Boil water with a solar panel and diodes: Explanation, Complete build & Test #1

[@Teknikverkstan]

Nice! Looking forward to next test. I have 50pcs 20A diodes on the way and my plan is to build a heater to keep our caravan moist free during winter storage. I reckon that sand is good for cooling the diodes and also stay warm for couple hours after sunfall.

[@SolarProjectsSweden]

@@Teknikverkstan Thanks! The prototype is rebuilt and I'm just waiting for some constant sunshine in this gray fall weather for Test #2. What temperature are you aiming for in your heater to keep moisture out of the caravan? Frost-free 4°C or is a higher degree needed? I have also started thinking about different solutions to use diode heat in my house, so there will be some exciting projects to test during the winter.

[@fredericschoovaerts8712]

yes use diode bridges as you will have 4 diodes (2 and 2 in //) bolted on the under pan. Or why not use sand around those diodes to increase contact and make the heat more spread on the surface. Good video !!!

[@SolarProjectsSweden]

@@fredericschoovaerts8712 Yes, the bridges are starting to look more and more like a smoother and perhaps better solution. I used sand in Test #2 and #3 (video available) to distribute the heat and save the diodes. It worked as intended and was also advised that it works with oil aswell. The prototype is now rebuilt for Test #4 and I am waiting for some blue skies in this gray winter Sweden. Thanks.

[@jimw7916]

use bolt on bridge rectifiers

[@SolarProjectsSweden]

@@jimw7916 Can you elaborate on your thought? By a bolt, I assume you mean a metal bolt and a Bridge rectifier are diodes too, but to convert AC to DC

[@jimw7916]

@@SolarProjectsSweden they are a one inch block with a metal backface , containing 4 massive diodes. Perfect for the job. All he needs to do is bolt them to the metal pot.

[@SolarProjectsSweden]

@@jimw7916 That sounds interesting and I'll have to check it out. Thanks for the info

[@canterburyworkshop5631]

@@jimw7916 Can you use these from a DC source instead of converting AC to DC?

[@jimw7916]

@@canterburyworkshop5631 bridge rectifiers are simply diodes.

[@fleaniswerkhardt4647]

What was the point of using all that tape on the outside of the saucepan? Wouldn't it be better to seal the leads of the diodes and place the string in water? That way of course you'll always have the diodes getting no hotter than 100C unless you let the water boil dry.

[@SolarProjectsSweden]

@@fleaniswerkhardt4647 The tape was only so that the cork pad would always be stuck underneath, so I wouldn't burn the table I'm testing it on. It is far too much work to seal the leads on the diodes, but got a tip to cover the diodes with oil which does not conduct current very well. The sand I'm running now seems to work well, both as heat distribution and protection for diodes, so I'll run that variant as far as I can.

[@bigmouthstrikesagain4056]

I'm wondering would old copper rectifiers and selenium diodes work as well? I have a lot of those for free and don't wanna waste money on silicon ones.

[@bigmouthstrikesagain4056]

Also have you tried the industrial ones? The ones that have metal packages instead of ceramic and some heat spreading paste from a computer or silicone to hold them on?

[@SolarProjectsSweden]

@@bigmouthstrikesagain4056 I know that old Copper rectifiers can handle higher amps than Selenium diodes which can handle higher volts instead, but both are a bit too big for what I want to accomplish. My plan is to successfully boil water with a large panel (over 100W) and then fine-tune everything to succeed with a smaller panel, in watts, as possible. The goal is a portable solution to take with you on a hike in the woods or camping. Another viewer suggested the same thing, Bridge rectifiers, but I have no experience with them. Have rebuilt my prototype with 20A10 diodes now and have packed them in sand. If that doesn't work, then I'll take a closer look at these. Silicon diodes are cheap and you can easily find a 50-pack for 10USD. Just connect what you got, measure the voltage drop and multiply it with the amps you're pushing through it and then you'll know how many watts of heat it radiates.

[@nikostsatsis9478]

Why not just resistors?

[@SolarProjectsSweden]

@@nikostsatsis9478 The easy answer is simply that I have knowledge of how diodes work. With resistors I hardly have any idea at all. If my theory with the diodes doesn't work as I thought, I'll have to check other electrical components and it's great when you viewers write your comments, because any tips are good tips.

[@davekisch402]

Great video except for the constant annoying music 😂

[@SolarProjectsSweden]

@@davekisch402 Thanks. As for the music, I let the viewer choose whether they want background noise or whether it should be silent. If something happens in the video that might be funny or useful for the viewer to hear, like here when the diodes popped like popcorn from the heat, I remove the music and keep the sound on

[@misterbarker]

Lose the music and have a sound track.

[@SolarProjectsSweden]

@@misterbarker I hear you and I am now testing a little Text-to-speech in the editing program, so from now on it will be speech in fluent English

[@pr5991]

kzbin.info/www/bejne/amO7epV-dp53rJIsi=wSTLPUf2BspFZLTf he is ahead of you

[@SolarProjectsSweden]

@@pr5991 Yes, Dave at @solarpoweredge is light years ahead of me. I got his video "Research paper: Hot diodes" as a recommendation in my feed shortly after I posted the first video with Test #1. Still going through his material, but we have completely different approaches. He waterproofs his diode string and keeps it inside his insulated mug. My idea is to make it more like a hot plate on a stove, so you can use any pot or pan you want and if I succeed it will be an easy prototype that anyone can copy and build themselves in under an hour.