| Electronics > Beginners |
| Need little help to attenuator scematic and does it work? |
| (1/1) |
| FriedMule:
I have designed an attenuator, why so complicated?... Just to learn something and to use it later on:-) My design is as I always do it, serch the net, grap scematics and combine them. I really hope that you will help me with these three questions: 1) Am I right by thinking that the double potentometer (1_out) shall on (+) and 2_out shall on lead_to_u4? 2) Can it work on only 10 volt or shall some of the values be changed? 3) Last question wil it work as an complicated liniar optoisulated attenuator? Kind regards |
| basinstreetdesign:
What do you want to accomplish with this circuit? I see no input to it. --- Quote from: FriedMule on June 29, 2018, 09:54:35 pm ---1) Am I right by thinking that the double potentometer (1_out) shall on (+) and 2_out shall on lead_to_u4? --- End quote --- I don't know what that means. Do you mean "connect (1_out) to +15V, connect (2_out) to lead_to_U4"? --- Quote from: FriedMule on June 29, 2018, 09:54:35 pm ---2) Can it work on only 10 volt or shall some of the values be changed? --- End quote --- Until I know what you want to do with this circuit I can't say. --- Quote from: FriedMule on June 29, 2018, 09:54:35 pm ---3) Last question wil it work as an complicated liniar optoisulated attenuator? --- End quote --- I dont think so as it stands. But if you could make your intentions clearer then I might be able to give you a better answer. It seems that you have an oscillator. If for some reason the output of the op-amp goes high enough to turn on the two opto-isolators U3 and U5 then U5 would pull the non-inverting input of the op-amp low. So its output would then go low, turning off the optos. This allows the non-inverting input to the op-amp to be pulled high by R5 causing the action to repeat. C5 and R13 merely serve to slow the rise and fall of the op-amp down. The pot RV3 may change the duty cycle. That is what I see. |
| FriedMule:
Thank you for your answer, sorry I did explain it badly . This is an attenuator where the audio signal goes from Filter_+ trough U3 and out to Preamp_Out_+ So the U3 act as an electronic pot, managed by the amount of voltage/current that goes trough the LED Since the H11F3M is not perfect linier, the LM358A do compare U3 and U5 and adjust the U3 so it act much more linier. When the U3 goes down in resistance, the impedance do also go down, to compensate a bit for that, the U4 goes up in value, so that the total impedance value are about constant. Yes I did mean "connect (1_out) to +15V, connect (2_out) to lead_to_U4" :-) Hope that this is a bit better! :-) |
| FriedMule:
No one? :-) |
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