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Just a little video till I get some sun for some diversion projects. For low cost AC line operated electronic devices, the capacitive dropping power supply is very common. These can easily be converted to low voltage DC operation. This night light is just an example. I don't know why they made it turn off. There is only a couple ma between on and off. These conversions will be polarity sensitive.

awesome. a few fewer pieces and the switch is now up where those Salt pods once resided. Great

I run mine on 24VDC (Edit) When I bought them, there was also a choice of 12VDC

This is a dirt cheap ($10) temperature control wit the typical features. It has two relays (an added cost) for heat and cool and setting it for either function is not required. It was listed for 110V AC to 220V AC. I intended to convert this if necessary to work on lower voltage DC if necessary. This not only works on DC, but from 15V DC to over 250V DC. The internal relays are 5V. This is the result of a new breed of switchers made for LED lighting.

Really nice project. A modified water thank with two heat elements where you used the bottom one for solar and the top one for domestic electricity would probably give a ROI ( return of investment) in a week or two. Another interesting use would be in a thermal storing cook top (Not sure what it is called in english) Big lump of insulated iron with a 50-100W heating element. It was common over here around 1940-60. Anyway, a comment for the algorithm. Thanks for sharing your insights and projects like this.

Timing is everything. By replacing resistors with a couple of diodes, the cycle times shorten and the delta voltage tightens. With the prior video there was about a 5:1 resistive voltage divider. The enable pin will see a voltage change reduced by that much. Zeners will just subtract that voltage and the delta voltage change at the sense pin will be much larger. That will make the delta swing on the capacitor bank smaller and increase efficiency. More zeners can be added for higher voltage. Even the forward voltage (0.7V) of silicon diodes can be used for a fine adjust. A packet of 100 diodes is cheap. The zeners could all be replaced with diodes. The three 5.1V zeners could be replaced with 24 or more diodes placed in heat shrink tubing. With those exposed to outside air, they will provide temperature compensation to nearly match that of the panels. Seven diodes could replace the 5.1V zener. However, if exposed to the same temperatures the compensation of the other diodes will be negated. If the control is in a more stable temperature area, you still get the temperature adjustment benefits. 10K 1/8W resistors are cheap and allows only one resistor value to be ordered. They can be put in parallel or serial to obtain value needed. The 0.22uF capacitor can be between 0.12 and 0.33uf.

First test of this concept of using a BTS7960 H bridge motor driver to become a high efficiency power point water heater. This is suitable for camps with 24V or 30V array. Maximum open circuit array voltage is 40V with a small safety margin. This test is with a 9 ohm 2,000W 120V heater element. Power supply is set to 22V with a 3 ohm resistor in series to simulate a panel. Capacitance of bank is 6,000uf. Zener voltage is 5.1V to power the HC244 chip on the module. 0.22uF is on the enable input as a noise filter. Diode and 4.7K resistor ensure enable input does not get above 4V. The rest is just a voltage divider depending on array. Min/max swings can be reduced by inserting zener where some of the voltage divider resistors are.

Useful module. Never thought of abusing it as a load switch :)

Wish you would show how to open?

The BTS7960 is commonly used in a H bridge to drive DC motors. Thes assembled modules with heatsink are only about $10 and have an on resistance as low as 7 milliohms, one fifth of a 60A relay brick. It can be controlled with as little as one pin using the enable, PWM is left unconnected since it has a pulldown resistor. In the low position the output floats. In the high state, the output is whatever state PEM pin is. You might want to consider one of these for turning loads on an off with solar. Lot of talk now about PV solar cookers. This would be perfect at getting the most out of a 100W solar panel cooker. This could make the module into a simple camp water heater where the array is 40V or less. 20A would probably be easy for this.

My first test of a 40A DC SSR was a little disappointing with long on delays and high on resistance. This test had me scrambling to see if I hooked it up wrong. There was a lot of noise on the input and the output wasn't even connected. Instead of a photovoltaic transfer of energy to drive the gate, This SSR used an oscillator and transformer operating at 45KHZ. That results in higher energy transfer to drive the gate and faster transitions. Turn on has a 0,75ms delay and off has a 1.5ms delay. But the actual transition speed is quite fast. That makes this pretty good for pulsing a load. Breakdown voltage tested at 269V. I had calculated the on resistance before at 35 milliohms. It was a cloudy day and I was running the dishwasher. I was only able to di a couple amps on the video because the attic inverter runs right from PV and a slight voltage drop turns it off. It took three tries to get this video. If using one of these, it is worth your money to get a higher current rated device.

For better protection of that battery.. maybe add 1s bms on the cell? I am thinking in case the 5v supply fails and puts 10v . Anyway keep posting videos , I enjoy them:)

This circuit will power the control of direct connect PV water heater using a solid state relay, a 5V cell phone charger and an 18650 lithium battery. Most arrays will be above 60V and that is enough to power most cell phone chargers. The 4.2V battery is enough to power the 3-32V SSR and prevent it from entering the 2V region in the early morning which will destroy it from overheating. Most relays draw from 5 to 10ma, a minimal load for the battery. Cell phone chargers are about 5.2V and that voltage must be lowered not to exceed 4.2V on the battery. Two diodes in series drop the voltage approximately 1.4V. That ensures the battery won't drop below 3.7V. A 27 ohm resistor across one of the diodes provides a little extra current to get the battery voltage above 4V. Old 18650 batteries are easy to find in old battery packs and everyone has an old cell phone charger. This makes an easy power source for a solid state relay.

thanks for sharing

I got one of those hot water controller form that guy and he went out of business again I have to put up some new panels for it

Direct PV power runs my Ryobi clone battery charger. This is rated for 100 to 240V AC but it works down to 60V DC from my PV array. It worked as is because it has a switching power supply. From experience I know these switchers will work that low and sometimes they need a little help starting. I bridged a 2.2M ohm resistor across the two 1M ohm boot up resistors to make starting easier. With this modification the charger will still work with 120V AC. Just another way to not have to run an inverter. 60V is always available in the shop. Most devices never have enough air circulation. I cut the internal vent bars to make air easier to move. At lower voltage, the internal inverter will run a bit hotter. These are projects I do and are not recommended for those without a technical background.

Just over 800w of solar will give me 1.6kwh of free power, with used panels facing south on a sunny uk day, welcome to the real world buddy 😂

You show the difference between that it works and how it works and how it works is always the way to go. If you don't like what you see it can be improved until it works how you like it.

This what they don't tell you about using a buck converter with a solar panel because they are just box openers. Buck converters are designed to work from a low impedance source like a battery. The input capacitors are just large enough to keep the electronics stable and not oscillate. Many have a label warning not to use them with solar panels and inverters. This test with a 100W solar panel is not in full sun and can only produce about 30W. Even then there was a peak ripple of 7V. That ripple voltage can destroy a capacitor over time and these modules are all potted. MSW and sine wave inverters draw maximum current at the peaks. Just like my water heater designs, Power needs to be stored at these minimum draw periods. The inverter can then have the added power of the capacitor and the solar power. Otherwise, this power is just lost. When used with a solar panel, 10,000 to 15,000uF capacitors are needed across the solar panel for longer life and added power capability.

Lovely. I love systems like that

Some like watching repair videos. This likely left the factory not working after they attempted to repair it. Looks like the transformer was hit and the foil on three terminals lifted. One was obviously damaged and after that didn't fix it I kept working down the line. There were signs a repair was attempted and maybe it worked for a short while. Intermittent problems can be tricky. To make matters worse they likely had trouble putting it back together and the battery terminals hung up and the foil lifted. This was a really crappy single sided board with a poor trace layout which is really weak. If it wasn't for the SMD parts this would look just like the 1980's crap from China. This design isn't smart enough for proper charging and long battery life.

👍

Direct Power seems to be the new buss word on YT. I've been doing it for years and it greatly reduces battery and inverter requirements. My inverter only runs when the fridge is on. On this video I use a 120V to 12V switching power supply in series to boost my 12V battery voltage to 27V. The wall mounted buck converter reduces that to 21V. A resistor limits charging current to the battery pack of soldering iron. A LED warns me if charging goes over 360ma. This is a simple battery pack which does not have communications with a charger. This is part one and I will cover in other episodes how to direct power from solar panels an old MSW inverter.

It works great when it works. The problem with the device is over time the sinus rinse solution gets past the pump and down into the motor. This causes the top bearing in the motor to corrode and stop the motor from spinning.

Hi there 🎉

Turns out these pencil irons are phase triggered and don't like MSW inverters. I had plugged it in and the display did all kinds of flashing, then nothing. Internals wouldn't slide out till I removed nameplate and silicone buttons. Found what seemed like a tiny glass fuse open. It is actually a chemical thermal fuse. Replaced that with a 3A pigtail fuse I had in stock. Works fine now.

i put a computer fan on the out side of the controller the controller never runs

Just how fast can you turn on and off a SSR with internal IGBT? It takes about 1.3ms before it even starts to conduct any current. Total time to turn fully on is about 10.4ms. However, turn off is extremely fast. Switching speed is limited to about 15Hz for practical purposes. These are not very fast at all and could experience excessive heating when switched fast.

This video covers turn on voltage and saturation voltage of s 40A 220V DC SSR with an internal IGBT. Turn on starts at about 2V. LED will not light at this voltage. Relay will not turn on fully and there will be a high saturation voltage with just a couple amps leading to excessive heating. Good news is under 5A the ON saturation voltage can be only a couple hundred millivolts instead of almost 2V.

I've been thinking about running more things directly from DC, like the new inverter air conditioners. You trust these things not to catch fire on you?

Can thst circuit handle up to 400dcv . Just want to know because I want to use it in my project

IS THE FET NCHANNEL OR CHANNEL.

Huu, nice tip! Your absolutely right. The sleeve spinning can drive you absolutely bonkers 😂

It might seem like a small thing but those small cheap allegator clips drove me nuts for years. Try and attach them and the clip would spin in the insulated jacket. I thought if I just cleaned the insulator, it might remove any release agent used in molding. That never worked. I found that roughing up the outside surface made all the difference in the world. Rougher the sandpaper the better. If my paper is too fine, I'll hit it with a file to make some deep ridges. It makes all the difference in the world. I like using these small clips in tight spaces. I just got a batch of these small allegators in and was making some test leads. Thought I would share this little tip. I have never seen this tip mentioned anywhere else.

As I promised you, I made a hot water controller from this LM393 temperature control board with four resistors and a FET. It works, it doesn't have all the features of a good control with arc interrupt and wouldn't recommend it for really high power. But it works and for less than $5, not including the capacitor bank. I might pursue this further, maybe not. There isn't much interest in building things on YT. There are three other water controllers on this array along with the charge controller. That is the reason it is difficult to keep an image. Adding a pot in series with the sense voltage would give finer control. I might set up one of my small 3 gallon tanks and four 100W 12V panels in series to show how easy it is to get hot water.

Did you add insulation to the freezer? My freezer has the hot part at the top so I figured I can save some energy by insulating the bottom part. Newer came around to do it thought. Handy little circuit and nice way to use it. I can see myself using it to draw cold air into my fridge-box at night if temperature inside my fridge-box is higher than outside. Should not need much of a battery to do that. Anyway, a comment for the algorithm. Thank you for making and sharing this 🙂

Hoping to see you do more videos in 2024. God bless!

My converted chest fridge only runs in the daylight hours from PV. Every morning there are long run times to get the fridge down to temp. These were designed for short intervals where the motor was used to dissipate some of the heat. I want to cool the motor so it becomes more efficient. This circuit powers the muffin fan till temp drops. I'll hang the fan with some magnets for a no drill install. Fridge does not have to be on for fan to work. This is a common board for small micros. It could also be adapted to make a PV power point water heater. We will try that in a future episode. A simple dropping resistor provides voltage to power the board. The power on LED and 1K resistor form the major load till the fan comes on. Then it is another identical load added to that. This is not stable, but the bridge circuit is pretty much immune to voltage changes. This comparator has no hysteresis and can get a little noisy on transitions. A PNP transistor has to be added for higher drive and to invert operation. A zener provides offset voltage so it fully turns off. In a PV power point water heating application this board could drive a FET directly making a pretty simple build.

Used mine for a year, and today it died. Not batteries, they were changed earlier in the week. Not salt, I rinse it thoroughly after every use and let it dry. No, poor design. I got it apart easy enough - a small screwdriver in the centre of the back seam popped the two halves apart after the long screws were undone. All inside was fine, but as I saw from early on, the battery compartment has no formal compressible seal, consequently water can find its way into the area corroding the terminals. I’ve been keeping them clean, and a while ago applied a thin film of Vaseline along the battery case joint to keep the water out, but it’s not perfect, consequently when I got it all apart it was all clean, no salt, I could spin the motor up with a spare battery attached to the terminals, but inside the connection area, which you cannot access there is clearly a connection problem. Yep, poor design. I’ll buy another as it really does work for me, but before use I’ll run a thin bead of non-setting sealant along the battery tray joint before screwing it down. A small neoprenes gasket in this are would likely solve the problem. Would have cost pennies. You live and learn.😏

I had been searching for a suitable E26 base low voltage lamp for my garage for years. I had used a harsh white assembly mounted on the back of the fixture. Now I found the perfect solution. These lamps are for string lights wired in series. Each is 3V 1W with a single LED filament. I put the two sockets in series and threw in a 33 ohm resistor in case anything goes really bad. There is a small buck converter that drops the voltage down to 7V. The 12V draw is only about 60ma.These are left in automatic operation for the 7 months I am not here along with an 18 inch lighted mouse in the upstairs window. With the brass it gives a wonderful warm glow. and the single filament looks like a candle flame. I will be doing the same thing with a desk lamp putting three in series.

First video of 2024 camp season and it is HOT. Starting off with a couple mundane videos. I remove the fans from many electronic devices to lower standby current and noise. I let natural convection do the work. That can't be done with some devices and I move the fans to the outside for better airflow. Most times the fan is jammed in too close to circuit board and other components restricting airflow. The reason manufacturers do this is for more economical shipping. Relocating fan outside the cabinet dramatically increases airflow and sometimes noise associated with that dramatic increased flow. I think it is worth it..

I haven't seen mine for a year. It never worked that well for my nose problem. These don't need screws to hold them together. At 4:34 I show the tabs. The tab side of the housing needs to be pushed in to get it to release from the other side.

How did you get it apart? We cannot get to the inside of the thing after removing screws.

Today's standard PV like the China's 550watts having a Voc of 51.9volts x 2 = 103.8v if in series. It is just barely above the MT4010 maximum PV voltage input of 100v. Will it safely accept the input voltage safely (103.8v) instead of setting in parallel connection? Well we knew the economic and safety advantage of wiring lower current.

My god after listening to your presentation gave me a severe bought of depression

Hello, i am interested in updating my Sun MDT machine with your dwell module, do you have one available? Thanx, Tom

Upcycling gives used parts a new purpose, do it whenever possible. Also replacing failed parts with more capable parts prevents same failure in the future.

This can be done in low voltage and in a more modern style with an Arduino driving some SSRs on 3 digital pins. SSRs have to be the 2 - 32 volt DC control type that switch 85 - 320 VAC. The good thing about this way is everything is low voltage and would be programmable. The SSR's will also isolate the line voltage from the low voltage MCU stuff.

Anyone car repair electronics using the correct part. And what fun is that? This is how you can make do with whatever you find in the pulled parts box. This board is used to provide sequencing for an old traffic light used as a display. I had a transistor the right physical size so I tested it on my handy voltage breakdown tester. Transistor tested at 253V. That is cutting it a little close, would prefer over 400V. Figuring this is at an industrial property and the voltage could be 135V, the transistor will regularly see 190V peaks. I put a 150V MOV across the AC input. That will start conducting about 220V. On the output of the bridge rectifier a .22uF X2 capacitor was installed to absorb any spikes. I didn't bother looking up the current rating of the new transistor, figured it would be about 1/2A. The 60W incandescent lamp will be replaced with a LED. That will make the current about 1/10A. No need to worry about current. The string of LED in the lamp will also subtract at least 90V from what the transistor will see. Working the problem allowed me to use what was available and quickly turn it around. All parts were pull outs that cost nothing.

Many power supplies use a TL431 to control output voltage. These can be made adjustable by changing the ratio of the voltage divider. This can not be a full range adjustment because the output voltage supplies power to the TL431 and voltage can not exceed output capacitor ratings. This supply had an internal 1K pot which I replaced with a standard adjustable pot. A hole was already made in the front plate to install it and a 1K pot was an item I stocked. That gave me a range of 11.5V to 13.8V. I needed lower voltage to test an inverters shutdown circuit. I could have easily ordered a 2K or 2.5K pot to get the range down to 10V. Instead, I tied a 33K resistor from the pot to the output voltage. That gave me sufficient low voltage by supplying a slight additional current to the sense pin of the TL431. No need to order a special pot. I could have also raised the upper voltage limit by draining some current with a resistor from the adjustment pin of the TL431 to the common minus of the output.