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  1. Shahriar

    Why the Isolted 130V in Tv give us a shock!

    Hi In a TV, in its Isolated Sectin (Cold Chasis), when You touch 130V line, it gives you a Shock? How electricity close its circuit? This happen seriously with High voltage pins in deflection section too. Can anybody say why? ThanX Shahriar
  2. Shahriar

    The Triac doesn't turn off when I connect it to DC voltage!

    Hi I have a Triac, "BT136" when I connect the T1 and T2 Pins to AC voltage, I can turn it off and On with giving a DC voltage to Gate Pin, but when I try to Turn On and Off a DC load, the triac Doesn't turn Off? it remains On, till I disconnect the power! Shold I trigger the gate with a...
  3. Shahriar

    15A Lead Acide Battery Charger!

    Dear indulis I know that LM317 can not Handle 15A. I send that schematic to show how my circuit is going to charge that battery. INSTEAD OF that LM317, I want to use a PC ATX Power supply. Just to limit the current I want to pull Up the stand By pin PC Power supply. The Only thing I want to...
  4. Shahriar

    Home-made bench power supply voltage drift problem question.

    In TV reapiring, there are some problems that will beOkay a few minutes after the TV works. i.e. there is no Ruster,, {after few minutes, it appears.} it is alwasy beacuse of an Electrolit Cap. Bad Caps when get hot start working properly, but when they are cold, Some of their specifications...
  5. Shahriar

    PC PSU convertion...

    Yeah It is the best what Ante Said, because dealing with an ATX Power supply wihtout a Schematic is really Disgusting.... Shahriar
  6. Shahriar

    15A Lead Acide Battery Charger!

    Dear indulis I have attached  a file in my first message, (at the top of the Page). Its name is battery charger.PDF and has been downloaded 3 times. In which condition the output Current Will control th output voltage?  :o Like a LM317 Over-Current Protection, It is always, the output...
  7. Shahriar

    15A Lead Acide Battery Charger!

    Hi I attached that file to show that my device is going to work like the cicuit I have attached, the only difference is High current for my device. The circuit I have attached is a Current limited power supply. when The Battery wants to draw more that i.e. 1A the Output voltage drops to...
  8. Shahriar

    15A Lead Acide Battery Charger!

    Hi Someone has asked me to build a battery charger. The battry is a 24V / 150Ah from those kinds which is used in big vehicles. I think they Are called Lead acide battery!!! Am i Right? the battery is to be charged with a max Current of 15A! I decided to charge it with a circuit like the one I...
  9. Shahriar

    IR vs RF

    Dear Perseus Antenna theory is very complicated and any Shape antenna has its own specification and uses, but as I have seen in some SIMPLE remote controls, the Antenna shape does not have very Specific impression on the range. I am going to build it for some one, If I did it, I will tell you...
  10. Shahriar

    Help me modify FM Radio

    Dear Alun If it is not produced any more, Do you know any Substitute IC? ThanX Shahriar
  11. Shahriar

    IR vs RF

    Hi If you want to build a RF Remote control, i Think theis project will work fine. I have not build it yet but its design looks perfect. It belongs to 27MHz Toy Car. http://jap.hu/electronic/rf.html HTH - Shahriar
  12. Shahriar

    Help me modify FM Radio

    Hi There is an IC: "TDA7000". It is a complete radio IC. I couldn't find it in my area but I think you can. It is really easy to build a radio with using this IC. HTH - Shahriar
  13. Shahriar

    adjustable switching PSU 0-30v 0-5A

    Dear SupeR-NovA About 330ohm Res. For a Flyback PS, and Vi(min)=190V, Your calculation is right. About the output caps, although there are some calculation for them, but As I have Seen in many designs, if you put bigger Value, it would be better. But about the inductor, as you Yourself Know...
  14. Shahriar

    adjustable switching PSU 0-30v 0-5A

    Dear SupeR-NovA I was planning to build the same circuit. you asked: "how much power should i draw from the supply when there is no load connected? " You should draw current as much as the Controller doesn't turn off. because Controller Is supplying from an auxilary winding. the problem that...
  15. Shahriar

    amp. problem

    Dear jeevan772006 Once I had made a distributor Amplifier with NE5532 IC. I had the same problem, after a few hours I found that I had not Place one of  Jumpers which was related to -Vee Rail. So All of ICs didn't have a -Vee. As soon as I connected it everything went right!!! I was really...
  16. Shahriar

    What is "tunable ferrite"?

    Hi I want to build this Little transmitter. In descriptions,is written: " L1 = 9 turns, .15mm wire on 4.5mm diameter tunable ferrite coil former " 1- What is "tunable ferrite"?  L2=15 turns, .5mm wire, 5mm diameter L3=3.5 turns, .5mm wire, 5mm diameter 2- Can I replace L2 and L3 with...
  17. Shahriar

    Outout of a transformer!

    Dear Ante I also have the same Oponion. It seems impossible. ThanX Shahriar
  18. Shahriar

    Outout of a transformer!

    Dear Ante I think it is more clear now. If you didn't understand tell me to explain more. ThanX Shahriar
  19. Shahriar

    Outout of a transformer!

    Hi A university expert has said that: Imagine a transformer connected to a Ac Voltage (between Phase and Nuetral i.e. 100V). it has an output of i.e. 12V ac. If you connect this trasnformer to the same AC Voltage (100V) which this ac voltage is comming from Two Phase which have 100V then the...
  20. Shahriar

    high/ low level indicator

    Dear smoknjoe44 Maybe using an InfraRed receiver and transmitter will do the job. when there is enogh Bin, the receiver does not receive anything and the LED will turn On. HTH - Shahriar
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