If I can figure out the programming side of this device (total ISP noob), I want to add the zener threshold tester, but I plan to use a MC34063 if I go that route.
...And if everything goes really well I'd like to look into adding a INA106 differential amplifier with a laser trimmed gain of 10. I was planning to build the milliohm meter from the Scullcom Hobby Electronics YouTube channel, but I think the diff amp might be more useful when integrated into this project. I would probably need help understanding the programming aspects involved to make this happen, but I think this little mod could be interesting.
The last thing I've been looking into is why "discharged capacitors" are mentioned, but only 'before the device is powered on.' I assume this is due to the TVS IC's need for power. If that's the case, why not simply add a 2 pole normally closed relay to short all 3 test leads with a short on delay circuit powered from the collector of the PNP transistor? Seems like that would solve the problem of mega-burns, but I've not done my research in this area yet.
I'd recommend to add a second 5V LDO
Yes, I have tried with two similar ones with similar results. The last one read 6.36mH and 148 Ohm while in my multimeter it reads 0.63 Ohm. Don't know if it matters but both inductors are common mode chokes.
That's strange! I've checked a 2.7mH and 22mH common mode choke with the m-firmware an an older k-firmware. The measured values are reasonable.
Hi Pierre,
I had few minutes waiting for a meeting and took the opportunity to play a bit with your schematic, hope you don't mind It was just for fun.
Now the encoder should be fine and I moved few dots in the "proper" position.
Generally speaking I think the issue with the dots is related on how Eagle works.
You should avoid start a junction or a 90degree corner on a component pin.
If you do that, Eagle attach the junction to the component pin and if you move the component you drag the dot junction with it.
I don't like to draw lines or components underneath other components and I moved some wires to avoid it.
I prefer to use the GND simbol and power pin simbol instead of drawing all the wires for the power all around the schematic, but I didn't change that.
Please let me know if was this was helpful.
Enjoy your drawing
Mauro
PS: Why use Eagle? I got used to it and I'm struggling to move to Kikad. For small board it is free, so sometimes for me is just faster to do it in Eagle.
Tried Kicad , I'll stick to altium.
Article AVR Transistortester on mikrocontroller.net
The SRV05-4 is "passive" and doesn't need any supply voltage.
... The Tester may be damaged before you have switched it on. There is only a little protection at the ATmega ports.
...there's aleady a discharge/protection relay add-on.
Have you seen Karl-Heinz' excellent documentation yet?
I'd recommend to add a second 5V LDOI preferred a 5V micro switching module.
It can deliver much more current and can be used for:
- servo test (with the m-firmware)
- bluetooth module (enabling the serial output on the k-firmware)
- Zener test (as the input for the boost converter)
I added also a switch to save battery power if this secondary voltage is not in use.
I would add the 3 pin standard header for the servo test and a connector for the serial output (PC3 on the k-firmware).
Mauro
The SRV05-4 is "passive" and doesn't need any supply voltage.When a DUT capacitor with a charge is connected, and the test points are connected to a SRV05-4 what exactly causes the failure? Is it simply the potential across the test pins without the completed Vcc to GND loop? I'm mostly confused because of how KH words the warning on the pdf:Quote... The Tester may be damaged before you have switched it on. There is only a little protection at the ATmega ports.Does the same damage occur regardless of whether the device is on or off?
...there's aleady a discharge/protection relay add-on.I read somewhere recently (sorry haven't found the ref), there is a problem, as the circuit is documented. The current draw of the transistor/relay combined with the gain of any BJT transistor pulled too much current. They had mentioned the problem was due to the relay connection at the Vref point. Maybe that person was wrong, I don't know, but the maths looked right to my amateur understanding.
Why would you run 2 linear regulators? Are you guys implying the use of the DC converter to power the transistor tester itself, or am I misunderstanding something else?
Hi allI
have one of those, and when I power it from a adjsutable power supply, it says "Bat. 10V OK". But i'm supllying it 9V, at least that's what's my multimeter (uni-t ut61E) says...
Is it something that could be a problem or it doesn't matter?
Thanks!
Sounds very much like a low accuracy resistor in the voltage divider. Does this also happen when you connect a battery?No problem, it is ok and bear in mind that the values are for indication inly (ie could be way off as you have found)
[...]
I wouldn't say that. If it's way off, the automatic shutoff will not work right, and when running on rechargeable battery power it could mean discharging the battery beyond its limit or using the unit with voltages below the expected 5V on VCC.
Is there some recommandations about available kits one can buy? I got one that broke and a second one that reads voltage 1V under the real value (and all surface mount).
It would be nice if someone has a recommendation for a kit up-to-date and reliable, prefereably through hole.
Also, is there a way to browse the 140 pages on one page? I am suscribed to another forum where there is this option.Then with ctrl+F it is easy to navigate through and find the information.
Click the Print button at the end of the last post on a page. That will not print the page, but open a printer-friendly version, which also contains all the posts in one stream.
Is there some recommandations about available kits one can buy? I got one that broke and a second one that reads voltage 1V under the real value (and all surface mount).
It would be nice if someone has a recommendation for a kit up-to-date and reliable, prefereably through hole.
With so many variations out there, it's kind of hard to make recommendations having not owned them all. Not long ago, it was pretty easy to recommend the red AY-AT version since it had all the bells and whistles and worked fine. Now, it seems there are several variants of it as well.
I have bought an AYAT on ebay assembled it.. replaced the crystal with 16Mhz also compiled the latest 1.29m in AtmelStudio7 for 16mhz.. everything seems to work fine.. except I cant make the selfAdjustment to work correctly.. I read from madires post that I should measure a 220nF-1uF film capacitor 3 times then do the adjustment test... but everytime I do that an error comes out at the very end instead of done... doing the adjustment without measuring a capacitor completes without error... also after the adjustment shorting any probes shows 0.01-0.05 ohms instead of 0 homs.. Is this expected or not.. thanks..
I just bought this direct from taobao. I think it is most suitable for me at this time. Last I checked, it was not available on ebay or banggood. They have an adapter that plugs into the 4mm. The adapter has a ZIF socket and surface mount pad.
Edit:
This unit could run
https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_st7565_kit
Is there a "m" version readily available for this kit? Thanks.
I have bought an AYAT on ebay assembled it.. replaced the crystal with 16Mhz also compiled the latest 1.29m in AtmelStudio7 for 16mhz.. everything seems to work fine.. except I cant make the selfAdjustment to work correctly.. I read from madires post that I should measure a 220nF-1uF film capacitor 3 times then do the adjustment test... but everytime I do that an error comes out at the very end instead of done... doing the adjustment without measuring a capacitor completes without error... also after the adjustment shorting any probes shows 0.01-0.05 ohms instead of 0 homs.. Is this expected or not.. thanks..
Before the tester reports an error or success the adjustment values are displayed. Please post those values (with the cap measurements done before the self adjustment).
And if you create the short circuit after the cap measurement before running the self adjustment? The short circuit will trigger the main menu. Simply keep the probes shorted and run the self adjustment