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Open Collector?

Hi,

I just built Velleman 8061 and got it eventually working - I think?

But I have a question.

Shouldn't I be able to see whether line is active by resistance meter over the transistor?

If I have understood right the resistance over the transistor should change when line is on or off?

Now the resistance meter shows only infinity whether the line is 0 or 1.

I can't understand ...

Best Regards Kari

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PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com   (I am just a satisfied customer)
Reply to
Kari Laine
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Connect a resistor from a digital output to the positive supply, then measure the voltage between the digital output and ground.

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Peter Bennett, VE7CEI  
peterbb4 (at) interchange.ubc.ca  
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
Reply to
Peter Bennett 

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Try this: (View in Courier)


                C-------+
VIN>---[R]----B NPN     |+
                E   [OHMMETER]
                |       |-
GND>------------+-------+

or this:

                C-------+
VIN>---[R]----B PNP     |-
                E   [OHMMETER]
                |       |+
VCC>------------+-------+
          
JF
Reply to
John Fields

THANKS !

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com   (I am just a satisfied customer)
Reply to
Kari Laine

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