|
 |
DiscoverCircuits.com -- Hobby Corner
Last Updated on:
Tuesday, June 01, 2021 03:06 PM
Hobby Circuits List
The contents &
graphics of Discovercircuits.com are copyright protected.
LINK to Dave's circuit, but DO NOT COPY any files to your WEB
SITE server |
|
|
|
|
More
Display Circuits |
|
Isolated Power Supply for Digital
Panel Meters
September 13, 2008
|
|
Many inexpensive
digital panel meters, such as the one shown below, are designed
to operate from a 9v
battery. However, the nature of the panel meter internal design often requires
that the DC supply used to power the device be isolated from the ground terminal of
the panel meter’s input. |
|
|
|
This often makes it difficult to use
with a common connection between a DC power supply ground and a sensor’s circuit ground.
But, you can generate this floating voltage fairly easily using the simple circuit
below. |
 |
This hobby circuit below is powered from a 12v to 15v supply and
generates a 100KHz square wave signal, using a CMOS
version of the 555 timer.
This AC voltage is rectified and limited to +9v using a charge pump method.
The two 0.01uF capacitors maintain a floating voltage for the panel meter, so its
voltmeter ground input can also be connected to the DC power supply ground. |
|
|
|
Click on Circuit Below to view PDF of Schematic |
|
 |
|
|
|
|
