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Old 24th September 2009, 12:20 PM   #2531
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Quote:
Originally Posted by Tripmaster View Post
Hi Alan

Nothing happens...it just remains at full volume

For testing purposes I connected the attenuator to one of my integrated amps. The volume pot on the integrated is set at a moderate level, I thought I could then adjust the lightspeed to see if the volume decreases.

Am I taking the wrong approach?

Thanks

Richard
Does removing the 22R resistor cure the problem?

Alan
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Old 24th September 2009, 12:25 PM   #2532
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Quote:
Originally Posted by AlanElsdon View Post
Does removing the 22R resistor cure the problem?

Alan
No
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Old 24th September 2009, 12:34 PM   #2533
udailey is offline udailey  United States
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There should only be 3 wires involved with the pot. One comes from 5V and goes to the junction of pin 1 of gang X and pin 3 of gang Y and goes to the shunt LDRs.
Then a wire comes from the two pins tied together on gang X and goes to series LDRs and then another wire goes from two pins tied together on gang Y.
I believe you have GND involved with your pot and that wiring is incorrect.
Also, skip the series resistor til you get it running. If you have a great impedance from the attenuator then no resistor. If you have to low of impedance then use a trimmer in series and go from ~10R to 30~ and see what you like then order that value of resistor and replace the trimmer.
Uriah
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Last edited by udailey; 24th September 2009 at 12:38 PM. Reason: 1 of gang X and pin 3 of gang Y and goes to the shunt LDRs
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Old 24th September 2009, 12:36 PM   #2534
udailey is offline udailey  United States
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Also, placement of your series resistor is incorrect. It should be between 5VDC power supply and the junction of pins 1 and 3 rather than between the pins.
Uriah
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Old 24th September 2009, 03:57 PM   #2535
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Thanks Uriah

I'll draw a quick sketch of the circuit this evening and post a copy on the forum.

It might be a little bit easier to follow

Richard
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Old 24th September 2009, 04:51 PM   #2536
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This is how I have the pot wired

Click the image to open in full size.
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Old 24th September 2009, 05:03 PM   #2537
udailey is offline udailey  United States
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Try just removing that resistor from the pot.
I see what you did with the pot now and that should work minus the resistor.
Uriah
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Old 24th September 2009, 06:07 PM   #2538
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Originally Posted by udailey View Post
Try just removing that resistor from the pot.
I see what you did with the pot now and that should work minus the resistor.
Uriah
Hi again

I've removed the resistor, but still no joy.

I'll just check the board again
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Old 24th September 2009, 08:10 PM   #2539
Puffin is offline Puffin  United Kingdom
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Quote:
Originally Posted by udailey View Post
Also, placement of your series resistor is incorrect. It should be between 5VDC power supply and the junction of pins 1 and 3 rather than between the pins.
Uriah
I have mis-understood where the resistor should be put. It should go between the 5v+ and the 5v connecting point on the pot pins?
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Old 24th September 2009, 08:15 PM   #2540
udailey is offline udailey  United States
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If you use a series resistor at all, which can be helpful but is NOT necessary, it should go between your power supply on the positive line and the power input to the pot.
Uriah
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