From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: Voltage regulation and current limiting
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
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Andy Collins (acollins@uclink.berkeley.edu) wrote:
: One not-so-quick question to throw out there for you guys...

: For our class project, we need to design and build a power supply
: to the following specs:

: Voltatge:  adjustable from 1-12V
: Current:   *limited* at 1A

: Voltage must stay within 2% of designated value for I from 0-1A
: AC ripple less than 5 mV (rms)

To decide which kind of circuit you must know the initialprecission of
the limiter-current and the allowed temp-drift.

In the first case, you can use a Ube of a transistor as a voltage-reference
of about 0.7 VDC with a temp-drift of 2mV/K. In the second case its better
you use a bandgap-ref and a opamp-circuit to detect the maximum-current.
The output of this opamp controlls the outputstage to limit the current.

Bye Thomas
