EMRFD Message Archive 2586

Message Date From Subject
2586 2009-01-10 00:00:06 Dave - WB6DHW Re: Opto Circuit
peepholenz wrote:
> Quick look - minor points:
> 1. Base of left-hand 4401 has no connection 'blob' to collector of 3906.
> Actually, it is connected right at the collector. But, I re-drew to make it clearer.
> 2. Is 10K correct for resistor between 914 diode and uP_Vdd ?
> I think it is very non-critical. But, I changed it to 2.2K to be the same as the circuit driving the Si570.
> 3. U19 pin 5 should be earthed.
> Yes. I missed that one on the drawing. Somehow it got deleted when I made the drawing changes.
> 4. T2 phasing dots need fixing.
> That is the way Mini-Circuits shows it. It is a transmission line transformer rather than a regular transformer.
> 73
> Peter
Very good eyes, Peter. I will upload the corrected schematic in a
couple of minutes now.

Dave - WB6DHW