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Tony Hwang

Mark Lloyd wrote:

On Fri, 03 Nov 2006 21:09:20 -0000, (Chris
Lewis) wrote:

According to Mark Lloyd :

I have one 12VDC 1A power supply that is connected to 2 separate
cameras. This is a regulated supply, which was needed to reduce noise
in the video output of the cameras.

If one of them needed a different voltage, it would be possible to use
diodes (consider current here too, diodes have current as well as
voltage ratings) to drop the voltage (2 diodes in series give about
1.5V drop). If the devices have a common ground (as those cameras do),
that needs to be considered when powering multiple devices with 1
adapter.

Diodes in series is a reasonable regulator, but it might not
be good enough if the current through them varies a lot.

2 diodes in series is exactly what you have with a full-wave bridge
rectifier. I haven't heard of voltage drop varying with current.
Perhaps you could explain.
Hi,
Usual Si diode has a typical voltage drop of 0.2V across it's junction.
If you put them in series it'll be multiple of 0.2. If current
increases, you do the math acoding to the Ohm's law. Also regulator
typically comes in two different flavors. Series or shunt type.