Rich - what a great project! Look fwd to building one and thanks for making it out of discrete components. It would have been SO handy last night to test the LM358 and TL062s that I blew up on my DM6013L "el cheapo" 10 euro capacitance tester (could have been much worse... if it was an more sensitive piece of gear (like me) or the ESR meter or scope, lol...so much for the meter being fused...) . Yep - despite your best warnings about always discharging caps properly before testing, forgot one... - well... late at night sometimes we are not always fully awake. Lesson learned... Anyhow, replaced the op amps and a few transistors and it seems on the road to recovery (the oscillator 8/80/800 Hz is working now thru the ranges) but the output measurement on the LCD is still displaying wrong static values that only change value when the range setting is changed. So I suspect (lots) more cooked components. Of course... cant find a schematic for the DM6013L ... I will order a new capacitance meter but it is a good learning project to see what exactly went up in flames and to see if I can repair it, lol.
Looks like a great idea, for a custom 3D printed type socket. Where you would slide the chip in as you say, with pins taken from header, or mounted on top of two 4 pin headers. I looked up the data sheet for a TL082, and pin headers, and the dimensions work. Paul, USA!!!
no you don't want custom anything. plus it's a 50c chip. you don't spend a year and thousands on equipment to build something that can test a 50c chip lol
@@g4z-kb7ctEven if Richard doesn't have a 3D printer himself, Detlef or another friend might have one. I don't think it's a bad idea. Just a template frame that accepts a SOIC/ SOP chip would be printable under an hour. If you go a little bit fancier you can even build in plastic leaf springs to keep the chip locked during testing.
Hi Rick you can use UV curable board mask and then with several layers you can do it as thick as you want. This way you can also skip the flattening part :)
A simple test for transistors, you could add two multivibrator circuits, one for PNP one for NPN, with one fixed transistor in each version and then test a transistor plugged into the second half. Label the NPN and PNP C B E sockets. Have two LEDs that will flash for each pass result, either NPN or PNP.
If the smd chips are all the same size give or take 0.5mm you can add some smd 0-ohm resistors to the pcb soldered in place top and bottom of chip to give a guide for placing the part with at least 0.25mm clearance to allow for variations in the plastic package. They would be mounted while having an opamp chip in place to get the clearance correct. You can't really put guides next to the chip pins unless it's something plastic otherwise it can cause the chip pins to short together and mess up the testing. I think top and bottom guides is enough. Also be sure to make the smd pads long enough to cover 150mil and 200mil packages. I regularly see LM358 in 150mil and 200 mil so to cover that make the length of the legs fit the 200mil and then extend them towards the middle so there's about a 2mm gap and that will cover 150mil chips.
Another option to add is a power option. Use a common usb connector for 5v (ideally USB-B... i.e. any common printer cable etc powered from any PC or use a usb power bank or ac to usb power-pack) and add a voltage boost circuit to get 9v or 12v. I reversed a circuit that uses one small soic8 chip and some resistors,caps and the circuit takes 5v and makes +12 and -12. There are two resistors that can be configured to make any output voltage you want. I can provide that if you need it. To implement it add a switch for usb 5v pass-thru (chips get 5V direct from usb) and the other position joins the usb 5V to the buckreg circuit and that makes +12V. The (minus)12V is there too but you won't need it just use gnd for the VCC minus pin on the opamps. I suppose you could have +12 and (minus)12V as an option if you can figure out how to do it with a switch or something. edit has to use word 'minus' here as using a minus sign makes everything after that strikethrough lol!
I've been holding chips on smd pads and testing them for ~20 years hehe! I have several different working arcade game boards with chips removed and use them for testing specific chips including smd rams. For your little tester gizmo I would add a push button that when pressed latches the vcc and then tests it and the button can be pressed again to stop the test and remove vcc. Put the button in a position so that with one hand the chip can be held in place and the button pressed with the other hand. Or hold the chip with 1st finger and press button with thumb. Or hold with middle finger and press button with 1st finger. Or add a foot pedal option so it can be pressed with your big toe... kind of joking but is might actually be useful to someone hehe! If you use a momentary push button you could latch the signal using some sort of logic IC so there's no physical large button manual movement, it's just a press to start and press to stop. Anyway, with a switch of some sort there's no chance of a short because the circuit is not live until the button is pressed.
I prefer JLC-PCB. Somehow the total costs amount to 3 to 4 times more at PCBWay. On top of that, when I submitted my Gerbers they could not see my bottom solder mask layer. JLC on the other hand had no issue seeing it. The shipping costs made up more than 3/4 of the total cost with both fab companies.
@@LarixusSnydes Well that could be because people don't change the 5 off to 10 off. I use KiCAD and PCBWay have a plugin, you press one button and it is all done for you, you just change 5 to 10 and add to cart. Also if you use KiCAD PCBWay give a donation to the Developers of KiCAD.
Hi Richard, when I watched this video I thought it looked complicated. Why not have a single circuit to generate a signal, then parallel all the sockets? I had a mooch about and found this video, I think it's worth a view. ruclips.net/video/K9Pc8XfAFT0/видео.html
Rich - what a great project! Look fwd to building one and thanks for making it out of discrete components. It would have been SO handy last night to test the LM358 and TL062s that I blew up on my DM6013L "el cheapo" 10 euro capacitance tester (could have been much worse... if it was an more sensitive piece of gear (like me) or the ESR meter or scope, lol...so much for the meter being fused...) . Yep - despite your best warnings about always discharging caps properly before testing, forgot one... - well... late at night sometimes we are not always fully awake. Lesson learned... Anyhow, replaced the op amps and a few transistors and it seems on the road to recovery (the oscillator 8/80/800 Hz is working now thru the ranges) but the output measurement on the LCD is still displaying wrong static values that only change value when the range setting is changed. So I suspect (lots) more cooked components. Of course... cant find a schematic for the DM6013L ... I will order a new capacitance meter but it is a good learning project to see what exactly went up in flames and to see if I can repair it, lol.
Love it Richard - one suggestion ..... tack on the TL494 / KA7500 tester to the same board - cheers !!
Thanks for the suggestion 🙂
Looks like a great idea, for a custom 3D printed type socket. Where you would slide the chip in as you say, with pins taken from header, or mounted on top of two 4 pin headers. I looked up the data sheet for a TL082, and pin headers, and the dimensions work. Paul, USA!!!
no you don't want custom anything. plus it's a 50c chip. you don't spend a year and thousands on equipment to build something that can test a 50c chip lol
@@g4z-kb7ctEven if Richard doesn't have a 3D printer himself, Detlef or another friend might have one. I don't think it's a bad idea. Just a template frame that accepts a SOIC/ SOP chip would be printable under an hour. If you go a little bit fancier you can even build in plastic leaf springs to keep the chip locked during testing.
Hi Rick you can use UV curable board mask and then with several layers you can do it as thick as you want. This way you can also skip the flattening part :)
A simple test for transistors, you could add two multivibrator circuits, one for PNP one for NPN, with one fixed transistor in each version and then test a transistor plugged into the second half. Label the NPN and PNP C B E sockets. Have two LEDs that will flash for each pass result, either NPN or PNP.
Hey Richard this is really cool...sounds like a great project.
love it thanks richard
This is really useful, given all the fake chips that are knocking around these days. I like to test everything before I solder it into position.
If the smd chips are all the same size give or take 0.5mm you can add some smd 0-ohm resistors to the pcb soldered in place top and bottom of chip to give a guide for placing the part with at least 0.25mm clearance to allow for variations in the plastic package. They would be mounted while having an opamp chip in place to get the clearance correct. You can't really put guides next to the chip pins unless it's something plastic otherwise it can cause the chip pins to short together and mess up the testing. I think top and bottom guides is enough. Also be sure to make the smd pads long enough to cover 150mil and 200mil packages. I regularly see LM358 in 150mil and 200 mil so to cover that make the length of the legs fit the 200mil and then extend them towards the middle so there's about a 2mm gap and that will cover 150mil chips.
Yes someting like that should work. Definitely worth a try. Thanks 🙂
Another option to add is a power option. Use a common usb connector for 5v (ideally USB-B... i.e. any common printer cable etc powered from any PC or use a usb power bank or ac to usb power-pack) and add a voltage boost circuit to get 9v or 12v. I reversed a circuit that uses one small soic8 chip and some resistors,caps and the circuit takes 5v and makes +12 and -12. There are two resistors that can be configured to make any output voltage you want. I can provide that if you need it. To implement it add a switch for usb 5v pass-thru (chips get 5V direct from usb) and the other position joins the usb 5V to the buckreg circuit and that makes +12V. The (minus)12V is there too but you won't need it just use gnd for the VCC minus pin on the opamps. I suppose you could have +12 and (minus)12V as an option if you can figure out how to do it with a switch or something. edit has to use word 'minus' here as using a minus sign makes everything after that strikethrough lol!
I've been holding chips on smd pads and testing them for ~20 years hehe! I have several different working arcade game boards with chips removed and use them for testing specific chips including smd rams. For your little tester gizmo I would add a push button that when pressed latches the vcc and then tests it and the button can be pressed again to stop the test and remove vcc. Put the button in a position so that with one hand the chip can be held in place and the button pressed with the other hand. Or hold the chip with 1st finger and press button with thumb. Or hold with middle finger and press button with 1st finger. Or add a foot pedal option so it can be pressed with your big toe... kind of joking but is might actually be useful to someone hehe! If you use a momentary push button you could latch the signal using some sort of logic IC so there's no physical large button manual movement, it's just a press to start and press to stop. Anyway, with a switch of some sort there's no chance of a short because the circuit is not live until the button is pressed.
Thanks for your suggestions
I love PCBWay 😁
I prefer JLC-PCB. Somehow the total costs amount to 3 to 4 times more at PCBWay. On top of that, when I submitted my Gerbers they could not see my bottom solder mask layer. JLC on the other hand had no issue seeing it. The shipping costs made up more than 3/4 of the total cost with both fab companies.
@@LarixusSnydes Well that could be because people don't change the 5 off to 10 off.
I use KiCAD and PCBWay have a plugin, you press one button and it is all done for you, you just change 5 to 10 and add to cart.
Also if you use KiCAD PCBWay give a donation to the Developers of KiCAD.
Richard make a 1.5mm thick mask for the op anp to drop into
Why not use a zif socket and 3 push buttons for power? Would be a lot less wiring...
There are various ways to do this, thanks for the suggestion 🙂
Hi Richard, when I watched this video I thought it looked complicated. Why not have a single circuit to generate a signal, then parallel all the sockets? I had a mooch about and found this video, I think it's worth a view. ruclips.net/video/K9Pc8XfAFT0/видео.html