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1

The problem is that the optocouipler current must flow from the vreg of the controller. 5V into 2.3K is about 2mA. that current is comiing from the 4-20mA loop - so there's your minimum 2mA to fix: Swap the opto-coupler output and R2 This will invert the sense of the optocoupler, so that when the optocoupler is off it calls for less current in the loop, ...


3

Add a CMOS logic gate after the optocoupler/R2. That will buffer the output and the voltage will be more accurate and the time constant will be the same for on vs. off. split R4+R3 approximately evenly (11K-ish) and put the capacitor to IRET in the middle. You're not really filtering the current input well by putting the capacitor where it is. The time ...


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Does modern fiber in homes (or businesses) send enough physical signal from cross-talk to be usable in some way? Fiber to the home (FTTH) /to the premises (FTTP) is typically a passive optical network (PON) – i.e. you and all your neighbors get every neighbor's downlink through passive splitters (if you remember the ethernet hubs: like that). On the uplink,...


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If I'm understanding this correctly, this means that after some fiber station de-muxes the signals, the signal that gets sent to someone's house has some "noise" that is actually cross-talk from someone else's signal. This refers to sense wavelength division multiplexing on undersea cables where huge numbers of channels are multiplexed into a common fiber ...


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