Capacitor Tester

As a general idea, please note that the capacitor leakage tester project is 1 single project (only). It started small and basic (but a very cleaver and unique idea) and naturally has evolved over time, MCL finding better yet more suitable components for it, increased sensitivity,a wider range, and ultimately a better display by adding a “double” incremental display (with bi-color LED’s). The choice is yours to make. Good luck. PS: Yes the “dual” one is the last iteration (so far!)

It’s best to go back and watch all the cap forecast tester videos before even ordering parts. There are always important details in the videos that would not otherwise be clear.

Dual Display Capacitor Tester Videos 107 and 108

IC1 – End of Life – DigiKey Last Time Buy Date 2025-02-06

The “cruel truth” is that the world of electronics is rapidly changing (like everything else in fact!) and we are forced to quickly adapt to stay on top of the game. The manufacturers and the component distributors are only looking for “Pure Profit”. Nice components that were made for decades and proven to be very good and dependable are often abandoned and no longer stoked or manufactured for stupid reasons such as:  not sold enough, not enough demand (to meet their targeted larger ! profit margin) or, if you are lucky, they  are being replaced by newer a version or by similar functionality products that are often nowhere near as good as the original product. A very good and strongly relevant example of it is the LM723 IC that was used in PSU manufacturing all over the world and now replaced by uA723 that is nowhere near as good as the original. MCL has presented a  2 parts video (one on YouTube and another on Patreon) regarding the matter. Now going back to the Cap Leakage tester discussion, one might need to use a mixture of SMD as well as Thru-Hole components to be able to complete the project (unfortunately) or….keep digging for the now “elusive components”. 

Posted by: @ovi4

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The “cruel truth” is that the world of electronics is rapidly changing (like everything else in fact!) and we are forced to quickly adapt to stay on top of the game. The manufacturers and the component distributors are only looking for “Pure Profit”. Nice components that were made for decades and proven to be very good and dependable are often abandoned and no longer stoked or manufactured for stupid reasons such as:  not sold enough, not enough demand (to meet their targeted larger ! profit margin) or, if you are lucky, they  are being replaced by newer a version or by similar functionality products that are often nowhere near as good as the original product. A very good and strongly relevant example of it is the LM723 IC that was used in PSU manufacturing all over the world and now replaced by uA723 that is nowhere near as good as the original. MCL has presented a  2 parts video (one on YouTube and another on Patreon) regarding the matter. Now going back to the Cap Leakage tester discussion, one might need to use a mixture of SMD as well as Thru-Hole components to be able to complete the project (unfortunately) or….keep digging for the now “elusive components”. 

I am now thinking that I might be wasting my time and money buy parts, only to be stopped not finding all the parts needed.

Now that I am so confused what to do.

I built the Capacitor Leakage Tester many moons ago and has served me well.

I’d like to put a photo of it but I cannot see how to attach images here 🙄 

Posted by: @calambres

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I built the Capacitor Leakage Tester many moons ago and has served me well.

I’d like to put a photo of it but I cannot see how to attach images here 🙄 

You have to share a link to your picture storage by the rules, as a storage problem here on the forum.
I hope this helps.

Try to see what you can and cannot find first and see if you can find alternatives. As “robotwizard” mentioned above it’s worth re-watching videos on older versions and reading comments. In those videos MCL has mentioned some equivalents and when he did that, also some people have mentioned what they’ve tried and what it worked for them as well.  The components used even though they are tried and tested and proven to be most suitable, alternatives should still be available somewhere. When I first built the Cap Leakage Tester, for the first time (back then) I decided to take an easy route and build the thru-hole version of it simply because I had about 70% of the components at hand anyway and only purchased the rest. So what I did was : have actually breadboard it first and got in all sorts of troubles such as oscillations etc etc with it not knowing how to calibrate it to actually make it work . So I didn’t give up and started doing some heavy digging to see what I was doing wrong reading no end of posts and asking around but, once I’ve mastered that and got some promising results I them went and experimented with some other similar  transistors other people’s posts to see what  others have come up with as replacements/equivalents) etc. And step by step I then decided to move on and re-build it properly this time on a proper PCB. but used a fairly different PCB design that was tailored for the components I’ve had. Once the project was done I was over the moon with it and it still works to this day. As a side note: when you make lists of components that you want to buy (that’s if you buy from well known tried and trusted component suppliers) such as Mouser, DigiKey, Farnell etc it is “most of the time” cheaper to buy more than you need and it will certainly pay off  later on when you realize you’ve already got some left for your next project.

It seems to be an uphill battle for me, as I have no SMD’s other than the practice kits I have.

I have started ordering parts and the cost keeps going up.
Now finding the MMBT5962 nowhere, digikey has the BC847ALT1G.

Mouser has PMBT6429,215 maybe a replacement.

Now I do not know what problems connected with the BC847ALT1G will work or not.

I am not very good finding good substitutes.

Hi, Larry, if you go to 108 (on Patreon) Under comments, I wrote you a little something there. it would hopefully point you to the right direction.

Posted by: @ovi4

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Hi, Larry, if you go to 108 (on Patreon) Under comments, I wrote you a little something there. it would hopefully point you to the right direction.

Sure it does !

@larry_n7luf Two different ic’s can be used and there are two different version of each. They are VERY common on Aliexpress and are used in popular voltage indicator for lithium battery chargers. They are not going totally away anytime soon. Good luck!

@ Larry_N7LUF  as mentioned, going over the videos helps.  BUT, at some point, just pick one model and make it.  IF you then decide to make the next model/variation, then you can do that.  Don’t drive yourself crazy with all the variations.  Pick one that you think you can tackle with reasonable effort. 

This is about learning, and enjoying learning electronics.  If you drive yourself nuts, it won’t be fun.  If it isn’t fun, then learning won’t be exciting.  If learning isn’t exciting, your curiosity gets killed.  If that happens, it’s all over.  

When you do decided to buy parts, get extras so you have some on-hand for later use.  

Just my two cents.  Take it with a grain of salt.