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  • Turn 12$ transistor tester into 200$~600$ Smart tweezers LCR meter for SMD component (and even more)

    Hi,could you please post the link to the same transistor tester so i can buy one?

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  • doski90z followed antitaengbasuraman3 months ago
  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    A follow up... After getting everything soldered on a Pcb board the 2 function generators are working great but the oscilloscope is not working anymore!! All i get is a small noise even if the is nothing connected to the scope input..One more thing, I an using a single Trrs cable pluged to the phone were the ground GND of all circuits are connected to the trrs cable. should it be fine or should I use a separate cables for Fun.generators and the oscilloscope?

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    I finally made it :DRevewing my problems:After many many tries I made the entire circuit today. The problem I was facing was that I thought that the eagle schematics were representing the LM324 pins but that wasn't the case. Connecting each circuit represented in Eagle schematics provided to an op-amp In the LM324 solved the problem therefor I ended up using all 4 op amps of the LM324 for the 4 provided Eagle schematics circuits.Tansistors not found:I couldn't find the D44H11 so I tried BD226 NPN power transistor instead, simmilerly the D45H11 was replaced by a BD227 PNP power transistor and they work flawlessly. Using my Nexus tablet (2012) and the app called Function generator I was able to produces many wave forms with good frequency range, noise, amplitude, duty cycle etc..Also the ...see more »I finally made it :DRevewing my problems:After many many tries I made the entire circuit today. The problem I was facing was that I thought that the eagle schematics were representing the LM324 pins but that wasn't the case. Connecting each circuit represented in Eagle schematics provided to an op-amp In the LM324 solved the problem therefor I ended up using all 4 op amps of the LM324 for the 4 provided Eagle schematics circuits.Tansistors not found:I couldn't find the D44H11 so I tried BD226 NPN power transistor instead, simmilerly the D45H11 was replaced by a BD227 PNP power transistor and they work flawlessly. Using my Nexus tablet (2012) and the app called Function generator I was able to produces many wave forms with good frequency range, noise, amplitude, duty cycle etc..Also the oscilloscope works as it should.Thank you loboat fot the great project and I really wish that you include a note that the Eagle schematics are not related to the LM324 pins ;)

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    I WOULD SOOOO MUCH BE THANKFUL TO YOU if you could please make the schematics using the lm324 so that i can follow them and make this oscillo-fun.gen project. To be honest I am still learning and I have lettle knowlege about op-amps in general. I've been trying to build this circuit for 2 weeks and couldn't get it to work!!! It is my mistake i know and I need your help :)

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    I think there is something wrong with the first few nction generator. Pin7 of the opamp was not used as an output, instead you have used pin4 and the common which I can't understand why? Could you explain please :)

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    Can you explain to me how is the common, +ve and -ve connected to the lm324? Throgh which pins?I've tried to build it and i am getting no signal on my phone and I am getting +8 volts across ground (common) and left phone output (which goes into the smartphone) for left function generator and -8v through right phone outpout and common for right function generator. Is that normal? Is it going to harm my phone?

    please can you tell me how did you connect the common , positive and negative to the lm324 ??

    also , I am getting +8 volts across ground (common) and left phone input for left function generator and -8v through right and common for right function generator. Is that normal? Is it going to harm my phone?

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  • doski90z followed loboat and chipstein4 months ago
  • A Preamplifier for Smartphone Oscilloscopes

    Finally, I made it :Dsorry for bombarding you with my silly questions, this is my first Op amp circuit and I am so excited about it :)I finally built the full circuit dropping the zeners and using two normal inversed-polarity leds instead of the bipolar one. I figured out the I mixed up between -ve and Gnd and I had no good understanding about the need of common, -ve and +ve for those op amps. After fixing that (and frying a jrc4558) , My problem was not the connection itself but the jrc4558 op amp which worked for a while and got fried twice for an unknown reason while measuring a square wave produced by ic555 timer (why?) !!! I replaced it with lf353N and it works ok! When I put the jrc4558 it ges very hot and it would blow(why?)Notes and Questions:0- I used a 4.7uF capacitor because...see more »Finally, I made it :Dsorry for bombarding you with my silly questions, this is my first Op amp circuit and I am so excited about it :)I finally built the full circuit dropping the zeners and using two normal inversed-polarity leds instead of the bipolar one. I figured out the I mixed up between -ve and Gnd and I had no good understanding about the need of common, -ve and +ve for those op amps. After fixing that (and frying a jrc4558) , My problem was not the connection itself but the jrc4558 op amp which worked for a while and got fried twice for an unknown reason while measuring a square wave produced by ic555 timer (why?) !!! I replaced it with lf353N and it works ok! When I put the jrc4558 it ges very hot and it would blow(why?)Notes and Questions:0- I used a 4.7uF capacitor because I couldn't find a ceramic with this value. Is it possible to use a 470nf ceramic? What might be the effect on the circuit?1- I noticed that using the fl353N doesn't indicate the presice frequency generated by my phone, while the freq. meter on my multimeter reads 1000hz the Oscillscope pro app reads 1047 and fluctuating +-20Hz (is it really the op amp fault?)2-The wave shape changes when changing from Hi to Lo input at the same generated wave, why?3- I couldn't understand the callibration part, I measured the AC voltage of the 1000Hz sin wave from my ipad it was 0.245v , to callibrate the Oscilloscope app, where is the voltage indicated in the app? If it was the one reading delta m V then it is fluctuating so much that I can't know which is the correct value. What's missing??I would really appreciate it If you could discibe the process step by step so that my project is fully completed(thanks to you)

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  • A Preamplifier for Smartphone Oscilloscopes

    Ok, lets diagnose the problem.What i have done was1) I replaced the ceramic capacitor (4.7uf) with a polarized one where the posative terminal connects to the led (two parrallel leds inversed in polarities) and its negative terminal connects to the 1.5k resistor then the resistor to the negative of the battery (ground)2) I couldn't find a bipolar led so i used to normal leds in parallel each with inversed polariy meaning if enough voltage were passing one of them should be lit depending on the direction of current i guess The rest to the circuit is the same as the full circuit without the zener Diodes and the power indicator led.+ve of battery directly connects to pin8-ve of battery is connected to the ground os the circuit One Oscope testing probe is connected to the ground The other p...see more »Ok, lets diagnose the problem.What i have done was1) I replaced the ceramic capacitor (4.7uf) with a polarized one where the posative terminal connects to the led (two parrallel leds inversed in polarities) and its negative terminal connects to the 1.5k resistor then the resistor to the negative of the battery (ground)2) I couldn't find a bipolar led so i used to normal leds in parallel each with inversed polariy meaning if enough voltage were passing one of them should be lit depending on the direction of current i guess The rest to the circuit is the same as the full circuit without the zener Diodes and the power indicator led.+ve of battery directly connects to pin8-ve of battery is connected to the ground os the circuit One Oscope testing probe is connected to the ground The other probe connects to the pot thrugh a 0.1 uf capGround of the trrs connects to ground of circuit(negative of battery)Mic line connects to the negative side of the polarized 4.7uf cap (before the resistor 1.5k)What did i do wrong and Any suggestions to fix it is appreciated

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  • A Preamplifier for Smartphone Oscilloscopes

    Thank you chipstein, I found a 1m ohm pot today. I will start building the circuit soon and I'll update you with the results (hopefully the chip will work)

    so I built the minimal circuit using the 4558d and i used a 9v battery with the same schematics but the problem is that the chip gets hot and i dont know if thats normal or not, also i replaced the 9v battery with an 11v from an adjustable ATX power source which made the chip very very hot!!Whats going on??Also, I noticed that the battery gives more cleaner signal than the atx ( connected to mains)

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    I used two separatet different power supplies with an lm317 regulator to regulate 8 volts from each the then connected then in series getting common , +8 and -8 voltsI have built the circuit on a breadbord and Now the problem is when i built the circuit of the oscilloscope only, connecting the +8 to pin4 and -8 to pin 8 and common to ground them using the phone and the oscilloscope app the wave form has a great noise and distortion even without putting the probs on any thingSecond, after building the first signal gen. When i measure the voltage between the left input ( which should be connected to the phone) and the ground I get 8 volts!! If i plug the trrs into phone jack it will burn it also the out put of that left signal gen. Is 8 volts?! And when measuring the frequency coming ...see more »I used two separatet different power supplies with an lm317 regulator to regulate 8 volts from each the then connected then in series getting common , +8 and -8 voltsI have built the circuit on a breadbord and Now the problem is when i built the circuit of the oscilloscope only, connecting the +8 to pin4 and -8 to pin 8 and common to ground them using the phone and the oscilloscope app the wave form has a great noise and distortion even without putting the probs on any thingSecond, after building the first signal gen. When i measure the voltage between the left input ( which should be connected to the phone) and the ground I get 8 volts!! If i plug the trrs into phone jack it will burn it also the out put of that left signal gen. Is 8 volts?! And when measuring the frequency coming from it if is about 30 kHz and highly fluctuating , why is that happning

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  • OscilloPhone: Use your Smartphone as an Oscilloscope / Signal Generator

    Awesome instructable, I really like it, however,I can't find the -8 volt regulators in my city, is there anyways around to solve this problem?I do have a +8V regulator and lm317 and i have (+-)24Volt regulators as well. what is this best way to get -8V other than the specified one, or how can i use my adjustable power supply to regulate the -+8 volts?

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  • A Preamplifier for Smartphone Oscilloscopes

    Great instructable is should say :)In my country I couldn't fine this chip , but i found 4558d JRC dual op amp.1- Is it ok to use it? what are the possible effects.2- Also, I couldn't find a 1M pot but I do have a 500K pot and many resistors, can I use a 500K resistor in series with the 500K pot to create a 1M resistance in total?

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  • doski90z followed GreatScottLab4 months ago