Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Search results

  1. 3BABY

    150 to 250V 1A Generator Circuit

    FvM, yes this could well be the reason why, if i hold the Gate of the SCR at 0V there is no problem, if i bring it up to 5V (with 500ohm resistor) quickly and then back to 0V i can generate a spark, but then i have to be very quick to turn the power off to the system or the resistor (OPTION 1)...
  2. 3BABY

    150 to 250V 1A Generator Circuit

    Hi Klaus, yes according to the datasheet ref spec and with reference to the webpage where the step-up converter was used for the Nixie tubes the 100nF was incorporated, i did not put in another polarised HV capacitor on the HV side as i thought that C4/C5 would be the capacitors on this side of...
  3. 3BABY

    150 to 250V 1A Generator Circuit

    Hi Guys, Im having a bit of trouble with a circuit. Please see schematic below. the top portion is a Capacitor Discharge Ignition circuit using a SCR, this is triggered by a microcontroller (not in schematic), the second portion is a 150-250V DC generator using a Step-Up DC-DC Controller (using...
  4. 3BABY

    150V to 5v logic converter

    Yes quite right, the later model of these CDI units did use a HV generator in the unit itself and no generator magnet/coil setup. i have pulled this one apart and it is the earlier type. Great! thanks for the explanation Brian. :-) Klaus, how about 87K resistor and a 3K resistor, this...
  5. 3BABY

    150V to 5v logic converter

    Ok Brian, i understand, forget i ever used the word "fast" .. i was simply meaning without delay. as i said before i should have been more precise. Klaus, using the 1.5M and 30K ohm resistors would give 2.94V.. im looking for around 5V w.r.t to the CDI info, the capacitor is charged via a...
  6. 3BABY

    150V to 5v logic converter

    apologies guys, was out of town for a few days following your replies. i need a digital signal out the other side. Brian,. yes i get it, it does not need to be 40000rpm fast.. just 7400 S fast or around the 5uS mark.. at least HCmos fast, i should have elaborated on what i meant by fast :-)...
  7. 3BABY

    150V to 5v logic converter

    Hi Guys, ive been scratching my head about this, have looked over the web but i cant seem to figure out what device to use. the problem: i have a 150V signal coming from a Capacitor discharge ignition system that goes into a coil to produce high voltage that goes toward the spark plug (i.e...
  8. 3BABY

    Created Symbol in Xilinx ISE Schematic editor Error NgdBuild:604

    Hi All would anyone be able to help me out, or point me in the right direction of some documentation for this, i have searched the web and read through xilinx documents but cant seem to find an answer: i have a project for targer XC9500 series CPLD, has top level shematic and a pin.ucf file...
  9. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    see this is the part that is confusing me. if the above statement is correct i have 8V at 5A going through a 0.1 ohm resistor. using P=V*I this give me 40W. but the question is.. we have 40W of power being used by "the load" doesnt that mean that the resistor should have a power rating of 40W to...
  10. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    Thanks for the reply Brian, ok so im working with a circuit with 4xLM338 with resistors values of 0.1 ohm each. this would give me a power dissipation of 2.5W when 5A is being drawn from each regulator (so i can get the full 20A - LM338 is rated for 5A) so if i choose a 0.1 ohm cement resistor...
  11. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    Thanks! ok so the question is, what Power rating can i use for the output resistor(s) if the resistance in 0.3-0.5 ohm?
  12. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    Hi Borber, thankyou for the reply! yes you are correct im fairly new to op-amps and high current power circuits using silicon and not just straight big transformers and capacitors, this is infact my first post in the Analog section on this forum. Digital electronics is where my knowledge lies...
  13. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    Hi!! thanks for the reply, i have been looking over the datasheet and i see another circuit that looks a bit better with the use of LM741. i would still like to use it for 8V 20A supply. will the LM741 work with 8V supply? also i dont understand the calculation. am i going to have to use a 50W...
  14. 3BABY

    LM338 15A Power Supply Circuit - HELP please

    Hi All, i have the below circuit, straight out of he Texas LM338 datasheet as a reference circuit, i would like to use it to build a 15-20A 8v power supply, what i dont understand from the circuit is the resistors R5 and R6 being 0.1 Ohm each. i understand that for 15A the circuit uses all 3...
  15. 3BABY

    Constructive criticism on Power Supply for Xilinx FPGA and CPLDs (attached pic)

    HI Guys, im just in the middle of designing a power supply for a board with Xilinx Spartan 3E and a couple CPLD's on it.. i have read a mountain of datasheets from Xilinx (ds312, ug313, ug786, xapp623 etc) and looked over a few schematics of boards with similar hardware.. allot use custom...
  16. 3BABY

    [SOLVED] Problem Reading Memory Addressed input port 8031/8051

    Thanks rohitkhanna (sorry about the late reply).. i will look into CJNE to SJMP , changed MOV DPTR,#102h to #101h and works great now.. i guess thats what i get for copy/paste my old test code and not checking it enough.. thanks for your help!!
  17. 3BABY

    [SOLVED] Problem Reading Memory Addressed input port 8031/8051

    ok so if i flick the power switch and then hold reset for a second or two and the take my finger off i get the above exibit. address FF01 and 0101 are explained like this: i want the input ports (all the ones i plan to address in the upper 255bits of address range so i chose FF01 as my first...
  18. 3BABY

    [SOLVED] Problem Reading Memory Addressed input port 8031/8051

    HI, yes sorry there is code below Start1: i just didnt put it above as it had no relevance to the problem, (basically just moves onto flash some lights on that same output port so i can see that the program has gotten past the first loop if the input was 0x01 - there is no further user input to...
  19. 3BABY

    [SOLVED] Problem Reading Memory Addressed input port 8031/8051

    Hi there, thanks for the reply, the CJNE will compare R4 to the value 0x01 and Jump to the below code "start1:" etc if R4 is equal to 0x01 if not it will jump to L1: (and test the input port again) is this correct (sorry a little new to 8051 assembly) or am i jumping to relative address of...
  20. 3BABY

    [SOLVED] Problem Reading Memory Addressed input port 8031/8051

    Hi Guys, so ive been putting together a 8031/8051 system on a breadboard with external PROM and going to be using external RAM, i can write to an External Memory address (by way of latch) and display the value on 8 LEDs no problem, the problem i have is i want to read an 8 bit value from a...

Part and Inventory Search

Top