Comparator circuit help

Thread Starter

Benjy

Joined Jan 24, 2011
2
Hi all,


I have been attempting to build a circuit on breadboard that responds to a change in light level. For this circuit, I am using a light to voltage converter (The TSL12S-LF) which successfully outputs up to 5 Volts into a comparator (The LM311N).

The problem is that no matter what the differences are between the voltages on both inputs to the comparator, there is nothing coming out.

I have drawn a relevant diagram to help explain what I am talking about.

I have nothing connected to "strobe" and "balance"


Any ideas why Vout is always zero? Have I completely misunderstood a concept? I'd love to know!


Much appreciated,
Ben
 

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hgmjr

Joined Jan 28, 2005
9,027
That is a classic mistake with the LM311. If you search this forum you will find quite a few threads from members having this same problem as you with the LM311.

hgmjr
 
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