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Current XFMR

Quoting DELCOKEVIN-at-aol-dot-com (Kevin M. Conkey):

> I am looking for a current xfmr for measuring my system 
> current. I have looked through my surplus catalogs to no avail,
> and swap meets around here are non-existent. Does anyone have 
> one of these they would like to sell (Scotty says they run 
> about $5-$15). Or, does anyone know where to obtain one.

They are out there, but you are going to have to call the surplus
guys and ask. Two places to call:

MARLIN P. JONES & ASSOC. INC.
P.O.BOX 12685, LAKE PARK, FL  33403  USA
Fax: 800-4329-9937, Fax: 407-844-8764, Tel: 407-848-8236

JOHNSON SHOP PRODUCTS; PO BOX 160113, CUPERTINO  CA  95016
Tel: 408-257-8614   Fax: 408-253-6228
Inductors; Current Transformers; Ferrite & Iron Powder Toroids,
rods, & "boxes" for RF chokes; relays; circuit breakers, etc..

MARLIN used to stock the 60:1 current transformer I currently use
(you can't avoid some puns) in my power cabinet for $12.00. They
also carried 10:1, 20:1, & 40:1 current transformers with
matching meters. I'd bet they still have a few, but they don't
list items in their catalog when they drop below "n" number of
pieces in stock. Call them, talk to (and get the name of) a
stocker/sales person and explain exactly the combination you
need. Leave your number, have them look, and call them back. I'd
bet they can put together a panel-meter/current-transformer set
right off the shelf for less than $40.00.

JOHNSON is another good bet for 0-100+ Amp panel type current
transformers. They have a large selection of Iron powder and
Ferrite RF choke cores in many different shapes and sizes. They
also used to stock the specialized current transformers Richard
Hull was referring to for $38.50 each (Pearson Model 2100) useful
for measuring Tesla tank circuit currents/waveforms. The signal
feed on these comes out through a 50 ohm BNC coax terminal direct
to the scope input. The rating on this little gem will have a few
drooling: 

Sensitivity:  1.0 V/A, 1% accuracy
Output resist.  50 Ohms
Max. pk current  500 amperes
Max. rms current  7.5 amperes
Droop rate  0.08 %/usec
Usable rise time  20 nanoseconds
Max Current-time product  0.005 A-sec
Low freq. 3 db  125 Hz
High freq. 3 db  20 MHz
I/f  0.017 peak Amps/Hz
Connector  BNC-F(UG-290A/U)
Operating Temp  0 to 60 C
Pearson List Price: $700.00
Wt = 1.5 lb.

Who knows, they still may have one left...

> R & D ELECTRONICS; 1224 PROSPECT AVE., CLEVELAND  OH  44115
Similar surplus, relay-contactors, iso-transformers, HV wire.

R&D has probably moved. I don't have a phone number. They would
be a good third choice bet for this type instrumentation. If
anyone contacts them and get's a new address/phone I will add
them to my references file.

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12