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Everything posted by BOHDA

  1. New interesting project at http://www.mindbend.ro/eoscope/eoscope_en.htm A must to see one and a place for improvings!
  2. I try to download Rectifier Book from this page,but nothing comes!So I look for it with Google-here is the result www.ieeta.pt/~alex/docs/ApplicationNotes/ Rectifier%20Applications%20Handbook.pdf .By same ONSEMI you can get SWITCHMODE Power Supply Reference Manual at www.onsemi.com/pub/Collateral/SMPSRM-D.PDF
  3. Hello Ante I see last observations about zenner diodes and I have to put a question-In this case can not be used TL431? About the PCB-Is anyone who made a new PCB for PS?The old one is a little too big and can not support curents above 3A.
  4. Hello I read all the question about PS. I have to point some things about this,as follows. To obtain more DC current you must use an power trafo,that means more than 150 w[better 200 or 250w]. The best way to reduce waste power at low voltage and great currents is to split the secondary on two,that means 12V and 24V in AC.In this case you must use a switch. Instead of a single 2N3055 it is possible to use 2-4 pieces mounted in parallel.Each 2N3055 must have an resistor 0.1 to 0.22 ohm at 5 to 10 watt. For driving more transistor in the case above I think is better to test a BD139 instead of 2N2219[Whis an beta greater than 100]. I have attached schematic of a very good PS which was very well tested,as a suggestion to try modifications. -
  5. Sorry about my previous reply.I make an txt,instead of simple message.So I rewrite the previous with some adnotations. I have buid the LC Meter.It works fine.I use the same hex that Kiriakos has mentioned.Also I use an 2x16 display because I did not have an 1x16[is HD44780 type]. All characters are displayed,even they are now separated on two lines. The PCB is good,only in schematics are some minor mistakes. I think the problem is,if the MCU was right written,in some bad conection between MCU and LCD display.You have to respect the PCB . Also you can contact Fenard,is open to consulting. The values for oscillator are 400 pF and 49 uH. I also do not use RS485 on PCB[ no conection between MCU and RS485].Fenard wrote to me and advise for this. The working of LM311 oscillator is ease to detect by an oscilloscope,or an rf voltmeter[even on DC scale of DVM you can see at the output of LM the variyng voltage]
  6. I take a look to your question.The L1 and L2 are made on an 5mm spiral drill,with an 0.5 mm wire,and have each 8 turns.There is nothing strange here,just usual indications for coils.
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