I tried using an LDR as a compressor but it was obviously too slow, "HELLo". The hell part of hello was finished before the LDR reduced the level. It was a no-name-brand Chinese one. I used a little light bulb then a fairly bright LED but I did not try an Xenon flash tube to make the LDR conduct. I do not see how positive feedback can speed up the physical part.
Claims for The Batterizer voltage booster product also use the words many, most then all then says disposable AA cells are thrown away when their voltage drops a little. They make The Batterizer and sometimes it drains a battery cell instead of making it last longer.
Hi AG,
We can always find false claims around but that certainly does not prove that every claim is false.
Positive feedback basically works by measuring the error in the output and knowing what it is supposed to be and that it is not yet that, it increases the drive. Of course this means everything else has to be right too, such as the bias, because obviously if the bias is already set high then there's nothing higher left in order to drive harder.
The audio couplers are made with fast attack, and i guess that is because that is the most wanted feature. But that's not the end of it either, because we also have to choose the range of operation carefully. For example, trying to use the entire dynamic range would lead to something even a snail would not want to listen to
But limiting the range by using say a parallel resistor (for a 10 to 1 dynamic range) will allow the overall action to speed up already. For example, 1ms to 50 percent audio attenuation. It seems to me that ought to be good enough. What do you think, does 1ms to 50 percent attenuation sound good enough to you or no?
In other words, if the device resistance spread is from 1k to 100k, we dont have to use that entire range we can use 1k to 10k (or about 900 ohms to 10k). If it takes 10ms to get from 100k to 1k then it probably takes around 1ms to get from 10k to 1k.
But i am working from theory and the spec sheets that i knew about. For the devices i have it could be totally different. As Ron pointed out, if the devices are not chosen carefully with respect to their KNOWN spec's, we can not hope to get anything useful out of it except by pure chance.
I will try to test the devices i happen to have on hand, but as noted this can not be considered an all encompassing test as these were probably the cheapie brand. The good ones are probably four or five bucks each (USD).