Using positive rail as chassis ground
Using positive rail as chassis ground
(OP)
Hey all. I have an interesting question:
I am making a very low budget piece of electronic equipment for mass production. We have circuits on two separate boards and it occurred to us that we could save big $$$ by sending Vcc (5VDC) to the second board from the first ***through the chassis*** (saving us a difficult wiring job).
I have seen people use the positive terminal of a 9V battery as chassis ground before. I am wondering if there is any reason I can't use a regulated 5V for chassis ground (the circuit is somewhat sensitive to radiated EMI).
What say you?
I am making a very low budget piece of electronic equipment for mass production. We have circuits on two separate boards and it occurred to us that we could save big $$$ by sending Vcc (5VDC) to the second board from the first ***through the chassis*** (saving us a difficult wiring job).
I have seen people use the positive terminal of a 9V battery as chassis ground before. I am wondering if there is any reason I can't use a regulated 5V for chassis ground (the circuit is somewhat sensitive to radiated EMI).
What say you?





RE: Using positive rail as chassis ground
RE: Using positive rail as chassis ground
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Using positive rail as chassis ground
RE: Using positive rail as chassis ground
As another example of this type of setup is a diesel engine driven firepump, where positive (chassis) grounded systems are semi common.
RE: Using positive rail as chassis ground
RE: Using positive rail as chassis ground
Save a foot of red wire, add a foot of black wire.
RE: Using positive rail as chassis ground
Dan - Owner

http://www.Hi-TecDesigns.com
RE: Using positive rail as chassis ground
RE: Using positive rail as chassis ground
Using the chassis as a power rail is BAD; don't do it. The reasons are legion:
> Introduction of noise into the circuitry. The chassis is basically a giant antenna, and will pick up more noise than a wire will.
> Someone touching the chassis will add more noise, because people make good antennas as well.
> People are also great capacitors, and as we head into winter, electrostatic zaps to the chassis will go into the circuitry and possibly damage the transistors
> Non-ground chassis' may contact real grounds, thereby causing lots of sparks, damaged power supplies, and a fire hazard
nuf said?
TTFN
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