Audible tones continuity tester...

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Looks like it was expensive when it was new.
Yep, just an example of how it could be done.
 
4pyros said:
Looks like it was expensive when it was new.

Yep, just an example of how it could be done.
Click to expand...

No, I don't believe that circuit can be made to do what has been asked. Play with the component values that would be needed, and you will find out for yourself.

John
 
jpanhalt said:
No, I don't believe that circuit can be made to do what has been asked. Play with the component values that would be needed, and you will find out for yourself.

John
Click to expand...
Yes I under stand, but its not up to me, its up to the OP.
 
the one i have is a mili ohm meter designed to trace shorts apparently, i used one at school and they are really good, the one with the all in one probe like in your picture is really ace
 
From the service manual it seems that big probe works by detecting the magnetic field resulting from injecting current into the circuit under test. So it's a current-trace probe. The two smaller probes are for the Ohms test.
 
alec_t said:
From the service manual it seems that big probe works by detecting the magnetic field resulting from injecting current into the circuit under test. So it's a current-trace probe. The two smaller probes are for the Ohms test.
Click to expand...
is that for the 580? i have the 550 and i thought that was just ohms? and for detecting shorts? i must get it out again and have a look tomorrow
 
Seems like most of there modles have inject and trace for testing and repairing circuit boards.
 
mine isnt made anymore and i think it was the base model, they wernt chap and even now they can still cost a fair bit second hand unless you get lucky like i did
 
is that for the 580?
Click to expand...
Yes. The manual gives schematics for both models, but the Current-trace Module is only in the 580.

The Ohms unit works by passing a known current (switch-selectable according to Ohms range) through the resistance-under-test, DC-amplifying the resultant voltage across the resistance, then displaying the amp output and using it to vary the (audio) frequency of a square-wave generator. The square wave is used (indirectly) to drive a speaker. The audio frequency increases as the resistance decreases (contrary to what the OP wants).
 
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thanks i didnt think mine had the trace, its got the probe but thats because it was owned by a numpty
 
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