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Basically what I am after is some sort of a circuit which will amplify higher voltage signals, but possibly dampen lower voltage signals, in order to make a wider separation between high and low voltage. This is just for a little DIY project I am working on at home, and basically it would be comparable to setting your audio equipment to "Theater" mode vs. "Quiet" mode. Would this be easily accomplished with a fairly simple circuit, or am I trying to go after something far too complex for a beginner?

What would be the name of a circuit similar to what I am attempting to build?

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    \$\begingroup\$ Yes, an expander. That seems to be exactly what I am looking for is a "Dynamic Range Expander" circuit. \$\endgroup\$ – Sean Nov 29 '11 at 4:17
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What you are describing is an expander. This performs the opposite function of a compressor.

Basically, it is a amplifier (or simple attenuator, see below) circuit set up so that the gain is controlled by the incoming signal level. There are various ways of implementing this in a circuit, from simple to very complex. Here is an example of about the simplest compander (compressor/exander) circuit using a light dependent resistor and LED to control the attenuation:

Basic Compander

Here is the page of articles/schematics this came from which includes the explanation of the circuit and various other similar circuits. Google will turn loads more up.

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It sounds like you're after some kind of expander circuit, which is half of a compander. There are many example circuits available online, with a great deal of them around the NE571 or NE572.

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    \$\begingroup\$ How about you add an example to your answer? We want to be the source of content not a place to find links. This helps down the road when people find this question from searching the web and might end up finding all of your links to be dead. \$\endgroup\$ – Kellenjb Nov 29 '11 at 15:41

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