5M10.53 - Burn or Blow a Diode

Code Number:
Demo Title:
Burn or Blow a Diode
Over voltage, Incorrect Direction
Area of Study:
Electricity & Magnetism
Diodes, Small Holder Boards, Variac with On/Off Switch, Large Isolation Transformer, Voltmeter (if desired), Safety Glasses.

Safety Glasses are required for this demonstration!

Plug the Variac into the isolation transformer.  Connect the diode directly to a Variac with an on/off switch.  With the switch on the Variac in the off position, turn Variac to its maximum voltage setting.  When the switch is turned on, the diode will either burn or blow dramatically.

The 1N459 diodes will blow or vaporize with a loud bang.

The 1N4001 and 1N4002 diodes are 100 volt diodes so they will slowly heat up, then glow, and then finally burn up.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.