crasic

Berkeley, CA

Age: 25

I'm a physics student at the University of California.

16h
comment Diode to control the direction of current or as a switch
All the current flowing through your motor needs to flow through the diode. If the motor pulls a few Amps most "general purpose" diodes will fail quickly. Make sure you are using a large enough diode. Your simple circuit is inefficient but will suffice for your purposes, the diode needs to be large enough to handle the current.
18h
comment Explantation for fried charger with Multimeter
Ampere readings go in series with the load. The 1000ma number is the largest current you can draw from that power supply since the vast majority of commercial power supplies are designed for constant voltage output. Your multimeter will read current by placing a small resistor and measuring the voltage drop across it. If it was a 1 ohm resistor you just tried to pull 5A from your supply and something blew up.
18h
comment Explantation for fried charger with Multimeter
If you simply connected the two multimeter probes to the + and - on the supply in ampere mode you effectively shorted the power supply and probably burned it
1d
comment Intel Integrated Audio Signal Path
Integrated graphics has a analog coding chip actually generating the physical signal too.
1d
comment Intel Integrated Audio Signal Path
Integrated graphics has a analog coding chip actually generating the physical signal too.
1d
comment Intel Integrated Audio Signal Path
The Audio DSP is integrated, AC'97 is the last link to talk to a chip dealing with the analog circuitry, its basically an inteligent DAC on something better than I2C. It is also possible that the chipset integrates the DC97 and codec.
1d
comment Intel Integrated Audio Signal Path
The Audio DSP is integrated, AC'97 is the last link to talk to a chip dealing with the analog circuitry, its basically an inteligent DAC on something better than I2C. It is also possible that the chipset integrates the DC97 and codec.
1d
comment Intel Integrated Audio Signal Path
There is a dedicated audio bus on the motherboard and the controller lives on the chipset/southbridge , it is used both for audio output and modem interfaces. Audio chip is on this bus and the data is transfered in the AC'97 protocol, how the chip drives the analog circuitry depends on the device used.
1d
comment Intel Integrated Audio Signal Path
There is a dedicated audio bus on the motherboard and the controller lives on the chipset/southbridge , it is used both for audio output and modem interfaces. Audio chip is on this bus and the data is transfered in the AC'97 protocol, how the chip drives the analog circuitry depends on the device used.
1d
comment Intel Integrated Audio Signal Path
some audio codec or DSP chip that drives a small output stage, probably integrated DAC.
1d
comment Intel Integrated Audio Signal Path
some audio codec or DSP chip that drives a small output stage, probably integrated DAC.
Jun
26
comment What is an open source backup app alternative to deja-dup/duplicity that gives me more flexibility on *nix?
@Amar check out rsnapshot
Jun
26
comment what is the waveform difference between primary and secondary of transformer
The magnetic field that gets wound up with your primary current is shared higher up by the secondary winding. Magnetic fields cause electrons to move inducing a voltage. Since your primary voltage is fixed by your power company, the voltage at the top of the winding must be higher. Because the circuits on an auto transformer are electrically connected. They are less isolated and you are more sensitive to load impedance
Jun
26
comment How to amplify a very small signal
Heavy filtering before amplification. Tuned resonators and heterodynes, both can be emulated with software and a good adc for reasonable frequencies but typically you tune analog (discrete or otherwise) components as a filter.
Jun
26
comment Why does this transformer draw so much current?
I think measuring inductance would be the bare minimum for winding your own transformer. You can get cheap lcr bridges or measure yourself with a frequency generator and scope
Jun
26
comment advantages of a arduino uno waveform generator over an arbitrary waveform generator
Accuracy mostly. With a dedicated DAC and output amp you could make a decent arbitrary waveform generator. Arduino uno can control a 300khz dac without needing optimized code
Jun
25
reviewed No Action Needed Are capacitive display(s) capable of measuring what fraction of a finger is touched?
Jun
24
comment How do I sniff packets with a Zulu chip based on Si1000?
Does the IDE have any device-specific configuration options?. It may be as simple as the wrong device definitions - On Different boards the LED may not be on the same pin (or even have an LED). Without more details on the IDE and code its hard to tell. If you have an oscilloscope I would probe the pin you expect to toggle to see if there is a voltage. You can do this with a multimeter on DCV if you set the blink frequency low enough
Jun
24
awarded Citizen Patrol
Jun
24
answered What is an open source backup app alternative to deja-dup/duplicity that gives me more flexibility on *nix?
1 2 3 4 5