Releasing the Magic Smoke

[sternwake]

Released some invisible smoke today, on a inexpensive voltage bucker that had current control too. I accidentally let the output leads touch.  Pretty annoyed with myself.

Got the new 'Andoer' wattmeter, and out of the box it read 0.06volts  to 0.11v low, and is reading low currents worse than my other wattmeters. To top it off it also is as unstable as the windynation in terms of voltage and amperage jumping around, sometimes. snap on ferrite rings had no effect on the instability

I put the windynation 8awg leads  with 45a powerpoles to the circuit board, and am having difficulty getting the plastic cover back on.

The circuit boards of these wattmeter clones are all slightly different.  I've had the best overall luck with the GTpower versions

   

[B and C]

I hate when that happens. You would think I would learn but nope, I still do that from time to time. You are not alone in this.

[sternwake]

What gets me all fired up about this, is I set up some alligator clamps so I could easily hook and unhook leds and fans. I actually made some up specifically for doing this. Usually I slide some large heatshrink over them and just shrink the one side so thay cannot slide off the end of the alligator clip.

But the heatshrink I had remaining was just tight enough in inner diameter, that the clamps would not fully clamp down on 22 awg wire with it slid over. So I used a separator in between the fairly stiff 14 awg output wires to keep them apart. I fired up a powerful 120 fan at full voltage output, without the 4 Lb lead fishing weight atop keeping it in place, and it sucked itself backwards and ripped out the separator and the alligator clamps touched, and that was all she wrote.

But the cursing had just begun. Hope the fan is not fried too.
I gave up testing and experimenting at that point and went and assured Fiona I was not yelling at her.

I liked that specific voltage bucker, it had a current potentiometer that worked as well as the voltage potentiometer for dimming 11 powerful leds, but would allow them to dim even further, and the 40mm fan I have on the same circuit cooling the leds would not come to a standstill at sub 4 volts on the current pot, but would on the voltage pot.
It did not whine at reduced speeds on either pot, like it does horribly on the 13khz PWM LED dimmer.

This specific bucker was only dropping 0.3v at 2 amps of load, so 12.8 in and cranked all the way up, 12.5 out.

Later on I was cleaning my workshop and found 3 older 3 amp buckers with the older LM2596 chip where the newer 5amp buckers have the XL4015 chip.

The smoked bucker had this newer chip. I forget how much the LM2596 drops, but will check soon.

I have employed several of these PWM dimmers years ago, and now some of the lights are flickering when dimmed. Me thinks the voltage buckers will take over the LED PWM dimmer duty. as 0.3 drop from battery voltage is not significantly dimmer and ~92% conversion efficiency is not going to kill my battery measurably sooner.

I wonder If Fiona can hear the LEDs whine when dimmed. I have had some which I could hear when dimmed via 13khz pwm dimmer, but I no longer employ those. I think 180KHZ is above her ability to hear.

Here is a link to the older 2596 3 amp bucker. There are other sellers even less expensive, but this link has very good pictures.

https://www.ebay.com/itm/20V-12-5-3-LM2596-DC-Buck-Adjustable-Step-Down-Power-Supply-Converter-Module/264288295614?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D40719%26meid%3D3743fc57bdcb4e29a6d9c4147177ef8f%26pid%3D100008%26rk%3D10%26rkt%3D12%26sd%3D252811539482%26itm%3D264288295614%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100008.m2219

Here is the newer 5 amp bucker I employ on my 7500 rpm 92mm delta fans:

https://www.ebay.com/itm/20V-12-5-3-LM2596-DC-Buck-Adjustable-Step-Down-Power-Supply-Converter-Module/264288295614?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D40719%26meid%3D3743fc57bdcb4e29a6d9c4147177ef8f%26pid%3D100008%26rk%3D10%26rkt%3D12%26sd%3D252811539482%26itm%3D264288295614%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100008.m2219

Here is the voltage bucker with XL4015 5 amp chip that also has a current adjusting potentiometer, the one I smoked today:

https://www.amazon.com/DROK-DC-DC4-5-30V-Converter-Step-Down-Transformer/dp/B00C4QLK52/ref=pd_day0_hl_23_5/132-4834224-9064111?_encoding=UTF8&pd_rd_i=B00C4QLK52&pd_rd_r=330db765-2d27-4d22-aebb-181a5e45692b&pd_rd_w=uqguY&pd_rd_wg=swAI5&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=49VHNCQWSAFVKCZHBSK7&psc=1&refRID=49VHNCQWSAFVKCZHBSK7

There are many variations of these devices on ebay and amazon, some come with voltmeters and ammeters, and pushbutton voltage/current adjustments. I find the prices to be kind of amazing.

Here are two of the older 3 amp models, 2 for a dollar with free shipping:
https://www.ebay.com/itm/2X-LM2596-DC-DC-Adjustable-Buck-Converter-Step-Down-Power-Supply-Module-1-23-30V/272420115300?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D40719%26meid%3D898b780b1cf04648bd436a20faa5fae5%26pid%3D100667%26rk%3D6%26rkt%3D7%26mehot%3Dpp%26sd%3D173966870938%26itm%3D272420115300%26pmt%3D1%26noa%3D1%26pg%3D2045573&_trksid=p2045573.c100667.m2042

Trying to buy the lm2596 chip by itself is more expensive. So is the heatsink.

It should be noted that if one is going to approach the max amperage of these devices they should have a small heatsink added to the 2596 or 4015 chips. The 5 amp link above shows a black finned heatsink added to the chip in the one pic.

I still have my very first LM2596 bucker that I used n the Silverstone AP182 fan. At battery charging voltages at max speed the hub would get too hot, stinly plstic hot, so I limited it to a maximum of 11 volts, and the fan lasted about 1.5 years failing likely due to corrosion on circuit board from sucking in salty humid air. The bucker still works. that fan is about 1.2 amps at 11 volts at max speed and I never added a heatsink to it.

I have not had one of them fail, other than those that I reversed the polarity on, or touched the output leads together.

[sternwake]

I screwed up a link or two above.

In the following link to post number 107 in my ventilation enthusiast thread, i provided more links to these products

https://vandwellerforum.com/thread-131-p...l#pid52355

[sternwake]

Ok.. more experiments. More smoke. More friendly fire casualties.

On 4th beer. Have 26 pack of Tecate left.

Workshop door is closed.

1800 watts, my ass.

Goodbye gtpower wattmeter. You were a loyal friend.

[Cammalu]

Stern, I need a simple fan I can put by my bed at night. I keep buying those 12v ones with the pinchers on them and they work for awhile but barely give any breeze at all and then they are done.

I need to be able to attach it somehow.

Do you have any easy suggestions.

Thanks

[sternwake]

Ths only plug and play easy product i really know of is those.fans you are.already using.

The endless.breeze fan is.another. i have no.experience with it

Ive no.experience with this.product but perhaps.it will meet your needs.

https://www.surpluscenter.com/Brands/Hup...16-986.axd

I make my own clamp on fans using powerful computer fans on a voltage speed controller on a gooseneck. Parts.alone.are in the 35$+ range

[Scott7022]

I know the question was directed at our resident pro. I have used these in three boats over the years and they all saw a ton of use and sold, working, with the boats. Pricey but great quality. Perhaps Sternwake can comment.
It is a direct 12 volt wire and has built in speed control. No ciggy plug. Easy for JOHN to install.
https://www.amazon.com/dp/B0010UQQRK/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B0010UQQRK&pd_rd_w=bokLT&pf_rd_p=45a72588-80f7-4414-9851-786f6c16d42b&pd_rd_wg=KgtjV&pf_rd_r=DA7R5K0P97YTB82CGRJ3&pd_rd_r=90eda63b-67e8-4b03-9b32-2e8d9ce905a9&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFUMVhYR0VOM05UMkImZW5jcnlwdGVkSWQ9QTA0OTE4NDQxM1pJWUZUWVMyWE45JmVuY3J5cHRlZEFkSWQ9QTA2MjIyMzUzNU5JQ0kxRzNYUE5ZJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

[sternwake]

100 to.130 cfm for .27 amps.is.pretty good.

For comparison a silverstone fm181 fan is 65 to ~155 cfm for 0.1.to.0.27 amps.

But the ss has no blade guards, or mounting hardware. It.is.very quiet.at.full.speed. the ss ap 182 has a front finger guard and upto 1.3 amps and is waymore.powerful at full speed. Mine did not like chargi g voltage at max speed though.

My clamp.fan uses a.92mm fan capable.of.7500.rpm. its over 3 amps.at max speed..but that much airflow.is rather insane. The voltage buck.speed.control can tame.it.to near silence and very low.amp draw.

Being able.to.choose infinite variable.speed and noise and aiming it anywhere is highly appreciated. I also have an airfilter on its back intake side. The filter loads up disgustingly quickly with clothes lint and sheepdog dander

When i come back from a long walk in hot.weather i aim the fan at my sweaty t shirt, crank the fan up to high and have the chills.in seconds.

[CatPerson]

AMAZING!

You know how I tell you guys to keep the electrical instructions very simple for this poor little  ADD-afflicted brain of mine?  Just for fun, I read through these all-in-English posts and all I understood was that Sternwake keeps trying to fry himself with batteries.