[GreenKeys] Loop power supplies

[Jeffrey Angus]

On 3/5/18 7:47 AM, Nick England wrote:
> Clearly I am confused.
> What is the diff between a current regulated source and a
> constant current source?
A current regulated source sets a current for a given load.
Change the load and the current changes.
A current source, will supply a constant current regardless of
the load. Until it runs out of voltage (compliance) to supply the
current.
> Is there a corresponding diff between a voltage regulator and
> a constant voltage source? What is a 7815? A three terminal
> device that provides a constant voltage regardless of load. Isn’t
> that what a voltage source does?
LM7815, a 15 volt positive regulator.
It is the opposite of a current source.
The operation of a voltage regulator is to maintain a fixed voltage
regardless of input voltage. Up to the current rating of the input.
> If this TMC device is set for 60ma into 2000 ohms it provides
> 120v. What do you think it provides into 1000 ohms?
60 volts.  And 6 volts across a 100 ohm load.
And for each different load, you have to readjust the current.
it is NOT a constant current source. It is a regulated, for a given
load, source.


-- 
"I am a river to my people."
Jeff-1.0
WA6FWI
www.foxsmercantile.com