Quick Answer: Teltron Tube - Planar Diode is a high-vacuum electron tube with a thermionic cathode for demonstrating the Edison effect, emission current against applied voltage, and the use of a diode as a rectifier.
Last updated: October 2026
Key Features
Glass spherical body with cylindrical neck, tungsten filament and circular anode plate
4 mm sockets in the plastic cap and a 4 mm plug connection on the sphere
Current flow between an incandescent filament and a cold electrode (Edison effect)
Anode current/anode voltage characteristic curves for different filament temperatures
Application of a diode as a rectifier
e/m by the displacement method using Helmholtz coils (optional)
Technical Specifications
Specification
Value
Maximum anode voltage
500 V
Anode current
2.5 mA at 300 V
Maximum filament voltage
7.5 V AC/DC or less
About This Product
The tube is used to investigate how the measured emission current relates to the voltage applied to the cathode, and to study diode characteristics through rectification. Operating instructions are supplied. Operation needs a bench power supply for the filament, a universal stand, 4 mm leads and an EHT power supply for the anode with 3 EHT experiment leads. The Teltron Tube - Planar Diode is available for supply within India and for export to Belize, Equatorial Guinea, Eswatini, Bangladesh, Latvia and Guyana.
Frequently Asked Questions
Q1. Are Helmholtz coils needed? They are optional. With Helmholtz coils, e/m can be determined by the displacement method.
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