> -----Original Message-----
> From: Richards
> Subject: Re: [TenTec] Station power supply??
>
> Is this notion of bonding the V- to chassis in any way
> related one could get shocked when touching the
> chassis of an old Halicrafters tube sets?
Think of it like this:
E = I * R (Ohm's Law)
Whenever you have current flow in a conductor of greater than zero
resistance, you will have voltage drop. The voltage at one end of the
conductor will be greater than the voltage at the other end. The smaller or
longer the conductor, the greater the resistance, and the greater the
voltage drop for a given amount of current.
The object of bonding two points is to equalize the electrical potential
(voltage) between those two points. If there is current flowing in the wire
intended to bond the two points, there will be a voltage drop in that wire,
and the two points CANNOT POSSIBLY be at the same electrical potential. It
would be a violation of Ohm's Law.
Current flows in both the positive and negative conductors connecting your
radio to its power supply. If the bonding wire is placed in parallel with
the negative conductor, some of that current will then travel through the
bonding wire, causing a voltage drop in that wire, and guaranteeing that the
chassis of the power supply will be at a different electrical potential
(voltage) than the chassis of the radio. This difference increases if the
current is increased, or the wire length is increased, or the wire gauge is
reduced.
In practical terms this may or may not matter. But if you want two pieces of
equipment to be at the same electrical potential, the bonding wire
connecting them CANNOT be a current carrying conductor.
Chuck N4XS
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