Testing for a Fried LM358 OpAmp IC AND, ID''ing an emitter/collector?
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I've been working my way throught the Parallax tutorials and am doing
experiment 2 from the Industrial Control Tutorial, constructing the
circuit on page 45...the Retro-reflective Switch.
A moment of carelessness caught me when I was re-constructing a #7805
regulator section...and a cap blew. The 7805 is fine. An IC, a National
Semiconductor LM358 was on the breadboard at the time.
I'm trying to measure a voltage change in an infared detector when a
sheet of paper is brought near the detector/emitter pair. I'm not
registering a change, just a constant 5VDC.
I figure either the circuit is incorrectly assembled or quite possibly
I fried the LM358.How would I test the LM358 for damage? I've got a
digital probe & DMM. I'm not certain what I should be testing for.
One last thing. I'm using an infared emitter/detector pair from
Radioshack (item #276-142). The component documentation (back of
cardboard display/pack) is somewhat less than clear. It has a graphic
image of a two lead Detector: cathode an anode. Also, mention is made
of a collector and Emitter (I don't know how that translates to cathode
and anode), as well another graphic image, this time a transister
schematic:
___
/ \
___v \____
(the "v" is an arrowhead)
Is the arrow the anode or cathode in this transister?
The only schematic references I have that look similiar, are NPN or
PNP transistors, and they're of no help.
If anyone can shed a little light here I be much appreciative.
Thanks.
Cheers,
-Neal
P.S. regarding the earlier in/out pins and chips question, I'm
digesting the info but want to complete this experiment before I move
forward.
experiment 2 from the Industrial Control Tutorial, constructing the
circuit on page 45...the Retro-reflective Switch.
A moment of carelessness caught me when I was re-constructing a #7805
regulator section...and a cap blew. The 7805 is fine. An IC, a National
Semiconductor LM358 was on the breadboard at the time.
I'm trying to measure a voltage change in an infared detector when a
sheet of paper is brought near the detector/emitter pair. I'm not
registering a change, just a constant 5VDC.
I figure either the circuit is incorrectly assembled or quite possibly
I fried the LM358.How would I test the LM358 for damage? I've got a
digital probe & DMM. I'm not certain what I should be testing for.
One last thing. I'm using an infared emitter/detector pair from
Radioshack (item #276-142). The component documentation (back of
cardboard display/pack) is somewhat less than clear. It has a graphic
image of a two lead Detector: cathode an anode. Also, mention is made
of a collector and Emitter (I don't know how that translates to cathode
and anode), as well another graphic image, this time a transister
schematic:
___
/ \
___v \____
(the "v" is an arrowhead)
Is the arrow the anode or cathode in this transister?
The only schematic references I have that look similiar, are NPN or
PNP transistors, and they're of no help.
If anyone can shed a little light here I be much appreciative.
Thanks.
Cheers,
-Neal
P.S. regarding the earlier in/out pins and chips question, I'm
digesting the info but want to complete this experiment before I move
forward.