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  1. Madcow

    Problem coverting a 5V analog signal to a 20 V digital signal (suggestions?)

    Check the voltage output of the LM324 board. It looks like the JDIO should accept anything over 10vdc as a high. Chech the circuit because the LM324 can run upto 32 vdc in single supply. You may have to just tweek some values on that circuit.
  2. Madcow

    USB current???

    If I remember correctly the device has to ask for the power. It asks for it in units of 100ma in 2.0 and 150ma in 3.0(usb on the go)(Up to 5 units per device). I also think the max power can change depending on the communication speed.
  3. Madcow

    need to electrically isolate LM317 TO-220 heat sink

    STMicroelectronics has an isolated package lm317p.
  4. Madcow

    Communicating with DAC via SPI

    I rember something like that when I used that DAC. I think it had something to do with not toggling the CS signal between the two commands. Also if the CS goes high before the 16th bit it aborts the command.If you switch which commands you send first does the other output work...
  5. Madcow

    2 switch flyback

    Don't forget the polarity of the transformer -200 volts should be reflected back to the primary. (Ignoring parasitics). ie. 400 volts is across the primary during the on time and -40v on the secondary (no conduction due to rectifiers being reverse biased). During the off time the secondary...
  6. Madcow

    DC Converter Needed

    you beat me to it again, itsmoked. here is another one http://www.national.com/pf/LM/LM5118.html
  7. Madcow

    Video output for microcontroller

    Either one will work, the real problem is the large amouts of data that needs to be transfered for any type of quality graphics. I would look at the imx 27 or a Davinci processor. Depends on the applications. Here are some PIC links: http://webpages.charter.net/greener/electronics/...
  8. Madcow

    Ethernet testing

    I'm going to give these guys a try http://www.iol.unh.edu/services/ Looks like I can get out of a lot of work for a reasonable price. Thx
  9. Madcow

    32 digital channels on scope

    Lecroy offers an option for 32 digital inputs. http://www.lecroy.com/tm/Solutions/MixedSignal/MS-32/default.asp Agilent and Tektronics allow some of their scopes and logic analyzers to be connected together and function as one.
  10. Madcow

    In search of a battery protector

    Google low voltage disconnect They are basicly what MacGyver said. Some have allot of features like high voltage trip and ethernet warnings. Make shure its powered off the charger/load side and not the batteries or it will drain the batteries for you.
  11. Madcow

    square wave -->sine using passive bandpass filter

    How about a D2A converter, a tone generator from a phone or an oscilator going to an op-amp with an enable?
  12. Madcow

    Low EMI with TOP246Y

    This is one of my favorites: http://www.infineon.com/dgdl/AN-EMI-01_v1-1_1.pdf?folderId=db3a304412b407950112b417bddb2406&fileId=db3a304412b407950112b417be252407&location=Products.Power_Semiconductors.DOCUMENTS.AN-EMI-01_v1-1_1.pdf Also search the major power semiconductor sites ie National...
  13. Madcow

    Looking for a Microchip MCP1727T Cross Part

    Do you need tape and reel? MCP1727-ADJE/MF says 580 ready to ship on Microchip direct.
  14. Madcow

    How does a TV make white

    Alot depends on the LED's you have. You need to check the led data sheets to find out how much light and at what wavelength the led gives off at a set current. National semi, cypress and philips have alot on leds and color mixing. Try: Bob Pease, Analog by design show Driving high power leds...
  15. Madcow

    full-bridge PFC

    You AC bridge should stop it from going back to the mains. How do you plan to draw current when the ac is on the lower part of the cycle? ie. 48 volts to 0 volts. Is the full bridge going to buck and boost? Like Scotty said a standard boost pfc can handle KWs.
  16. Madcow

    Flyback design question

    CY4 is for EMI reduction. I'm guessing that the "Y" is for an safety agency approved Y-cap. I've been told it helps cancel the primary to secondary capacitance of the transformer.
  17. Madcow

    Ethernet testing

    Thanks all. Not being a network person I have little ethernet knowledge. Do to personel cuts, I've become the resident expert. I've inherited 4 ethernet connected projects, 2 with PICs, 1 ARM , and 1 TI dsp. Currently all we do is connect them to a pc and see if the web page comes up. I think...
  18. Madcow

    Ethernet testing

    I have several embedded designs that need to be validated and tested. Is there any software or test equipment that can test the TCP/IP stack and give preformance specs. ie. connection speed, throughput, response time ect. Maybe even simulate a high trafic network.
  19. Madcow

    RS485 communications interface with PIC

    Google pic rs485 lots of stuff. Code, demo kits, ect. rs 485 is similar to rs 232 but with differential drivers. So, you may want to Google pic rs 232, or pic usart. Also check Microchip App notes.
  20. Madcow

    Simple on/off SMPS controller beats PID software control.

    From what I can tell, you are comparing two different control teqniques.The pid control and hysteretic control. Hysteretic is great for load transients. The pid control on the demo is running at about 100k. It may take several itterations to respond. It also has limit on the maximum change in...

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