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Old 18th May 2012, 06:54 PM   #4671
maximus is offline maximus  Scotland
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Default VCCS control

JMNSHO,

The VCCS module described way back in this thread was designed for constant current control and provides 65 levels of current via a digital potentiometer. Operationally this is fine enough to get the volume to the required level. The range of operation can be adjusted to suit the system by changing the current setting resistors. It was originally designed as a group buy, for DIY use, driving George’s Lightspeed configuration. There is space on board for the LDRs or you can hard wire the LDRs off board. Uriah Daily can provide matched LDRs for this module. The VCCS module can provide volume and balance and it works very well. With matched LDRs the balance control may seem redundant but in practice it is useful for balancing out channel differences in the music source or those caused by less than ideal loudspeaker placement. Control is via push button either on the chassis front panel or/and via the matching remote control transmitter and receiver modules.

The PCB’s or built and tested modules are still available and the prices are still the same although the shipping cost has increased slightly since the prices were originally published.

High performance shunt regulators for the VCCS reference chain and an ultra low noise series regulator for the main regulator are also available to provide first class supply and control regulation. These regulator modules are easily fitted to the VCCS module.

Regards
Paul
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Last edited by maximus; 18th May 2012 at 07:05 PM.
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Old 18th May 2012, 06:57 PM   #4672
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JMNSHO, BFNY and others: smart ideas.
FWIW, my experience of the CCS on the LDR was fantastic and I would be very keen to pursue it further.
I would echo JMNSHO's sentiments that it should possibly be explored in a new thread.
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Old 18th May 2012, 07:22 PM   #4673
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Quote:
Originally Posted by Dr.H View Post
JMNSHO, BFNY and others: smart ideas.
FWIW, my experience of the CCS on the LDR was fantastic and I would be very keen to pursue it further.
I would echo JMNSHO's sentiments that it should possibly be explored in a new thread.
For the record: JMNSHO = Just My Not-So-Humble Opinion

Signed, Wapo54001
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Old 18th May 2012, 07:38 PM   #4674
BFNY is offline BFNY  United States
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here's my proto board - as you see, this can be done in a very small space.

This uses dual rail to rail op-amps and 4 BS170s. The board is about 3" long

Mods can move this to a new thread if desired, or I can repost in a new one.
Attached Images
File Type: jpg VCCS prototype.JPg (114.4 KB, 368 views)
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Old 18th May 2012, 07:49 PM   #4675
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Quote:
Originally Posted by BFNY View Post
here's my proto board - as you see, this can be done in a very small space.

This uses dual rail to rail op-amps and 4 BS170s. The board is about 3" long

Mods can move this to a new thread if desired, or I can repost in a new one.
Good looking board! That looks like it could be what I was talking about earlier -- a board that lots of people could build and enjoy, and featuring tighter control of the LDR resistances.
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Old 19th May 2012, 02:41 AM   #4676
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Quote:
Originally Posted by BFNY View Post
here's my proto board - as you see, this can be done in a very small space.

This uses dual rail to rail op-amps and 4 BS170s. The board is about 3" long

Mods can move this to a new thread if desired, or I can repost in a new one.
BFNY, I'm glad a saw your board. I just realized that I'd added a lot of complexity to my design to solve a problem, and then solved the problem with a simple change to the circuit but then never went back to get rid of the unnecessary complexity I'd added! I need to test to verify, but I think my design just got a whole lot simpler thanks to seeing your board!
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Old 21st May 2012, 09:13 AM   #4677
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BFNY is that the VCCS LDR pre? Group buy or could you share pcb plans?
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Old 21st May 2012, 06:45 PM   #4678
BFNY is offline BFNY  United States
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Still playing with the board layout and design. Will post in another thread when ready to go.
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Old 21st May 2012, 08:21 PM   #4679
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Quote:
Originally Posted by maximus View Post
The PCBs or built and tested modules are still available and the prices are still the same although the shipping cost has increased slightly since the prices were originally published.
Paul,


Where can I get some more info on this version?

Schematics, theory, pcbs, etc.?


Carlos
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Old 21st May 2012, 08:37 PM   #4680
maximus is offline maximus  Scotland
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Hello Carlos,

All the technical information is available in the Lightspeed thread.

The VCCS and remote control module photos are shown on post 1874 page 188.

The circuit schematics are shown on post 2728 page 274.

The module prices are shown on post 1804 page 181. These prices are still the same except that, after losing a few shipments, I now ship only with an insured service and the prices for shipment are higher. I can quote for specific destinations.

Regards
Paul
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