Need documents about digital automatic levelling control (ALC)

[erickang_pro]

Hi, I found a lot of materials on analog ALC, however, there is no materials on digital ALC.
Does anyone has any link to the digital ALC materials?
Thanks

 

[mumtaj]

Re: Digital ALC

The Digital ALC compensates and compresses all audio materials such as news, music, drama, sports, CM, etc. to appropriate bandwidth for broadcasting services without spoiling its original sound quality and in a natural touch to human ears, just like a professional audio mixer-man operates. As conventional limitters & compensaters change the original sound (waveform) electrically and forcibly, those processed sound programs only give unpleasant touch and feelings to its viewers and audiences.

REFER ON FOLLOWING LINK:

**broken link removed**

 

[erickang_pro]

Re: Digital ALC

Hi Mumtaj,
Sorry for not making myself clear in the forefront,
The digital ALC that I meant is digital automatic levelling control, ie the circuit used to monitor and levelling the RF power coming out from a Power Amplifier or Transmitter.
Do you have the link to it?
Thanks.

p/s:I am curious as all the materials posted in the Net are for analog ALC and there is no digital ALC documentation, so I am wondering if we have such thing as digital ALC or not.

 

[mumtaj]

Re: Digital ALC

An audio tape recorder having particular utility for retrofitting vehicles having radios, tape players, or other audio generating devices has an automatic signal level control circuit adaptable to very wide ranges of input circuit level. The circuit has a variable resistor in parallel with the audio output having a resistance level dependent on the voltage output of a digital voltage counter. The voltage counter sets out a discrete stepped output dependent on signals generated from a peak detector, which detects input signal peaks above a preset level, and a low level detector, which detects average input signal levels below a predetermined level. A delay switch prevents the low level detector from actuating the counter for a preset period.

refer on following link:

https://www.freepatentsonline.com/4424538.html