diy - voltage injection possiblity with voltage and ampere regulator - possiblity ?

[playit]

hello ,for diy voltage injector for short killer/finder -- is it possible to use something like this - LM317 DC Linear Regulator, DC-DC 4.5~40V Turn 1.2~37V, Step Down Power Module, Adjustable

and ampere controller along (to make it zero amps ) with some addons(transistors diodes etc.) for it -- and use some 5v adaptor or 3.3v volt rail of my smps power supply as input and finally get 1v and zero amps for injecting voltage to find out short circuit component ? ..
for source input -- can we use 3.3 -4 volt 18550 battery ?( i have some of those ) and then adding ampere regulator to make it zero as 18650 have some amps 3000mah .. the real machine for voltage injector is expensive for me to buy here. so thought why not think about it of the final result it delivers and could make it diy if possible ..thank you . will make this a new post too , will be very handy in future if this is possible in low cost. thanks

[RethoricalCheese]

Just buy a lab bench power supply capable of 2x5A (1x10A).
1x3A is kinda enough for most cases but I'd recommend more.

But anyway, you have everything mixed up. Maybe because "voltage injector" is kinda misleading. You want power on your short. Thus you need as much current as possible WHILE keeping voltage low. Usually 1V is what you should stick to.

But what I recommend to DIY is cables and connectors for your injector. Buy some good bananas and crocodile connectors and then maybe some silicone cables, as thick as your connectors allow. This keeps voltage drop on your cables as low as possible, thus making your short heating up instead of your cables.

[playit]

RethoricalCheese thank you for replying sir , yes new to electronics , dont know any basics .. in videos i have found out people using voltage injector or short killer with this parameter mostly 1v and zero amp , then applying flux or thermal imaging or alchol or smokers , then they see the changes and remove and retest for short again, but very few videos i have seen people trying to increase a little ampere 1amp to 2 but usually they try increasing voltage to 3-5 v but they did say its dangerous , so yes true, to stick to 1 volt , but current means ampere right ? currently in pursuit in repairing vostro dell 1400 19v short adapter turns off when plugged in problem , so they all found the short with that short killers ,and its expensive here to buy that so was trying to go around ..please kindly take a look at that post too ^^
also i have a working power supply other than the one i am using for desktop , seen it people converting it to bench power supply , so thought of ampere (current ?) control to zero in it "" .
hmm what about this in videos they make both voltage ammeter they make in videos " DC Voltage and amp Adjustable power Supply, Simple DC voltage regulator" so the input to this circuit can be from psu or battery ? .hmm if psu giving ac ? (no idea) can be converted to dc ?? for input sorry being mixing up messy , learning slowly , thank you

[RethoricalCheese]

Without any knowledge, you will most certainly start killing those LM317 before finding any shorts. Since it's a linear dropper, it needs good cooling for example. And that's not all.
Not sure what is considered too expensive in your region but 50€ in aliexpress can get you what you need.

But to answer your initial questions. Yes, you can use anything for input which has higher current rating than you need and has higher voltage than your output in case you are using a voltage dropper. But this answer gives you nothing because what you have between input and output is the important part.

[playit]

aliexpress is banned in my place , thats the problem , also anything above 10$ is really expensive for me.and cant trust anything at my place for sure, they can go bad anytime , thats the quality level at this place unless you buy a crazy branded even that cant trust for fake arounds.i use to get good small things from aliexpress for so cheap, was much helpful , local shop politics dint like it -hence banned.
so using to test that lm317 for even a min and taking breaks in between checking at other sites would still kill it ? in videos they found out short in less than a min though. also i know where to keep the ground and voltage rail for this particular motherboard , they said to keep on side of major supply area part of the board of clr resistor r010 .
yes sir, thats what my question is so using voltage regulator and amp regulator for the 3.3v from my psu or 5v from the adaptor or 3v-4v from batteries aa or aaa or 18650 as input plus adding amp current regulator - i get a voltage injection possible ? . just need some step by step approach and little guidance help .
hmm the circuit between input and output would be this " DC Voltage and amp Adjustable power Supply, Simple DC voltage regulator diy from a video" or analogous to "LM317 DC Linear Regulator, DC-DC 4.5~40V Turn 1.2~37V, Step Down Power Module, Adjustable plus a ammeter regulator along with it (if someone helps how to do that) " -- this cant be used as voltage injector for few seconds to a min close ? with ratings 1v and zero amp as in those videos . ? thank you for trying to teach me sir.

[playit]

found that thsi lm317 have a short circuit protection so when using it for voltage injection it would stop working. so need a power supply source without short circuit protection. so computer psu's would stop too in this case ..found a page on using irf540n ,a voltage regulator and using a battery of cellphone using for voltage injection for mobile pcbs. but my doubt is about ampere incase needed to increase it or lower it ..
will copy paste some lines from there -- 1-CAN ADD FUSE 0F 5 TO 10 AMP FOR SAFETY
2- CAN ADD VOLTAGE REGULATOR
BATTERY MOSTLY GIVE 3 TO 5 VOLTS
BUTT WE CAN RGULATE AND START CHECKING FROM 2 VOLTS
IFF SHORTAGE NOT DETECT INCREAS VOLTAGE 3,4,5....
ITS IMPORTANT FOR BOARD SAFETY HIGY VOLTAGE MAY DAMAGE PRINTS OR CPU OR EMMC OR ANOTHER SO START WITH 2 VOLTS (dono how to change the font color)
btw where to add the 5 or 10 amp fuse in this circuit ? where to where ,please take a look on this , thank you

[playit]

oops dint notice the image wasnt uploaded