As I told previously, and trying to be grateful I want to share the idea of a digipot who could be used in different scenarios, adjusting input and output to different ranges.
It selects a digit and close a relay, just one, depending on voltage input. (I shared the bidir-switch with transistors but it only works on some circumstances) The way of selecting resistors on input and output could be used to linearize or maybe on the oposite, to give a logaritmic output, but as it is now can be used as a digipot, as it gives a variable resistance proportional to its input and to the resistors at output, without serial conversions.
Isolation and power depends on the selected relays.
In this configuration is a resistor divider with same value resistors of 5.7K, feeded with 12 V, giving an output between 0-335 mV, not linear, as correspond to a divider, (about 0,110,125,140, 135, 165, 225, 335 mV), but it instead could handle different circuits each one. It can grow on steps or be shrinked. Yes it is a pour resolution, but it has some other advantages.
The leds are just to see it better, but can be omitted. I was told the cmos buffers can be replaced just inverting the feeding voltage to comparators. anyway they are just two chips.
The circuit is about 15 dlls so it can be affordable for many and may be useful to somebody.
For instance and just dreaming as an alcoholic mind (I don't drink it), if the temp. would be someway fixed and pressure would be the proportional input, it could handle the valves for different distillation stages.
If somebody has a simmilar functionality but with a better circuit and want to share it, it is welcome.
Thanks Brian for all your attentions. Thank you to other who gave me your time. I will make the previous circuit phisically and then will tell you how it worked, in about one week I'll have it. (A friend of mine with some little help from me have finished a cnc drilling machine to make the circuits and we will use it to do it just after we deal with a little of backslash and few losen steps)
If there is another way to help, please tell me.
Sincerly
Luis J. I.
I hope you some day get proteus so you could see same simulations, but the fact you don't have it makes me think that you have something better, what is it?
Is there something like a "circuits bank"?
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I was forgetting to send the graph of response of the corrected circuit in the input of the moc. It is here.
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Correcting: The input has a 4.2 V as offset and a variation of 0.75 mV. is there a way to make shorter the offset and bigger the real input or at least increase this last? (Volt_a_pot4b.png)