The Museum of HP Calculators

HP Forum Archive 14

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How bright is your HP33E
Message #1 Posted by Ronald on 31 Oct 2004, 5:00 p.m.

Hello,

I bet this one is brighter than yours. Have a look: http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=38876&item=3849820953&rd=1#ebayphotohosting

Do not forget you sunglasses.

Ronald

      
Re: How bright is your HP33E
Message #2 Posted by marais on 31 Oct 2004, 5:09 p.m.,
in response to message #1 by Ronald

How come the 33E is still alive? I thought they were rather picky about their input voltage?

A.

            
Re: How bright is your HP33E
Message #3 Posted by Ronald on 31 Oct 2004, 5:47 p.m.,
in response to message #2 by marais

It takes only 5 seconds to take a picture .............

                  
Re: How bright is your HP33E
Message #4 Posted by Chan Tran on 1 Nov 2004, 11:38 a.m.,
in response to message #3 by Ronald

I don't know about that 33E on ebay but I had the 9825B for a few years. As you all know the 9825B has 32 character 5x7 LED dot matrix display. The display is so bright that after a night working with it the next morning I saw everything cyan...

                        
Re: How bright is your HP33E
Message #5 Posted by Ronald on 1 Nov 2004, 3:18 p.m.,
in response to message #4 by Chan Tran

So that was by design. This Seller put a 9 volt battery where it was designed only for 2.4 volts. I am not so sure if this calculator will last a night.

                              
Re: How bright is your HP33E
Message #6 Posted by Vieira, Luiz C. (Brazil) on 2 Nov 2004, 12:19 a.m.,
in response to message #5 by Ronald

Hi;

I could not believe that! How come this poor HP33E is still alive after having 4 times its original voltage? After reading that a 9-volt battery was installed in the batteries compartment, I could figure out why was it so bright... In fact, if the LED display were eyes, their eyeballs would be popped out already... and if the IC's were brain cells, they'd be fried, too.

Poor little babe... What a loss! I guess it will never be able to work with 2.4 volts again.

What a loss...

Luiz (Brazil)

                                    
Re: How bright is your HP33E
Message #7 Posted by John Limpert on 2 Nov 2004, 4:56 a.m.,
in response to message #6 by Vieira, Luiz C. (Brazil)

Some logic families, like the old 4000 series CMOS chips, had a very wide range on the input voltage. I would be more concerned about the display overheating and failing due to excessive current.

            
Re: How bright is your HP33E
Message #8 Posted by Larry Corrado on 2 Nov 2004, 6:00 p.m.,
in response to message #2 by marais

Perhaps the battery is used, and internal resistance is decreasing the output voltage to somewhat less than its nominal value.

Larry

                  
Re: How bright is your HP33E
Message #9 Posted by Ronald on 3 Nov 2004, 8:34 a.m.,
in response to message #8 by Larry Corrado

I hope so (old battery), the buyer is othewise in for a tricky calculator.


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