Here's the direct link to order the IsaiGUY op amp boards from PCBWay. www.pcbway.com/project/shareproject/Op_amp_Test_Board_77211aaf.html If you are setting up new account use the link in the video description (this video) to get $5 off your first order
For an opamp tester I would like to be able to hear audio. For example I reversed and re-designed a special vertical multi-pin ceramic pre-amp module containing a LM324, LM358 and a bunch of resistors and tantalum capacitors which came off an arcade PCB. The numbers on the parts were erased and it turned out that the LM358 didn't work correctly and the audio was distorted. I swapped the LM358 for a JRC4560 and that fixed the audio issue.... same pinout but obviously functioning differently when used in an audio circuit. So some kind of common single or dual power amp chip (like a LM386) and a small real 1" or 2" speaker (like out of an old PC, not piezo) would be useful. Also it needs to support 14 pin quad op amps too such as TL074, TL084, LM324 etc etc
If you're working with audio(or other low-frequency signals) only, you can use the sound card in your PC or laptop to observe what is happening with the signals. There are even applications available that can turn your sound card into an oscilloscope.
Laptop etc also works well for a signal generator too 😁 Making mushrooms and shapes appear on my old analog scope bought more joy than it probably should have.
@@LearnElectronicsRepair If you are designing and making test equipment don't make it rely on other stuff (like a PC). A stand-alone tester is easier to use since it requires nothing else and if the tester becomes faulty you are not having to troubleshoot half a dozen other pieces of crap hanging off it.
@30:59 It should be noted when talking about bandwidth, that as the frequency goes up, the maximum gain goes down. This will be shown in the data sheet as the open loop gain graph. From this we can calculate the maximum gain at any given frequency. With suitable feedback, we can create a circuit with a wide bandwidth at low gain, or a lower bandwidth at higher gain. Unity gain is the frequency at which the op amp has a gain of 1.
I've learned more from people like Richard and Sorin from Electronics Repair School than I ever have at any school. That is absolutely crazy 🤣 Merry Christmas everybody. Hopefully 2024 treats us better.
Thank you Richard for sharing your expertise again .. OpAmp's are still a bit of a mystery to me but your past two lessons have really put me in the right direction . Looking forward to Det and yourself's further explanations and experimentations .. Merry Cristmas and a Happy New Year on the Spanish Isle
If you are going to use a microcontroller as the brains you could use a simple Arduino Pro Mini 328 at $2 each. Just design your board so the footprint of the Arduino pins are at the correct location on the PCB and the Pro Mini can be mounted onto the board directly into a socket so that the GPIO pins connect to the pcb. Also include the serialUSB interface parts so it can be re-programmed easily as the Pro Mini requires an external serial interface or use one of the cheaper Arduinos that includes a serialusb interface.
While it is very common for split supplies to be equal it is certainly not essential and not always the case. In some circuits it is perfectly acceptable to have something like +12 V and -5 V supply rails. In audio circuits it is mostly likely that the supplies will be symmetric around ground. In industrial circuits asymmetric supplies are more common. Asymmetric supplies are pretty common in things like adjustable linear bench power supplies. There you might find something like +30 and -2 volt supply rails. Meters can cause all sorts of problems in analog circuits. The leads pick up large amounts of noise and a substantial amount of capacitance can be introduced. Often this doesn't matter if all you are looking at is the meter but it can make a mess of the circuit behavior if you are looking at something with an oscilloscope at the same time, or listening to an audio output. Sometimes the change in the circuit behavior is reflected even in the meter readings. One way to reduce this problem is to use resistors in series with the meter leads, as close as possible to the probe tip. A resistor of 10k can make a big improvement and introduce only a very small error (~0.1%) with a typical DMM with 10M input resistance. Of course in high impedance circuits the 10M input resistance of the meter can itself cause major error in the circuit. It rather boggles my mind that anyone would have use for a slew rate tester. I guess it is symptomatic of the fact that there are so many counterfeit parts around.
I was kind of hoping this one would end up with a micro-processor multi purpose solution. There are several ways to go about this. One would be a self contained unit, but alternatively, you could make one as a 'hat' (extension board) for an existing platform (IE One of the more powerful Arduinos / raspberry pies or even a board that you just plug an ESP32 development board into - some of these come with a small colour display already on the board. You demonstrated that all op-amps will have an upper frequency where the slew rate becomes unusable - therefore you need to be able to change frequency. It may be nice to have some pots for this alongside some pots that can be used to change the feedback ratio. If a micro-controller with quite a lot of i/o channels is used, the board could have four different sockets each configured for the four different common configurations. Do single channel op-amps follow the same pinout as one side of the dual channel op-amps? if so, then the same socket could be used to both types. Another consideration, do you configure it around 4 channel op-amps and put a dual channel socket alongside it connected in parallel? Just a few thought from the top of my head without getting too caried away (like having a second function like a basic signal generator).
Most psu schematics don't exist and are not public. You could reverse it and make your own schematic as you have it right there in front of you on the board. Simple reverse it and put it on paper or use cad software. If you can't do that then you also can't fix a complex modern high amperage multi-voltage SMPS PC power supply so just toss it and buy a new one like most people do. Having said that, asking for a pc power supply schematic without actually giving any useful info about the make/model won't get you anything.
hi if you have a 16 channel reel to reel if one of the rails goe's bad we have to pull all the cards out to check the power rails coming out of the power unit i have some tasacm 38 's i find it's the part that doe's the 15v rails i did check all the cards all 60 cards not one op amp was bad op amps do over heat i had this because of the power unit
I wanted ImsaiGuys board. However I've never designed a PCB and all the drop-down boxes on the site confuse the living circuit out of me. I'd like to order it knowing I have all the settings right.
Here's the direct link to order the IsaiGUY op amp boards from PCBWay. www.pcbway.com/project/shareproject/Op_amp_Test_Board_77211aaf.html If you are setting up new account use the link in the video description (this video) to get $5 off your first order
Here's the direct link to order the IsaiGUY op amp boards from PCBWay.
www.pcbway.com/project/shareproject/Op_amp_Test_Board_77211aaf.html
If you are setting up new account use the link in the video description (this video) to get $5 off your first order
imsaiguy ;)
For an opamp tester I would like to be able to hear audio. For example I reversed and re-designed a special vertical multi-pin ceramic pre-amp module containing a LM324, LM358 and a bunch of resistors and tantalum capacitors which came off an arcade PCB. The numbers on the parts were erased and it turned out that the LM358 didn't work correctly and the audio was distorted. I swapped the LM358 for a JRC4560 and that fixed the audio issue.... same pinout but obviously functioning differently when used in an audio circuit. So some kind of common single or dual power amp chip (like a LM386) and a small real 1" or 2" speaker (like out of an old PC, not piezo) would be useful. Also it needs to support 14 pin quad op amps too such as TL074, TL084, LM324 etc etc
Thank you for the videos! This content is gold.
Incredible, you gained 2000 subscribers in twenty-four hours!
If you're working with audio(or other low-frequency signals) only, you can use the sound card in your PC or laptop to observe what is happening with the signals. There are even applications available that can turn your sound card into an oscilloscope.
Yes I agree... and that gives me an idea for another video 🙂Cheers
Laptop etc also works well for a signal generator too 😁 Making mushrooms and shapes appear on my old analog scope bought more joy than it probably should have.
@@LearnElectronicsRepair If you are designing and making test equipment don't make it rely on other stuff (like a PC). A stand-alone tester is easier to use since it requires nothing else and if the tester becomes faulty you are not having to troubleshoot half a dozen other pieces of crap hanging off it.
Great ! Merry Christmas....cheers!
Hi friend thanks for the informative video
@30:59 It should be noted when talking about bandwidth, that as the frequency goes up, the maximum gain goes down. This will be shown in the data sheet as the open loop gain graph. From this we can calculate the maximum gain at any given frequency. With suitable feedback, we can create a circuit with a wide bandwidth at low gain, or a lower bandwidth at higher gain. Unity gain is the frequency at which the op amp has a gain of 1.
I've learned more from people like Richard and Sorin from Electronics Repair School than I ever have at any school. That is absolutely crazy 🤣
Merry Christmas everybody. Hopefully 2024 treats us better.
Thank you Richard for sharing your expertise again .. OpAmp's are still a bit of a mystery to me but your past two lessons have really put me in the right direction . Looking forward to Det and yourself's further explanations and experimentations .. Merry Cristmas and a Happy New Year on the Spanish Isle
If you are going to use a microcontroller as the brains you could use a simple Arduino Pro Mini 328 at $2 each. Just design your board so the footprint of the Arduino pins are at the correct location on the PCB and the Pro Mini can be mounted onto the board directly into a socket so that the GPIO pins connect to the pcb. Also include the serialUSB interface parts so it can be re-programmed easily as the Pro Mini requires an external serial interface or use one of the cheaper Arduinos that includes a serialusb interface.
While it is very common for split supplies to be equal it is certainly not essential and not always the case. In some circuits it is perfectly acceptable to have something like +12 V and -5 V supply rails. In audio circuits it is mostly likely that the supplies will be symmetric around ground. In industrial circuits asymmetric supplies are more common. Asymmetric supplies are pretty common in things like adjustable linear bench power supplies. There you might find something like +30 and -2 volt supply rails.
Meters can cause all sorts of problems in analog circuits. The leads pick up large amounts of noise and a substantial amount of capacitance can be introduced. Often this doesn't matter if all you are looking at is the meter but it can make a mess of the circuit behavior if you are looking at something with an oscilloscope at the same time, or listening to an audio output. Sometimes the change in the circuit behavior is reflected even in the meter readings. One way to reduce this problem is to use resistors in series with the meter leads, as close as possible to the probe tip. A resistor of 10k can make a big improvement and introduce only a very small error (~0.1%) with a typical DMM with 10M input resistance. Of course in high impedance circuits the 10M input resistance of the meter can itself cause major error in the circuit.
It rather boggles my mind that anyone would have use for a slew rate tester. I guess it is symptomatic of the fact that there are so many counterfeit parts around.
Happy New Year 🥳
I was kind of hoping this one would end up with a micro-processor multi purpose solution. There are several ways to go about this. One would be a self contained unit, but alternatively, you could make one as a 'hat' (extension board) for an existing platform (IE One of the more powerful Arduinos / raspberry pies or even a board that you just plug an ESP32 development board into - some of these come with a small colour display already on the board. You demonstrated that all op-amps will have an upper frequency where the slew rate becomes unusable - therefore you need to be able to change frequency. It may be nice to have some pots for this alongside some pots that can be used to change the feedback ratio. If a micro-controller with quite a lot of i/o channels is used, the board could have four different sockets each configured for the four different common configurations. Do single channel op-amps follow the same pinout as one side of the dual channel op-amps? if so, then the same socket could be used to both types. Another consideration, do you configure it around 4 channel op-amps and put a dual channel socket alongside it connected in parallel? Just a few thought from the top of my head without getting too caried away (like having a second function like a basic signal generator).
Nicely explain ...thank you sir
Merry Christmas. Not to be off topic but where can I find a couple of schematics for PC power supplies that I am trying to repair?
Most psu schematics don't exist and are not public. You could reverse it and make your own schematic as you have it right there in front of you on the board. Simple reverse it and put it on paper or use cad software. If you can't do that then you also can't fix a complex modern high amperage multi-voltage SMPS PC power supply so just toss it and buy a new one like most people do. Having said that, asking for a pc power supply schematic without actually giving any useful info about the make/model won't get you anything.
See Richard's video on repairing an ATX power supply.
hi if you have a 16 channel reel to reel if one of the rails goe's bad we have to pull all the cards out to check the power rails coming out of the power unit
i have some tasacm 38 's i find it's the part that doe's the 15v rails i did check all the cards all 60 cards not one op amp was bad
op amps do over heat i had this because of the power unit
opamps are my favourite components
i dunno why
Thanks , great lesson. Blessed Christmas and a blessed 2024 for you and the family in Jesus Christ name amen.
Merry Christmas @all.
I wanted ImsaiGuys board. However I've never designed a PCB and all the drop-down boxes on the site confuse the living circuit out of me. I'd like to order it knowing I have all the settings right.
Here's the direct link to order the IsaiGUY op amp boards from PCBWay.
www.pcbway.com/project/shareproject/Op_amp_Test_Board_77211aaf.html
If you are setting up new account use the link in the video description (this video) to get $5 off your first order
why not combine the 2 and also for quad opamps ... then you got all in one tester ??!!!