustment knobs as follows:
a. Helmholtz Coil current, counterclockwise
b. Low Voltage:
DC current, clockwise
DC voltage, counterclockwise
c. High Voltage, counterclockwise - In order to shade the e/m tube from room lights, place the hood over the e/m apparatus.
- Turn the current adjust knob for the Helmholtz coils to the OFF position.
- Connect your power supplies and meters to the front panel of the e/m apparatus.
- There are two power supplies which need to be set. One supply, the Pasco model SF‑9585 High Voltage Power Supply, provides power to the electron gun. The other supply, the Pasco Model SF‑9584 Low Voltage Power Supply, provides power to the Helmholtz coils.
- Adjust the power supplies to the following levels:
Electron Gun (high voltage power supply)
Heater. 6.3 VAC
Electrodes: 150 to 500 VDC (keep the VDC ~ 450 V as you vary the orbits using the Helmholtz coils)
Helmholtz Coils: 6‑9 VDC (low voltage power supply)
(set this using the instructions for “constant voltage mode” described for the low voltage power supply). Keep the current in the range of 1-2 A for best results.