Simple Electric System

The simple electric system on this page mimics ones typical in modern single engine airplanes- with a few twists, explained below.

Instructions / Normal operating checklist:

  1. Battery ... On
  2. Mags .... On
  3. Starter ... hold down start switch for several seconds until engine is running
  4. Alternator switch ... On
  5. Radio Master switch ... On
  6. Other electrics ... as desired

Notes about the above simulation:

The design of the above airplane is purposely defective - it does not have a large enough alternator to run all the installed equipment. If you turn everything on and retract the gear (click on the airplane) the alternator capacity is exceeded and the bus voltage drops. If the bus voltage drops below the battery voltage the battery will begin to feed the bus and the ammeter will show a discharge.

If you cause an over voltage the voltage which actually not be high because the over voltage relay (part of the voltage regulator) will activate and shut the alternator down.

Pay attention to how the alternator field keeps changing as you turn things on and off.

The simulation starts with the battery half discharged. You can charge it using the external power plug. The external power goes through three cycles:

  1. Connected properly
  2. Connected backwards (positive and negative reversed)
  3. Disconnected.

Note that you cannot connect external power if the alternator is operating.

Do you understand the reason for the relay in the external power circuit?

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