Pelleplutt:
Do not belive everything on the net.
CTR are important to calculate with. Look at the 4N27, 10% up to what I have seen as max, 600%.
The solution with the zeners are not optimal when the input signal varies 20 volts (60-80)
I have read earlier in this tread why the design was made like this.
Was it nessecery to let voltage in the span 0-50 volts be absolutly off.
With only a resistor, 0-10 volts can be off and over 60 on.Pelle
Hello Pelle,
I am looking into this again after some real tests i have done and I am starting to understand you point on why this could be not a good way to go.
With voltages varying so much, I am having problems choosing the components. Either they use too much power, or the resistors do not suit to all cases.
Please could you suggest another method ? Anyone else?
I will post now some simulations which are very close to what I have been seeing in real tests.
thank you very much.