Continue to Site

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.

Register Log in

Recent content by cupoftea

  1. C

    Current mode with SG3524

    Thanks, yes, i mean would just reference the CT ground to a 0.5Volt gotten from a divider. Thing is, the ramp is expected to be 0.5V to 3,8V....so thats going to put more magnetising current into the CST, and mean a larger CST. I suppose we can limit the ramp to 1V, (say), and then clamp the...
  2. C

    Current mode with SG3524

    Thanks, current mode, as opposed to "voltage mode" Current mode , is where typically, an output voltage is regulated by an error amplifier, which drives the PWM comparator input...the other input of this comparator, is a repeatedly ramping current, from the power stage inductance...as opposed...
  3. C

    Current mode with SG3524

    For current mode operation with SG3524...or indeed, the pin4pin UC3524 The comparator is expecting a ramp from 0.5v to 3.8V..... So i guess a biased up current sense transformer output.... Do you have better ways? SG3524...
  4. C

    Measuring interwinding capacitance

    Thanks, i guess i should have pressed the "Z, theta" button on the LCR.?...and if the angle read -90degs or near that, then whatever frequency i was at was OK......since it must have been a reading dominated by capacitance if theta was right near -90degs.
  5. C

    AS331 comparator has ESD diodes from each pin to Vcc and Gnd?

    Hi, AS331 doesnt show ESD diodes from pins to GND and VCC pins....but are they there? (they surely must be?) Esp considering the OUTPUT pin? AS331 datasheet https://www.diodes.com/assets/Datasheets/AS331.pdf
  6. C

    Measuring interwinding capacitance

    OK thanks, i measured at 100kHz because that is the switching frequency. (well, switching frequency is 150kHz but 100Khz is generally "near" the various switching frequencies that get used, and its nice to keep it the same each time)
  7. C

    Measuring interwinding capacitance

    Hi, Sorry i was trying to redo it, but was too late...please find it here......not had enough coffee's yet i think in my case... This video says to short pri and sec coils then measure their interwinding capacitance However, this video says to just leave pri and sec open, and connect to them...
  8. C

    Measuring interwinding capacitance

    Hi, This video says to short pri and sec coild then measure leakage inductance
  9. C

    Opto isolated feedback: Opto pulls down COMP

    Thanks, this is interesting.....suppose the opto had been set up as Crutschow kindly says....ie in CC....with emitter pouring current into a grounded resistor...and this then put into the SG3524 with its error amp set up as an inverting amp....would this be preferable to simply pulling the COMP...
  10. C

    Type 2 compensator with TL431/Opto

    Hi, On page 30 of this... https://powersimtof.com/Downloads/PPTs/The%20TL431%20in%20Switching%20Power%20Supplies.pdf ...we see a Type 2 compensator done with TL431/opto. However, the most commonly seen form of this is seen with C1 being exchanged for an RC series circuit, call it R2_C1. Then...
  11. C

    Simple inrush limiter has problems

    Thanks vert much for your reply.., it was the fear that even though SOA is the "one off survive" thing...maybe after a year of it it goes kapputt. 1600W just seems crazy for a 5x6mm SMD FET, even if only for 100us or so.
  12. C

    Opto isolated feedback: Opto pulls down COMP

    Thanks, in the schem that we have been sent, the inverting pin of the error amp is hard conncted to ground.....the non inverting input is connected to a 2.5V...divider off vref.
  13. C

    Open/Short calibration with a LCR meter test probe?

    Thanks, if we use the HZ186 to test a transformer, with connections to primary and secondary, then do we need to do open/short calibration on it in the same manner is is shown (in post #1) for the LCX-Z5? (ie outer connections open, inner connections shorted, for the "open" calibration)
  14. C

    Open/Short calibration with a LCR meter test probe?

    Hi, On page 62 (R.H.S) of this doc... https://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_manuals/gb_1/h/hm8118_1/HM8118_UserManual_de_en_06.pdf ..They show how to do an open/short calibration on the HZ186 LCR meter "transformer" probe fixture. The LCX-Z5 is the same as the...
  15. C

    PushPull SMPS with no primary snubber

    Hi, Customer has sent us a Voltage mode , isolated Pushpull SMPS, 24vin, 24vout and 200W, (np/ns = 5:9) each stage 75kHz. The Pri FETs are IRF540, but there is no primary snubber whatsoever. So far they only sent us the schem, they say its been working for years, but want us to have a look after...
See more

Part and Inventory Search

Back
Top