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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W9JN on April 26, 2016, 10:39:19 PM



Title: >> Chicago Transformer Company HV Type <<
Post by: W9JN on April 26, 2016, 10:39:19 PM
Greetings:  I have a Chicago Transformer Company transformer with the following specifications:  #95 Type 672N107, single phase, Frequency 50/60 with a primary of 220-230-240. It has the following info on the label. Section #1V 4600 CJ amps 325, Section 2V 3500 CJ amps 425, KVA 1.15, test 7500 voltage. I tried looking for info as to a schematic or other info. I think this would be a great unit for a high power amp but in most cases it would be dropped with a Variac. Any info would be most helpful.  73 John W9JN   4-26-2016


Title: Re: >> Chicago Transformer Company HV Type <<
Post by: Opcom on April 27, 2016, 02:07:41 AM
"Section #1V 4600 CJ amps 325, Section 2V 3500 CJ amps 425, KVA 1.15, test 7500 voltage"

Is it an old one and the label hard to read? The part number is not apparently a standard catalog one maybe it is from a military or third party piece of gear.

Could it be CT instead of CJ and 0.325 instead of 325?

Just to speculate if it is CT and used with a full wave rectifier:
2300-0-2300V, 0.325A = 747VA (2500VDC?)
1750-0-1750V, 0.425A, = 743VA (1900VDC?)
It's rated 1.15KVA but VA and Watts are not always the same thing. Good size transformer though.



Title: Re: >> Chicago Transformer Company HV Type <<
Post by: KA2DZT on April 27, 2016, 11:44:26 AM
"Section #1V 4600 CJ amps 325, Section 2V 3500 CJ amps 425, KVA 1.15, test 7500 voltage"

Is it an old one and the label hard to read? The part number is not apparently a standard catalog one maybe it is from a military or third party piece of gear.

Could it be CT instead of CJ and 0.325 instead of 325?

Just to speculate if it is CT and used with a full wave rectifier:
2300-0-2300V, 0.325A = 747VA (2500VDC?)
1750-0-1750V, 0.425A, = 743VA (1900VDC?)
It's rated 1.15KVA but VA and Watts are not always the same thing. Good size transformer though.


Patrick has it right, but with a choke input filter it won't make those DC voltages.  Seems both secondaries can be loaded.  Loading only one secondary will reduce the VA load, so you could use a cap input filter which will increase the DC voltage.  The higher output DC voltage has to used to figure the VA load.

You need to check if the two secondaries are separate windings or is it one winding with taps at the lower voltage.  You can do this with an ohmmeter

The RMS Test Voltage is 7500vac.  This computes to a working DC voltage of about 3250 volts.  Rule to figure working voltage is to subtract 1KV from the RMS Test Voltage then divide by 2.

Measure the DC resistance of the secondaries and let us know what they are.

Fred
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands