This is my attenuator circuit?
First circuit have most of you properly seen before, it's a version of the lightspeed attenuator.
My attenuator uses the H11F3M but I could not find the right symbol
As you can see it have a double pot to adjust the two optocouplere, one up and one down in voltage/curren exactly as the LightSpeed.
I have three questions:
1) Does it work when pot are added?
2) That pot would I really like to mount on the second drawing, so it have exactly same function as on the LightSpeed. Turn U3 and U5 up while turning U4 down.
I expect that RV2 shall be removed and the pot placed instead but how?
3) Last thing is that I would like the second circuit to work with 10V and not 15V as now.
First circuit have most of you properly seen before, it's a version of the lightspeed attenuator.
My attenuator uses the H11F3M but I could not find the right symbol
As you can see it have a double pot to adjust the two optocouplere, one up and one down in voltage/curren exactly as the LightSpeed.
I have three questions:
1) Does it work when pot are added?
2) That pot would I really like to mount on the second drawing, so it have exactly same function as on the LightSpeed. Turn U3 and U5 up while turning U4 down.
I expect that RV2 shall be removed and the pot placed instead but how?
3) Last thing is that I would like the second circuit to work with 10V and not 15V as now.
Attachments
Last edited:
No one?
From what I can see Fred from the data sheet of the H11F1M is, that max "on state" yields a min impedance of only 200ohm, not low enough, (the F3M is way too high at 470ohms), the NSL32RS2S gets down to 40ohm with it's max on state.
You will have trouble with minimum lowest volume level you can achieve.
Would be nice if they had one that get down to 50ohms, keep searching.
Nice try though, and Fred if you do get it going, ditch the name please, it's a bit too obvious, Torungular or something.
Cheers George
Last edited:
Thanks George
I have found these two component: single or double pack TLP222A or an other only single pack TLP240A : Access Denied
But expect it can only be used as a relay and have no variable restance?
Maybe it would be best to recalculate the circuit when the right opto are found?
The "name" was to illustrate what I was trying to do, a sort of hint, not a name
I have found these two component: single or double pack TLP222A or an other only single pack TLP240A : Access Denied
But expect it can only be used as a relay and have no variable restance?
Maybe it would be best to recalculate the circuit when the right opto are found?
The "name" was to illustrate what I was trying to do, a sort of hint, not a name
Pew what a task
I am not wary good at reading datasheeds but maybe I have found one that can be used.
Can one of these work?
http://www.cel.com/pdf/datasheets/ps2501al.pdf
http://micropac.com/images/DataSheet/53259.pdf
I am not wary good at reading datasheeds but maybe I have found one that can be used.
Can one of these work?
http://www.cel.com/pdf/datasheets/ps2501al.pdf
http://micropac.com/images/DataSheet/53259.pdf
and try to avoid the matching part
This will never happen, unless you use some sort of "active forced" matching system which is in the signal path, and this can over cook a weaker ldr to keep up with the others. Also then it cannot be called a passive signal path system.
Cheers George
The Lightspeed Attenuator System as it is cannot go to absolute zero volume, unless a mute circuit was designed to be switched in and minium.
With 50ohm you can just hear music on efficient speakers, with 200ohm this would be too loud even for background music.
Cheers George
okay thanks, that could even my brain understand
So even 50Ohm would in fact be to high on 100dB speakers.
No I have customers with 110db speakers and 50ohm is fine, about background level for dinner party, and it also depends if your source is 2v or not, I've seen the odd rare one putting out 4v!
Cheers George
First I am wary impressed over your LightSpeed!!
The reason for trying to change the components ware a fellow DiyAdio who said that a opto-fet would be more liniar.
So therefor my try to change it
You have a fare to long thread about the LightSpeed, So I did only read a bit of it.
But did there arrive some tricks to meke it more liniar or other things?
My wich is to put an logaritmic pot on it.
The reason for trying to change the components ware a fellow DiyAdio who said that a opto-fet would be more liniar.
So therefor my try to change it
You have a fare to long thread about the LightSpeed, So I did only read a bit of it.
But did there arrive some tricks to meke it more liniar or other things?
My wich is to put an logaritmic pot on it.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.