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Three Phase Circuits
Last Updated on:
Friday, March 12, 2010 12:07 PM |
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Links to electronic circuits, electronic schematics, designs for engineers,
hobbyists, students & inventors:
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$5 junkbox Circuit Determines Phase Sequence - 04/23/98 EDN-Design Ideas:
[Note: File contains multiple circuits scroll to find this circuit.] Have
you ever wondered which way a blower motor is going to turn when you plug it into anor
socket, or have you ever inherited task of modifying three-phase wiring in your
plant? circuit in Figure 1 is a simple, approximately $5 phase.....(design idea
added 11/05) |
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60 Hz modulator records process variables - 02/16/98 EDN-Design Ideas: The
circuit in Figure 1 allows you to record process variables (4 to 20 mA,0 to 10V dc)on
a three-phase power monitor designed to record only ac waveforms. Many of se recorders
have a seventh channel, normally used for recording neutral current, which you can use
as a process-variable input. The circuit operates.....(design idea added 11/05) |
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Circuit eases three phase monitoring - 12/17/98 EDN-Design Ideas:
Measuring line-to-line voltages in a delta-connected three-phase system can present
special problems. Because all three lines may be floating several hundred volts above
ground, you can not use nonisolated, grounded oscilloscopes or other single-ended
instruments. Special isolation amplifiers are available for oscilloscopes.....(design
idea added 6/06) |
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Inverters form three phase VCO - 08/02/01 EDN-Design Ideas: You sometimes
need an inexpensive VCO that can produce evenly spaced three-phase outputs over a wide
frequency range. You could use tracking all-phase filters with only one oscillator,
but this technique is difficult to implement and offers limited range. Other methods,
such as using a DSP, are feasible, but they're complex and expensive.....(design idea
added 1/05) |
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Level shifting nixes need for dual Power Supply - 01/06/00 EDN-Design Ideas:
The AD736 true-rms-to-dcconverter is useful for many applications that require precise
calculation of the rms value of a waveform. This converter can determine the true rms
value, the average rectified value, or the absolute value of a myriad input wavefo.....(design
idea added 09/05) |
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Optocoupler simplifies Power line monitoring - 01/10/02 EDN-Design Ideas:
The use of a linear optocoupler and a capacitor-based power supply yields a simple,
yet precise power-line-monitoring system. The circuit in Figure 1 converts the 110V-ac
power-line voltage to an ac output voltage centered at 2.5V, covering 0 to 5V. The
circuit isolates the output signal from the power line.....(design idea added 1/05) |
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RF Transmitter uses AMI encoding - 11/24/99 EDN-Design Ideas: Although
alternate-mark-inversion (AMI)encoding is well-suited for direct-conversion FM
transmission, designers often overlook the technique. AMI, a three-phase,
synchronous-encoding technique, uses bipolar pulses to represent logic ones and no
signal to.....(design idea added 8/03) |
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Self modifying code extends aDDRessing mode - 12/17/98 EDN-Design Ideas: As
just about any assembly-language programmer knows, self-modifying code (SMC)is usually
undesirable, unintentional, and destructive. However, the SMC routine in Listing 1 is
extremely useful to extend the indexed, 16-bit offset addressing mode of the venerable
HC05 µC from 8 bits,.....(design idea added 08/05) |
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