DIY Electronics, Tools, and other Projects.

TomXP411 · Post by **TomXP411** » Mon Jan 10, 2022 5:07 am

I found out today that @Perifractic has a page where he posts his favorite tools!

https://www.perifractic.com/takeout-shop/

These are the things he personally uses, rather than just shilling whatever he's getting paid to talk about. (I'm looking at you, Linus Sebastian.)

Strider · Post by **Strider** » Mon Jan 10, 2022 5:34 am

On 1/9/2022 at 11:07 PM, TomXP411 said:

I found out today that @Perifractic has a page where he posts his favorite tools!

https://www.perifractic.com/takeout-shop/

These are the things he personally uses, rather than just shilling whatever he's getting paid to talk about. (I'm looking at you, Linus Sebastian.)

We use the same Thermotronics tip tinner and Easycargo heatsinks I see. haha

What's funny, as if the timing could not be any better, I was literally looking at them just a few hours ago, I am in the market for a good electric screwdriver for light duty and there is one on the list!

@Perifractic, if you don't mind, do you still use that ORIA Electric Screwdriver and what do you think of it? I just want one for PC and small project work, and the pen design is something I would also probably like.

Perifractic · Post by **Perifractic** » Mon Jan 10, 2022 5:42 am

On 1/9/2022 at 9:34 PM, Strider said:

We use the same Thermotronics tip tinner and Easycargo heatsinks I see. haha

What's funny, as if the timing could not be any better, I was literally looking at them just a few hours ago, I am in the market for a good electric screwdriver for light duty and there is one on the list!

@Perifractic, if you don't mind, do you still use that ORIA Electric Screwdriver and what do you think of it? I just want one for PC and small project work, and the pen design is something I would also probably like.

I actually only got it recently. I like it a lot! It’s shown in my next video on Saturday (Tom has early access now hehe). It doesn’t have immense torque but it’s great for smaller items which is the point really anyway. Also for things that need care like putting breadbin C64 case screws back in.

Strider · Post by **Strider** » Mon Jan 10, 2022 6:47 am

On 1/9/2022 at 11:42 PM, Perifractic said:

I actually only got it recently. I like it a lot! It’s shown in my next video on Saturday (Tom has early access now hehe). It doesn’t have immense torque but it’s great for smaller items which is the point really anyway. Also for things that need care like putting breadbin C64 case screws back in.

Excellent, I will check that out!

I use a Skil 4.8V "Twist", it's several years old now and not well suited for "precision" work.

So I want something newer and better for use on project boxes, electronics, enclosures, and other such light work. Plus, $27 seems very reasonable. ?

Thanks for the info!

Strider · Post by **Strider** » Tue Jan 11, 2022 8:01 pm

@TomXP411 Did you find a way to calibrate the output reading on your buck converter? Adjusting the input calibration is easy enough, but doing so throws off the output reading. Using a 9V source, it's off by about 0.20V, and using a 12V source, that discrepancy drops a lot, to just 0.07V. All with it adjusting to output 5V.

I tried 3 sources, 2 were fully charged good batteries. They were a standard new 9V and an APC 12V UPS backup battery (I have a couple of these lying around for the UPS units I use, all are new). The last was the PC PSU's 12V output. The readings were the same. All verified using 2 multimeters I know to be accurate. I did the 9V battery just to make sure the unit was working before digging everything else out (I know the lower the input voltage, the less accurate it can be. ), but I ended up digging it all out anyway. lol

The converter itself is working perfectly, it's just the output reading that's off. I am just nitpicking, since it will always be on the 12V PSU output. I can live with a 0.07 discrepancy just fine. ?

I may just adjust the input reading to get the output where I want it. I really don't care if the input reading is off, since the input source will always be of a known voltage. The output reading is all I care about. I just figured I would ask first, just in case you stumbled across something I missed.

TomXP411 · Post by **TomXP411** » Wed Jan 12, 2022 5:00 pm

That's interesting. Did you have a load on the unit when you tested it? I've found that most regulators will show a high voltage on a DVM with no load.

More to the point, I only use the output voltage on the regulator as a general guideline. What I'm actually interested in is how what the voltage is on my device: in this case, a MiSTer. So I actually testing the voltage on the MiSTer itself by reading one of the GPIO pins. Later, once I put the I/O board back on, I was able to read the voltage from the SNAC port or from one of the USB hub ports. I ended up adjusting the regulator a bit high, so that the USB voltage was as close to exactly 5.0v as possible.

Still, I find it interesting that the voltage reads differently on the regulator based on the input voltage. I'll have to check that behavior on mine.

... and the answer is: My meter is spot on. So maybe there is some tolerance stacking on yours. Yours is a slightly different design than mine, so maybe there's an issue with that specific board.

Strider · Post by **Strider** » Thu Jan 13, 2022 6:53 pm

On 1/12/2022 at 11:00 AM, TomXP411 said:

That's interesting. Did you have a load on the unit when you tested it? I've found that most regulators will show a high voltage on a DVM with no load.

More to the point, I only use the output voltage on the regulator as a general guideline. What I'm actually interested in is how what the voltage is on my device: in this case, a MiSTer. So I actually testing the voltage on the MiSTer itself by reading one of the GPIO pins. Later, once I put the I/O board back on, I was able to read the voltage from the SNAC port or from one of the USB hub ports. I ended up adjusting the regulator a bit high, so that the USB voltage was as close to exactly 5.0v as possible.

Still, I find it interesting that the voltage reads differently on the regulator based on the input voltage. I'll have to check that behavior on mine.

... and the answer is: My meter is spot on. So maybe there is some tolerance stacking on yours. Yours is a slightly different design than mine, so maybe there's an issue with that specific board.

I forgot to mention, yes, I ran it under load just to see, used a 330ohm resistor with an LED. The results were identical.

I am also much more interested in the actual output voltage, and that works great, so the converter is working perfectly. The reading I get on the converter itself is just a matter of convenience. I still use my meter to verify before use.

I did reach out to the seller and I am just waiting to hear back. I will update this when I hear from them. ?

It may indeed just be an issue with this specific unit, or design, either way it still works and I am not all that fussed about a 0.07V discrepancy at 12V, what it will be running at 100% of the time. Nothing I am doing with it will be sensitive to such a small variance. Like I said, I am just curious as to why it's happening.

Strider · Post by **Strider** » Sun Jan 16, 2022 2:33 am

@TomXP411 I think I know why it's happening...

I went in and adjusted the input reading down to fix the output reading, and it worked, and it was then I realized what may be going on.

The battery I was using for testing is a 12V 9Ah SLA, the type used in UPS units, it's actual output is 12.56V at full charge. So that's where I set the buck converter becasue that's where I tested it at. I neglected to check the battery again once I had it hooked up to the converter, and under the load of the converter. This time I did just that, and the battery output drops down to about 12.44V. Low and behold , right where I just set the input reading, and of course I get the proper output reading.

So I hooked the converter up to the PSU I will be using, and it's spot on. The PSU output does not drop off when under load, at least not the loads I am going to be putting it under, not like a battery. So it's working as it should, it was my fault to begin with. I was only reading the output and not accounting for the fact the battery drops off when under load.

Mystery solved.

Guess I should message the seller back and let them know I figured it out. It amazing the silly things one overlooks when they are rushing. Glad I have the next 3 days off to work on these projects. ?

TomXP411 · Post by **TomXP411** » Sun Jan 16, 2022 7:25 am

On 1/15/2022 at 6:33 PM, Strider said:

@TomXP411 I think I know why it's happening...

I went in and adjusted the input reading down to fix the output reading, and it worked, and it was then I realized what may be going on.

The battery I was using for testing is a 12V 9Ah SLA, the type used in UPS units, it's actual output is 12.56V at full charge. So that's where I set the buck converter becasue that's where I tested it at. I neglected to check the battery again once I had it hooked up to the converter, and under the load of the converter. This time I did just that, and the battery output drops down to about 12.44V. Low and behold , right where I just set the input reading, and of course I get the proper output reading.

So I hooked the converter up to the PSU I will be using, and it's spot on. The PSU output does not drop off when under load, at least not the loads I am going to be putting it under, not like a battery. So it's working as it should, it was my fault to begin with. I was only reading the output and not accounting for the fact the battery drops off when under load.

Mystery solved.

Guess I should message the seller back and let them know I figured it out. It amazing the silly things one overlooks when they are rushing. Glad I have the next 3 days off to work on these projects. ?

It's often something simple like that, isn't it? ?

Strider · Post by **Strider** » Mon Jan 17, 2022 3:05 am

That it is... lol

Now I need to build an Arduino based signal generator so I can test out the Espotek Labrador, becasue, I don't own one. I should have everything I need here, and why not, what's one more small project.

I verified it's working just a bit ago by using an Arduino to output a varying PWM signal, ramping up and back down between 0V and 5V, and it works. So far, I guess. There is very little documentation on it so I am muddling my way through it, thankfully it's a really simple device to hookup and use. It has a few different functions and each use it's own pins, so I will end up having to test all of it, hopefully tomorrow.

EDIT: I forgot, it's got a built in generator. ?

So I mimicked a simple test circuit from their highly limited wiki page, and was able to get readings that appear to be consistent. The only issue I have now is getting it fully calibrated. It's readings are ground referenced, and when I ground out the scope pins at the end of calibration, it fails saying it's expecting to see close to 0V, makes sense, that.s grounds to the USB ground, and it still fails to complete calibration. So I need to try a different ground, see if that makes a difference. Still, it's coming along, and it's fun to play with!