ISOLATED AC CURRENT MONITOR
This circuit uses a small AC current transformer
from Magnetek to produce an isolated voltage
proportional to the AC current in the primary
winding. The transformer contains a single turn
primary with a low 0.001-ohm resistance. It can
easily handle 30 amps of AC current and provides
at least 500vac of isolation. With the
components shown, the output AC voltage is
scaled so 1 amp of current produces 100mv of AC
voltage. |
Everything you wanted to know about wideband,
low-frequency transformers:
EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit.
|
External Isolation Transformer Box: designed
for Mackie and other Mixers Eliminates RFI
Problems |
Grounding & Shielding: describes basic audio
transformer uses like balanced in/out and signal
splitters |
High CMRR Balanced Interface: Uses for
Crystal18 or20 Bit A/D Converters. This is a
PDF file |
High Output Line Driver for Single Ended Power
Supply: PDF file |
IC Mic Preamp uses Jensen Twin Servo topology:
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Interconnection of Balanced & Unbalanced
Equipment: 4 page booklet in PDF format
|
Internal Modification to Mic Inputs of the
Mackie 1604 Mixer Eliminates RFI Problems:
adding transformer isolation increases common
mode rejection and eliminates RF interference,
PDF document |
Isolation Transformer Passes millihertz Signals:
EDN-Design Ideas |
IT 4 Four Channel Isolation Transformer unit:
audio signal isolation transformer, product
datasheet with circuit diagram in PDF format
|
IT one inline 600 / 600 Ohm Line Transformer:
audio signal isolation transformer, product
datasheet with circuit diagram in PDF format |
Jensen Direct Box Transformers: data sheets
have example circuit diagrams
|
Jensen Transformers Application Schematics:
includes many microphone preamplifier related
|
JP 11P 1 Input Transformer Improvement for
Electronically balanced Input:
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JS 11SPP 6M 600 Ohm Line Isolator with Line
termination Switch: for used with long 600
ohm lines that need termination
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JS 11SSP 6M 150 Ohm Line to 600 Ohm Load
application: isolation transformer with
impedance conversion |
JT 10B D Used in Line Level 2 Way Splitter /
Isolator: active line level splitter circuit
with input and output isolation
|
JT 10KB D & JT 6110K B "Pro" to "Consumer"
Interfaces: from +4dBu balanced output to
-10dbV consumer equipment input
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JT 10KB D & JT DB E Provide "J Box" Consumer to
Studio Interfaces: from -10dBV unbalanced
to150 ohm balanced microphone level -45dBu
signal and from +4dBu balanced signal to -10dBV
unbalanced signal |
JT 10KB D Isolates & Converts Speaker Drive to
Line Level: |
JT 11 BM High Level Differential IC Output Stage
with DC Servo: |
JT 11 BM High Level High Current Differential
Output Stage with DC Servo:
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JT 11 DM Basic Hum Stopper Transformer Isolation
Box: simple isolator for 600 ohm balanced
audio lines |
JT 11 DM Converts Unbalanced Output to Balanced:
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JT 11 FL Isolates & Converts Guitar Amp Speaker
Out to Line Output: |
JT 11 FL provides Isolated Line Output from
Guitar Amplifier: |
JT 11 YZPC in Unbalanced Long Line Driver /
Isolator: |
JT 11B 1 + "Phantom" Buffer Provide Balanced
Guitar Output: |
JT 11P 1 as "Phase Splitter" with Symmetrical
Outputs: |
JT 11P 1 Balanced Tube Line Input Stage:
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JT 11P 1 Conversion of Unbalanced Input to
Balanced: |
JT 11P 1 in 2 Way Passive "Guitar Splitter":
from one guitar to2- guitar amplifiers
|
JT 11P 1 in 4 Way Active "Guitar Splitter":
from one guitar to up to4 guitar amplifiers
|
JT 11P 1 Unbalanced Automotive or Consumer
Application: isolation transformer box for
unbalanced consumer audio line signals |
JT 11P 1 used as Unbalanced Polarity Inverter:
passive transformer based audio signal inverter
circuit |
JT 11SSP 6M 600 Ohm Line Isolation Application:
isolation transformer for 600 ohm balanced audio
line |
JT 11SSP 6M as Input Transformer for Crystal
CS5367 A / D Converter: transformer balanced
passive input circuit for CS5367 A/D converter,
PDF file |
JT 11SSP 6M Bi-Directional Lo Z Long Line
Application: this circuit isolated and
impedance matches less than100 ohm source to
long cable line and that to over10 kohm input |
JT 11SSP 6M Passive Stereo Matrix for M S Mic
Technique: |
JT 11SSP 6M Universal Patchbay Isolation
Application: for use with professional low
impedance sources and high impedance loads |
JT 123 BL High Level Low Impedance Differential
Output Stage with DC Servo:
|
JT 123 S Line Driver with Feedback Around the
Transformer: |
JT 13K6 C in Simple 1 IC Stage Mic Preamp:
15KB PDF |
JT 16 A Improves Performance of SSM2017 Mic
Preamp IC: |
JT 6110K B at Input Stage for Crystal a to D
Converters: high performance transformer
balanced input stage for Crystal A/D converters,
PDF file |
JT 6110K B Isolates "70 Volt" Line & Converts to
Line Level: |
JT DB E "Direct Box" for very High Level Signals:
takes high level line signal and outputs
balanced microphone level signal
|
JT DB E Converts Consumer Stereo Inputs to Mono
Balanced Mic Output: |
JT DB E Full featured "Direct Box" Application
Schematic: |
JT DB E Standard Musical instrument or
Synthesizer "Direct Box":
|
JT MB C "Real" Mic Inputs & Phantom Power for
Sony DAT: |
JT MB C in Low Noise, High Isolation Line
Receiver for Low Z Sources:
|
JT MB C Isolates both Mic & Line Inputs of
inexpensive Mixer: |
JT MB C Mic Input Isolation for Mackie Mixers:
|
JT MB C Used to "Phantom" Power the Realistic
PZM Mic: |
JT MB D Converts 600 Ohm Unbalanced Mic to 150
Ohm Balanced Mic Line: |
JT MB D Passive Stereo Matrix for M S Mic
Technique: |
Method sets voltage in multiple-output
converters: EDN-Design Ideas / PDF
contains multiple circuits - scroll to find this
circuit. |
Mixed Feedback Drive for Audio Output
Transformers: Technical paper from Lundahl
Transformers in PDF format |
Power Supplies & Transformers: Basic
structures of power supplies
|
Power Supplies and Regulators: new low
power discrete switcher |
Step Down Rectifier makes a Simple DC Power
Supply: 04/09/98 EDN-Design Ideas - A
simple and useful nonisolated rectifier features
voltage step-down operation, acceptable Class A
line-current harmonics, inherent short-circuit
protection, and, optionally, a regulated output
|
Theory & Construction of Mic "Splitters": 5
page booklet in PDF format
|
Transformer Coupled Splitter: Active
amplified transformer isolated signal splitter
that enables hum-free connection of1-guitar to
more than1-amp as well as having a direct
output |
Transformers for Audio Interfacing:
Discussion on using audio transformers in
equipment interconnections, read also Line-level
transformers in High-End Audio |