Warning: session_start() [function.session-start]: open(/home/content/10/6202210/tmp/sess_alpect86dno8h3a7v4uk7r2i72, O_RDWR) failed: No such file or directory (2) in /home/content/10/6202210/html/includes/functions.php on line 2

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/content/10/6202210/html/includes/functions.php:2) in /home/content/10/6202210/html/includes/functions.php on line 2

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/content/10/6202210/html/includes/functions.php:2) in /home/content/10/6202210/html/includes/functions.php on line 2
High Voltage Power Supplies
 
  Home Buying Guide Articles News br Reference Books Contact Us
High Voltage Info    
 
Home
Buying Guide
Articles
HV News
Reference
Books
Applications
Contact Us
Add Your Company to Buying Guide
NEWSLETTER
» Ask a Technical Question
» Free Product Selection Service
» Register for Free High Voltage Newsletter
» Read High Voltage Stories
» Add Your Company to Buying Guide
"We are your high voltage reference.  Please contact us with all your high voltage questions."
-- Fred Wright
 
 
High Voltage Stories »
(Email us your stories!)


"High Voltage" or is it "Low Voltage"?

Let me see if I’ve got this straight. The “High Voltage” light on a Cesna 172 N (and similar models) is actually a low voltage light. Cessna calls it a high voltage light because the most probable cause of low voltage is high voltage causing the alternator to go off line. In that case, the light labeled “High Voltage” would be telling you that you now have low voltage because you used to have high voltage. Perhaps it should have been labeled the “Formerly High Voltage” light.

If your high voltage protection is disabled due to equipment malfunction or someone putting a wire on the wrong terminal, and you get a high voltage condition, the high voltage light will not come on. It will remain dark until frying radios, smoke, or some other subtle indication alerts you to the fact that something is wrong. In fact, the light will never come on under a high voltage condition, only a low voltage one. It will come on if there is low voltage for any reason but, it’s a “High Voltage” light so you might not know that you actually have low voltage.

They could have called it a “Low Voltage” light. That would explain why it always comes on when there is low voltage such as when the alternator is off. The pilot would then have to figure out that the most probable cause of low voltage was not having an alternator any more. Cessna must have figured that was too much brain work for someone who meets the minimal standards for a PPL.

I always wondered where Microsoft got the engineers who designed a computer that you turn off by clicking “Start”. Now I know. They hired them from Cessna!

-Bob C.

Back to HV story listing

 

 

Warning: Unknown: open(/home/content/10/6202210/tmp/sess_alpect86dno8h3a7v4uk7r2i72, O_RDWR) failed: No such file or directory (2) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct () in Unknown on line 0