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Recent content by Heydave
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energy required to produce 100W photovolatic panel
PV by itself is still a ways off because it is not just the cell technology cost to consider. Location, support and protective structures and energy conversion are also issues even if you assume no storage. The electrical grid can be treated as a storage medium, just think of the money...- Heydave
- Post #4
- Forum: Electrical Engineering general discussion
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The toughest high tech problem I have!!!
DLP is a projection technique using micromirrors to steer and focus light for display. Projectors for use with computers in presentations are available now for under a few thousand. A few large movie theaters use the technology instead of film and the picture is quite a bit better than the...- Heydave
- Post #7
- Forum: Computer engineering general discussion
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The toughest high tech problem I have!!!
It sounds as if you need a custom implementation of a DLP based rear projection. Depending on size, you may also want to sectionalize to keep the depth under control and maintain sharpness and resolution. Assuming there is some border around the table, the tapered edge you can get from...- Heydave
- Post #3
- Forum: Computer engineering general discussion
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DSL speed for dial-up
The DSLAM does not have to be a bottleneck as it is a head end system presumably located near very fast data links. It is a deployment decision to serve the DSLAM with limited backbone. Cable systems use coax but it is shared with other users as well as TV and FM channels. Multiplexing is done...- Heydave
- Post #7
- Forum: Computer engineering general discussion
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Voltage Spikes in Integrator CKT
It comes from the type of output stage amplifier circuit in the op amp. When polarity changes, one set of drivers switches off and the complement switches on. The design of the op amp determines how well this is done. Any overlap results in a short across the opamp power supplies so instead...- Heydave
- Post #4
- Forum: Circuit design
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DSL speed for dial-up
DSL uses two frequency bands above the voice band on the phone line but these signals do not go through the voice switching system. The lower band is for upload data and the upper band is for downsteam. DSL requires a modem, filter, and router at the head end which is usually at the central...- Heydave
- Post #5
- Forum: Computer engineering general discussion
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DeltaV DI 8 channel 120V AC Isolated induced voltage problem
It sound as if you have a ground loop. My guess is that there are unbalanced 3 phase Y circuits or undersized single phase branch circuits dumping current into ground. Do your switches and sensors share a common ground or return? They shouldn't nor should the signal return conductors and signal...- Heydave
- Post #2
- Forum: Electrical Engineering general discussion
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driving transformer primary
I think I first saw the idea used for data transfer in some data aquisition modules I beleive from Burr-Brown many years ago. I have not seen the technique used anywhere else nor for power but that does not mean it does not already exist. Any mismatch in the driver signals, coupling caps, or...- Heydave
- Post #21
- Forum: Circuit design
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Could a PLL do the job ?
I did a circuit like this to avoid impulse noise on a digital telephone. I ran a 4046 PLL at a multiple of the primary pulse rate and used the feedback divide counter states to open and close a sampling window to maintain a frequency lock. Errors that made a pulse early or late were limited to...- Heydave
- Post #11
- Forum: Circuit design
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driving transformer primary
If your isolation requirement is primarily DC, you can dump the transformer and use a complementary drive to matched caps. On the "secondary" side, use a schottky bridge to get back to DC. This should be good for a few ma. If necessary, use a common mode choke to filter the residuals and...- Heydave
- Post #19
- Forum: Circuit design
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Reverse engineering of an Altera PLD ?
Most programmable logic chips have security bit that once programmed, the program cannot be read out. These can be defeated but only with great effort and physical destruction of the chip.- Heydave
- Post #5
- Forum: Circuit design
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ESD immunity help!
ESD travels on surfaces and prefers edges. It really does not matter is have to be a conductor. Almost any continuous surface will block it. One way to use a four layer board is to put the planes on the outer layers and the traces internal. This clearly does not work for surface mounted...- Heydave
- Post #5
- Forum: Circuit design
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Speech Synthesizer Chip
I have done similar things using 1 bit oversampling and some sort of filter. The trick is not the output but the recording of the voice. The technique I have used is to translate .WAV files to the necessary bit stream. This allows for easier recording and editing of a recorded vocabulary. To...- Heydave
- Post #2
- Forum: Communication & signal processing engineering
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Best device for low power DC current generator
A "brushless" motor will not work. The replacement for brushes used to commutate the armature current are solid state switches designed only to switch current into the motor. The power level and voltage you mention is approximately that of an automotive alternator or generator. The...- Heydave
- Post #2
- Forum: Electric motors & generators engineering
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120VAC Led Array
I just referenced this circuit for LEDS in another post: http://www.inventgineering.com/LEDdriver.htm Use this behind a full wave bridge and cap to feed the LEDS. The strings of LEDS should be longer than my example circuit but the advantages of this over simple dropping resistors is a constant...- Heydave
- Post #6
- Forum: Circuit design
