Pump RUNNING Indication

[Charlie J]

I want to be able to tell when my potable water pump is operating. With my
old pump, I simply put a remote light in series with the B+ supply to the
pump. The new variable speed pump does not lend itself to this...I need to
sense current, not voltage. I have researched magnetic reed switches but
even a relatively large reed switch requires 70 to 80 ampere-turns to cycle.
The new pump draws about 3 to 4 amps so there would be lots of turns around
the reed switch.
Any ideas?
Thanks-
Charlie

 

[Charlie J]

Thanks to both of you...Meindert-I don't understand the notation "2k2" or
"4k7" in your post. Would you please explain?

73-
Charlie

 

[Charlie J]

"k" stands for thousand

Erik...it wasn't the "k" I was referring to, it was the numbers after the
k's.

73-
Charlie

 

[Peter Bennett]

That's the resistance that's printed on the top of all the surface
mount tiny resistors. You can't see a PERIOD that small....(c;



Larry W4CSC

The surface mount resistors I've used are marked with a three (or
four) digit code mimicking the standard colour code - a 2K2 (or 2.2K)
resistor would be marked "222", and a 10K, 103.

I think the 2K2 style notation was originally a European thing, but is
becoming better known and used in North America.