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Everything posted by shaiqbashir

  1. Hi Guys! How are you? well! im trying to make the following project: http://www.electronics-lab.com/projects/pc/023/index.html Now the problem is that following parts are not available in my areas: 400MHz resonator 200MHz resonator remember that the author of this circuit has advised me that you can use a resonator for producing this frequency. Now the problem is this that in my market, such large resonators are not available. Please tell me some alternative, so that i can make this project. Secondly, do anyone think that this project has any faults in it? If yes then please point out them to me. Thanks in advance Good Bye!
  2. Well! My friends donot think that im joking here!!!! I know all that which u told me. Well! i have seen that theoritically its working but practically not perhaps. I made the same circuit which i have drawn in my 1st post above. When i checked it thru the Multimeter, the result was awful!!! it was giving me very less than 9V drop across both 20ohm resistor and 100ohm resistor. I have changed the multimeter, but the otherone was also giving me the same results, which i got from the 1st. Tell me why im not getting 9V across each resistor heere. Is Parallel combination law is not violating here. Secondly if i suppose that ok Parallell combination law is correct, tell me is this not violating the Law of Conservation of Energy. If i follow the parallel combination, then it would simply mean that i can connect the bulbs of whole town across one source( Lets say of 100V) and each bulb would be having 100 V across it. Isnt that terrible? I dont think that this law is practically true, plz clearify this point. Thanks
  3. Hi Guys! well! today i have a very simple question to u. The circuit which i have drawn below is a simple parallel combination circuit. Can u Tell me the voltage across each resistor separately.i.e. What is the voltage across 20ohm resistor? What is the voltage across 100ohm resistor? Im not joking here, i need an answer, thanks in advance 20ohm ____/\/\/\/\/\____ | | | | ____/\/\/\/\/\/\___ 100ohm | | | | | | | |______| |_____| | | | 9V well! i know that its a terrible drawing, sorry but i couldnt attached my circuit here. Hope u can understand that.
  4. Hi Audio Guru! my dear friend! i know this thing already, but when i went to an electronics shop, he gave me a trimmer of 100uf. so that is why im using it here. dont u think it is possible? sorry but i really didnt understand what u r trying to say here. My circuit gives an amplification at even 1mV. so why are u saying that it might even have a loss. Plz further clearify it. when im getting a gain at such a high value so what can i do abt it. my question is WHY i cannot use, what is the rule of not using it.and if im deliberately using it, what is the harm in it? Plz clearify this as well, secondly give any MOSFET model recommendation which u think can be easily available in the market. Thanks in advance again
  5. HI Guys! well! i have a simple question to u. I know this thing that a microphone provides u with some AC voltage in an audio amplifier. But what is that voltage in an audio amplifier, that goes into the speaker in order to drive it. Is it AC or DC? Thanks in advance!
  6. Hi Guys! well! i have made the amplifier whose picture i have attached in this post. It is just a voltage amplifier, no sound, no speakers. All the voltages will be provided thru the COnsoles available in our labs. I want to ask u somethings here: First of all! have a close look at this amplifier, do u think that it can be easily implemented, i mean! should i now make it on a breadboard or veroboard. which one will be suitable. Secondly, this amplifier, has the speciality in my eyes, that if u just adjust the value of the 100uF trimmer (C4) present, u can vary ur input signal from 30mV to 0.3V, which will give u a contant output of nearly 2.7V. Is it good to see or not. Thirdly, i want to know the main functions of the feedbacks that i have provided in this circuit. To be more simple, i want to know what is the function of R3, R5, C4. and how it happens that changing the value of trimmer can give u a constant voltage at the output. Remember the resistor of 10K is my load. and there is nothing such like sound. If u think that this circuit has some drawbacks, plz point them out clearly so that i can improve it further. Thanks in advance.
  7. Hi Guys! im facing a terrible problem here. I have designed a circuit that works very well according to my software simulation. Remember im using MULTISIM 2001 for the circuit simulation. But when i tried to make the same ciruit on my breadboard, it just didnt give me the same results, infact some totally unexpected results were obtained and my objective was not obtained. Can plz u tell me what may be the problem?
  8. Hi Guys! Well! i have a circuit in which the following two components are used. This circuit is of a transmitter: 1)Varicap Diode 2)Ceramic Filter (crystal) one problem is this that the above two components, i just donot know about them. Can u plz suggest me any alternative, that i can put in my circuit. Alternative should be a simpler one. Lets say, i read somewhere that the Varicap diode can be replaced by an ordinary diode like LED. is it true. Here's my circuit: Thanks in advance
  9. Hi Guys! i have posted my circuit below which u can see. I have two questions here: 1) Which MOSFET will be the most suitable one for this amplifier? 2)What will be the magnitude of the input signal generated by the microphone? Let me clearify my questions to u! well! the input signal source given in my circuit is actually a microphone. I want to know that what is the magnitude of the greatest signal that can be generated by the microphone? how can i find that? how much my circuit can bear? my circuit gives the best result when it is not more than 0.3V. so how can i limit the microphone signal not to exceed the limit of 0.3V? Please help me as soon as possible. and tell me some MOSFET which can replace this IRFE130 because it is not available here. Secondly! if i want to connect IRF840 or IRF510 in place of it, what changes i have to make? Thanks in advance!
  10. Hi Guys! how are u all? Well! i want to ask u people a simple question? Is it possible to make an amplifier with the help of MOSFETS only, remember, no BJTs, No Power FETs, only simple MOSFETS , capacitors, resistors, diodes ZENERS are allowed. Plz help me because i have to make a project and plz again remember before answering: ONLY MOSFETS should be used as a transistors. Thanks in advance
  11. Thanks a lot Audioguru! your help has really improved my ideas and designs. But one thing that i always want to ask to you is How to add an AC negative feedback in an amplifier circuit. Can u give me an example please. After adding it, according to u, it would give me sufficienlty low output impedance, so my amplifier would not be affected by any load, then would it be able to drive an 8-ohm speaker. Thanks a lot in advance!
  12. Hi Guys! thanks a lot for ur help audioguru. But still i want to ask u one thing. I have read that the drain followers are used when u need a very little voltage gain and i need a high voltage gain that is why im using source followers, then why are u compelling me to use drain followers. secondly, how is it possible to operate the same circuit with an input signal from 0.1V to 0.5 V. how should i make my output impedance so small that the same voltage gain is produced either with the 10K load or 8ohm load. Please provide me details if u like. im in extreme need of help, Thanks a lot in advance. And how can i make that i
  13. Hi Guys! thanks a lot audioguru for ur help. I considered your suggestions of having a negaitve feedback in my amplifier and now i have designed one thing which i have attached here. But i want to ask a few things: 1) this amplifier gives best results with the voltages in mVs like 1mV 2mV etc. but it gives terrible results with the voltages like 0.1V-0.5V. which we donot want at all. we want it to work well with the inputs of 0.1V to 0.5V. 2)is it a true thing that the output voltage in this amplifier doesnot depend upon the load resistor. i mean that in my amplifier(below) i have connected a 10K resistor as a load one, but i have seen that when i change my load to some other resisitance like 1K or something else, the result also changes and clippings and distortions occur. Can u tell me any way to operate any resistance as a load in this amplifier. Please help me as soon as possible. Thanks in advance
  14. Thanks a lot audioguru! you have proved to be a real helper for me. But there is another humble request to you. That will u plz review the circuit which u have suggested. Only basics i want, Plz Plz. I shall be very thankfull to u for this act of kindness. Thanks in advance
  15. Hi guys! the circuit i have made, i have attached it. Now what i desire actually is to use an 8-ohm speaker. tell me is this the amplifier which can be used to drive an 8ohm speaker. if not than what should i do. remember that the 8-ohm resistor is actually my load. Plz help me and remember use only FETs in ur suggestions. Thanks in advance!
  16. Hi Guys! well! i have designed a mosfet amplifier. This amplifier uses only MOSFET in its operation along with an input signal and capactors and resistors and VDD. I want to ask u one thing. The amplifier which i have designed takes 0.1V of AC signal as an input and provides a gain of 3.3V/V. it is best for a load of 10K resistor. If i want to connect an 8-Ohm speaker as a load in place of 10K resistor, what modifications do i have to make. Plz help me. Thanks a lot in advance
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