AVR-Chat

On Sunday, November 30, 2003, at 05:09  PM, Les Grant wrote:

> Hi Mark,
>
> I don't know these optos but, as a general rule, there are two things
> to watch out for. Current Trandfer Ratio (CTR) and speed. CTR is a
> bit like bipolar transistor beta - it is the ratio of output
> (collector) current to input (LED) current and is commonly as low as
> 20% (0.2). You mention a 330R input resistor but not the voltage of
> the receiver output. Do you have an oscilloscope to view the receiver
> output?

The CTR can also change pretty drastically over temperature too...

Mike