I really enjoy that you don't necessarily do these projects to create the most optimized, low cost, or practical applications. Rather, you create these wild and creative projects for the pure love of electronics and interesting circuitry. Something I don't think a lot of commenters quite understand yet. 😋
I would use only one powersupply, and have some sort of switch which would switch in or out a different resistance network on the current limiter potentiometer. So one charge mode have the relay off, once you want to switch to the other mode turn the relay on and add resistance in parallel to the potentiometer which will switch it to your target rate for that mode (I don't know specifics so don't know the exact functionality to design that, I said relay since you could get a dual pole one but use a mosfet if you prefer)
My thought exactly, as the current sense is on the low side just fit a resistor to give you the low power output. Then the LED are not illuminated shunt it with a lower value to provide the high current output. Then there is no need to worry about blocking diodes of which you need one for each PSU, the power losses and heat in the diode on the high current side. 2A charge is going to be 1.2W’s loss in the diode. Let the sense resister take all the strain with very little volt drop. There are times when the "modular" approach is not the best idea :)
I'm glad you're taking the time to record your power supply sharing shenanigans Julian. I did much of the same experiments on those pseudo MPPT charge controllers for my solar accumulator project, but unfortunately didn't record most of the experiments. I was looking to charge 18650s from solar, at moderate current levels, but with caps, you can charge much more aggressively. Nice to see it working. Good to see you working in the new modular shed too. The best thing I did was to move my working area from the under stairs cubby hole, out to my newly refurbished 12'X15' workshop. It's so convenient to be able to make noise, smells and leave a project out, without complaints from other family members. ;)
Actually only need one transistor. Find the resistance that sets the high current limit, and the low current limit. Two resistors in series add up to the higher of the two, one resistor equals the lower of the two, and a MOSFET shorts the other one. Done.
I feell so scared when you don't immediately turn off the power source when the 2nd power supply goes negative. Is the shed rainproof now? Will you be able to sit in the shed during the harsh english winters ?
I worry less about such things as I get older :) Water shouldn't be a problem in the new shed (super thick roof panels /large overhang). Making it warm will be my main focus come autumn. Already bought a roll of insulation to play with :)
Interesting to see how the 2 DC DCs interact. For a simple 2 stage charger I think I would use a single DC DC with 2 pots to control the current (& or V) with a change over relay. In your set up tying MOSFET gates to the LEDs to control the relay. As a side note I replaced an old faulty linear voltage regulator circuit in a caravan PSU / battery charger with a 10A DC DC (transformer - rectifier - capacitor - DC DC - battery). When the AC was turned off, it quite dramatically blew a large capacitor from back feeding, filling the van with smoke. The DC DC was to hot to touch so since then have always used a blocking diode.
Julian ! Its so much easier to just use one PSU, change the CC pot to a couple of resistors, fit a tiny fet or similar to sense the charge led on, that modifies the CC resistor values. Then there would be no issues with the two PSU's, affecting each other and negligible switching time from high to lower current.
Hi Julian! I just wanted to say I'm watching your channel from nearly bunging... AND I think there is a fundamental flow in your setup. YOu need a a galvanic isolated power supply to ich converter to get this work. //Regards from Sweden
So, I'm only about 9 minutes through the video, but I'd like to suggest just using one converter, with an Arduino (or clone), a digital potentiometer, and a voltage measuring circuit. You can then set the potentiometer value based on the voltage, you could have a current curve, or whatever you want. Nearly finished, brilliant solution with the blue leds. Great video as always, thanks Julian!
What about only using the high power psu, but remove the voltage pot, put 2 pots on a separate board along with a trasistor, the idea is that when you need full power, both pots are in use. but when a led lights, only one of the pots is in use giving the lower voltage If you want to put a led and opt in parallel, add a series resistor to the opto, and connect in parallel with the red led and opto.
This is what I was thinking. I wonder If the pot is used to make a voltage divider like if the center of the pot is at some voltage and that voltage sets the current. If that was the case, you could replace it with an analog output of an Arduino (with some filtering) which is also monitoring the protection circuits, you could programmatically control the current any way you want.
I was trying to make it simpler ;) From what i've seen, i think the pots are just selecting a resistance in the feedback loop, nost smps are resistance to ground, not a votage divider.
I wouldn't keep anything of overt value (like power tools and batteries) in the shed. Unidentifiable gizmos strung together with wires are less likely to be stolen - I reckon :)
You've found exactly the problem I had when I wanted to use these in a vehicle. The common ground makes current detection impossible. And unless you can find some way to exactly balance the output voltages they won't current share either; the device with the higher voltage output will give all the current, and without backfeed diodes will reverse feed as you found. Edit: of course, what's really needed is buck/boost converters which perform current detection in the high side but that's much more tricky to implement. I'm not sure anyone makes them other than just detecting a short condition.
Way too complicated design. You waste alot of energy charging those capacitors with 2 PSUs. You already have protection board on them, so why not just charge them at the nominal current?
@Steve Cooper - That's right. Also, supercaps have poor energy retention, so the pack will always be discharged when you come to use it. A 2 or 3 minute charge time would be about right.
That's the whole point Julian takes a simple project complicates it as much as possible with as much hardware he can fit on his bench then spends a few videos troubleshooting looking for a solution, he reminds me of my local council highways dept makes you travel a long convoluted journey but not achieve any distance, very entertaining and colourful but pointless. here;s a quick fix stick a battery on it.
@@surfaceten510n Julian should work in the electronics department at a German Auto maker. Wonder´if any of them are looking for any Over-Engineers at the time. LOL
One PSU connected to supercap bank via a mosfet, controlled by an Arduino connected to balancer LEDs, with a baby 128x32 OLED to show balancer and supercap state. Problem solved, visually appealing and more informative. If you want to get fancy, you could probably use three P&N Si4599 mosfets to charge the individual super-caps directly in sequence, since you can cut both the positive AND negative connections to each? 6A rated, so 2-3A should be just the ticket! :)
The DP30V5A DC power supply voltage & current regulator would do the same thing for you all in one. You just dial in your voltage and current, when it reaches what you have chosen, it will trickle charge or shut off. But I think you're just having fun with modules! :-)
This really does seem like using a wrecking ball suspended from a crane, to knock over a domino. Can you explain why you’ve decided on such a complex charger when as far as I can tell, a single voltage and current limited supply would be fine, as long as the limits are set correctly.
Wrecking ball / domino - that would be 17 power supplies ;) I want to charge the caps at a high current (let's say 10A) then wind that back to 0.5 amps when the first capacitor hits top.
Julian Ilett Yeah true, although maybe you could use 17 supplies, in 100mA increments 😂 Wouldn’t a typical buck / boost supply achieve the same result of high current charging and low current ‘topping off’? As the voltage rises, the current would naturally fall, and once it hits voltage limit, it would drop substantially. Personally when I wanted to charge a large super cap bank, i used a typical lab bench supply with appropriate voltage and current limits and had no issues with overcharging, I however didn’t have the ‘current shuffle’ boards
A CC/CV power supply can only respond to the overall supercap 'pack' voltage. I want a PSU that responds when any individual capacitor reaches top, and winds the current down substantially and instantly.
A rolledup tube of cardboard around the red led and a photocoupler or light sensing transistor in the other end of the tube facing the red led should allow switching when the red led turns on.
I found this video very insight full i just have a burning quetion. Since the Converters are connected in parrallel why is the current not summend on output?
Would this not be a good use case for some "Ideal diodes" sure I remember them from a post bag a while back? Also have an alteria motive as just ordered some as want to experiment with a DC backup power supply. With solar 12V+ and a back ac2dc set just under 12v for if solar voltage drops. And Ideal diodes if they work
Why not have an arduino control a bjt which adds a second shunt resistor to increase the current of a single supply. When the balance voltage is reached is open the bjt and the shunt is returned to normal
For charging I'd be likely to just use a high current-limited power supply at "VPack-.2" and a low current-limited power supply at "VPack" They would both charge when "
How about single power supply with two different resistors in place of the variable one switched by an arduino? Or one of those arduino controlled variable resistors? (X9C103S)
That's what I would do. Using an arduino mini with the gpio's connected to where he has the red led's, to tell when to switch to low current mode. Of course you probably could just use transistors to get the same result.
@@ianhaylock7409 Yep, no need for microcontroller, I think it could be made to work with couple optoisolators and resistors, maybe a transistor or two.
You could create a circuit that would utilize the opto isolator to adjust your output amperage on one power supply by adding or removing a resistor to the adjustment pot.
Either two Schottky diodes (with drop compensation) OR putting a, possibly opto-isolator driven, switch to toggle between the supplies so that when any lights come on they trigger the switch to kick over to the 0.5A supply while turning off the high-current unit would do the job I think. The diodes would be far easier, but the switch would be dumb fun and a more fun solution.
Why don't you connect 8 volts across the protection devices and let them do what they are designed to do? Perhaps using simple precision resistors instead of a catch 22 balancing circuit might require less complications.
How do I apply for a job for Ilett Corp when you take over the world with your supercapacitors? In all seriousness, I've learned so much watching you and Big Clive these last few years. You both have really done a great job explaining electronics so it's easy for people to understand. Things have clicked for me and linked things I learned in elementary school with how companies implement things in products and all their electrical circuits work together.
Or put a Schottky diode in series with the opto to raise its voltage to match the red Led. Will add about 0.2v which might be enough to match the red with the opto's infra red.
Wouldn't a constant current constant voltage charger do the same thing? You just set to the voltage you want & max amperage you want. It charges at that Max setting. Then like a lithium ion battery charger, when it reaches full ( whatever you have set as max) it will trickle charge after that & just maintain.
Wouldn't it be easier to use some combination of resistors and/or transistors connected to the LED signal from the capacitor bank to change the current setting on the PSU, so you can use one power supply instead of two? Haven't thought this through or finished the video so I may be completely off, but it seems like a nicer solution in my head
I like thinkering like that but why You can't set highamp psu set with voltage just bellow max voltage caps can handle. It will go down with amps anyway and then the lowamp psu will take the load. I understand that this is safety with opto idea but there will not be so much diference in voltage betwen caps like You created with shorted one in normal use. If there will be that diference then it is something wrong. At least it is my understanding
to me it's logical that the one goes negative which is set lower and the higher set module get even higher because you can't current share the way you want, when you want to do current sharing you have to set both modules to the same current otherwise you aren't doing any current sharing. You wanted to have the higher set module to do the first step then the lower set module kick in when the first module stops, the only way to make that possible is to control the modules separately via relais to isolate the two. It's either one or the other, you can't do the two at the same time, it will never work.
That's not too bad actually, especially as it will probably average out at a lot less as most speakers are rated at PMPO rather than RMS output, My guess is that it will use around 5 to 7 Watts before you hit distortion, so you may find that it will run for around 25 mins or so, Coupled with a very fast recharge time that's really not too bad, I was expecting 5 minutes or so to be honest
You need diodes on output of PSU's preventing Back feeding between the PSU's ! Again use a Shunt connected to each PSU to better allow them to share loads. The Shunt works to steer the current more towards the load.
@@drkastenbrot It is a more or less inherent part of every switch mode power supply. This one however is special, because it is everything but a simple step down or step up converter. See the datasheet for details: www.analog.com/media/en/technical-documentation/data-sheets/LTC3780.pdf Bear in mind that FETs do have a body diode that may become conductive unter certain situations.
@@drkastenbrot Not these chines toys. Well most don't. Some they actually tell you to install one. If the PSU looses it's source they back feed from the battery and go to PSU heaven.
@@blubbspinat9363 I played with these for a Wind Turbine set up. Wish I could find one better then just 3-5A. That's how I learned about the Shunt Trick. They will back feed without the diode across from each other if the drain or load is disconnected from them charging. They shouldn't because the load is gone and you would think they would stop supplying current. Guess they see each other as the load.. Not quite sure how the Shunt works with the sharing but it does. You can get two parallel units to track each other quite well.
Confused here. Why are you doing this ? The PSU will end charge when your set voltage is reached. If you have the PSU set for 2.7v per cap it won't go any higher. You have a Balance system in place.
The really cool way to fast charge a capacitor bank, in my opinion, would be to do the fast part from an even bigger capacitor bank, bypassing all the electronics, because you could do a large part of the charging in a couple of seconds, without any risk if you parallell every "step" like the active balancers are connected here. The chargers capacitor bank could then just have nice careful charging always connected, that will keep it charged, and could charge the speakers capacitor bank the last part more carefully if it is just left charging. Crazy expensive, I know, to have 2 or more times the speakers capacitor capacity in the charger also. But lets be honest, if this was for practical purposes, in order to be able to charge fast, you could've used a power bank that can take quick charge. That way you could get more powerful charging, than those
@@JulianIlett That has to be a bonus for a youtuber :) No, seriously, I was counting on wiring giving a bit of resistance, and even supercaps can't dump all their energy absolutely instantly, and having voltage difference of just up to 2.5V seemed unlikely to me be able to create any huge shows, or significant safety issues. If I'm wrong a video correcting me should be a popular video.
couldnt you use a PIC or arduino to vary the current on one of those boost/buck boards? when it senses a certain voltage adjust the current accordingly. you could have multi stepped charging that way. Im not really sure how to vary the restistance on the charging board to change the current value though. maybe a relay and the NC output of the relay could have a resistor that sets it to 2 amps then when it hits a certain voltage activate the relay that has another value resistor to limit the current to 0.5A on the NO side. I love these kinds of projects!
Not many boost converters work down to 2.5V on their input. To extract a useful amount of energy from the capacitors, the system would have to keep working down to 1V or so per capacitor.
I really enjoy that you don't necessarily do these projects to create the most optimized, low cost, or practical applications.
Rather, you create these wild and creative projects for the pure love of electronics and interesting circuitry. Something I don't think a lot of commenters quite understand yet. 😋
Thank you very much!
The modular approach is taking over Julian’s world what ever next, two boxes to house it all :)
I would use only one powersupply, and have some sort of switch which would switch in or out a different resistance network on the current limiter potentiometer.
So one charge mode have the relay off, once you want to switch to the other mode turn the relay on and add resistance in parallel to the potentiometer which will switch it to your target rate for that mode (I don't know specifics so don't know the exact functionality to design that, I said relay since you could get a dual pole one but use a mosfet if you prefer)
Exactly what I was thinking. Use one PSU and use the opto feedback to change the current by way of the preset resistor.
99% of people would use a single PSU. I am the other 1%
My thought exactly, as the current sense is on the low side just fit a resistor to give you the low power output. Then the LED are not illuminated shunt it with a lower value to provide the high current output. Then there is no need to worry about blocking diodes of which you need one for each PSU, the power losses and heat in the diode on the high current side. 2A charge is going to be 1.2W’s loss in the diode. Let the sense resister take all the strain with very little volt drop. There are times when the "modular" approach is not the best idea :)
"To disable the automatic power-off feature, press and hold down any button while rotating the mode selection dial from OFF position"
Indeed :)
I'm glad you're taking the time to record your power supply sharing shenanigans Julian. I did much of the same experiments on those pseudo MPPT charge controllers for my solar accumulator project, but unfortunately didn't record most of the experiments. I was looking to charge 18650s from solar, at moderate current levels, but with caps, you can charge much more aggressively. Nice to see it working.
Good to see you working in the new modular shed too. The best thing I did was to move my working area from the under stairs cubby hole, out to my newly refurbished 12'X15' workshop. It's so convenient to be able to make noise, smells and leave a project out, without complaints from other family members. ;)
Marvellous video. My attention was gripped and enthralled all the way through
I think a couple of transistors to switch between 2 charging modes on a single power supply would be much more attractive?
Financially more attractive maybe - but visually less appealing :)
@@JulianIlett If you use a relay to switch the current of a single supply it will be sonically more appealing.
If you hire a person to manually press the button it will be better for the job market
Actually only need one transistor. Find the resistance that sets the high current limit, and the low current limit. Two resistors in series add up to the higher of the two, one resistor equals the lower of the two, and a MOSFET shorts the other one. Done.
I would go along with this idea, but I would use a second pot in parallel and switch that in or out of circuit.
Kirchhoff's laws explains this perfectly.
I feell so scared when you don't immediately turn off the power source when the 2nd power supply goes negative. Is the shed rainproof now? Will you be able to sit in the shed during the harsh english winters ?
I worry less about such things as I get older :)
Water shouldn't be a problem in the new shed (super thick roof panels /large overhang). Making it warm will be my main focus come autumn. Already bought a roll of insulation to play with :)
@@JulianIlett LOL . ah OK good luck with the insulation job. I'm sure you'll make new vids about that :)
Interesting to see how the 2 DC DCs interact. For a simple 2 stage charger I think I would use a single DC DC with 2 pots to control the current (& or V) with a change over relay. In your set up tying MOSFET gates to the LEDs to control the relay.
As a side note I replaced an old faulty linear voltage regulator circuit in a caravan PSU / battery charger with a 10A DC DC (transformer - rectifier - capacitor - DC DC - battery). When the AC was turned off, it quite dramatically blew a large capacitor from back feeding, filling the van with smoke. The DC DC was to hot to touch so since then have always used a blocking diode.
Julian ! Its so much easier to just use one PSU, change the CC pot to a couple of resistors, fit a tiny fet or similar to sense the charge led on, that modifies the CC resistor values. Then there would be no issues with the two PSU's, affecting each other and negligible switching time from high to lower current.
Hi Julian! I just wanted to say I'm watching your channel from nearly bunging... AND
I think there is a fundamental flow in your setup. YOu need a a galvanic isolated power supply to ich converter to get this work. //Regards from Sweden
So, I'm only about 9 minutes through the video, but I'd like to suggest just using one converter, with an Arduino (or clone), a digital potentiometer, and a voltage measuring circuit. You can then set the potentiometer value based on the voltage, you could have a current curve, or whatever you want.
Nearly finished, brilliant solution with the blue leds. Great video as always, thanks Julian!
What about only using the high power psu, but remove the voltage pot, put 2 pots on a separate board along with a trasistor, the idea is that when you need full power, both pots are in use. but when a led lights, only one of the pots is in use giving the lower voltage
If you want to put a led and opt in parallel, add a series resistor to the opto, and connect in parallel with the red led and opto.
Well, I probably would do that if my manager was yelling at me to reduce the BOM cost. Fortunately, I have no manager :)
@@JulianIlett Oh ? i thought you were married :D
This is what I was thinking. I wonder If the pot is used to make a voltage divider like if the center of the pot is at some voltage and that voltage sets the current. If that was the case, you could replace it with an analog output of an Arduino (with some filtering) which is also monitoring the protection circuits, you could programmatically control the current any way you want.
I was trying to make it simpler ;)
From what i've seen, i think the pots are just selecting a resistance in the feedback loop, nost smps are resistance to ground, not a votage divider.
Nobody ever told me I shouldn’t have things of value in a shed. Eek! Anyway, I like the new location Julian.
I wouldn't keep anything of overt value (like power tools and batteries) in the shed. Unidentifiable gizmos strung together with wires are less likely to be stolen - I reckon :)
Congrats. This has to be the first project you finished.
LOL
Projects are never finished. There's always something that can be improved :)
You've found exactly the problem I had when I wanted to use these in a vehicle. The common ground makes current detection impossible. And unless you can find some way to exactly balance the output voltages they won't current share either; the device with the higher voltage output will give all the current, and without backfeed diodes will reverse feed as you found.
Edit: of course, what's really needed is buck/boost converters which perform current detection in the high side but that's much more tricky to implement. I'm not sure anyone makes them other than just detecting a short condition.
Julian's project... finished? Who are you and what have you done with the real Ilett guy?
RUclips must like your content. I had 7 ads play in a 27 minute video. It was almost more ads then video.
Way too complicated design.
You waste alot of energy charging those capacitors with 2 PSUs.
You already have protection board on them, so why not just charge them at the nominal current?
He wants to charge them quickly, they're caps so can be charged at a huge current, that's whole point of him using them.
@Steve Cooper - That's right. Also, supercaps have poor energy retention, so the pack will always be discharged when you come to use it. A 2 or 3 minute charge time would be about right.
That's the whole point Julian takes a simple project complicates it as much as possible with as much hardware he can fit on his bench then spends a few videos troubleshooting looking for a solution, he reminds me of my local council highways dept makes you travel a long convoluted journey but not achieve any distance, very entertaining and colourful but pointless. here;s a quick fix stick a battery on it.
@@surfaceten510n and then we get to enjoy these videos!
@@surfaceten510n Julian should work in the electronics department at a German Auto maker. Wonder´if any of them are looking for any Over-Engineers at the time. LOL
Genius, a shed per project !
I can't be that extravagant - maybe 2 projects per module :)
One PSU connected to supercap bank via a mosfet, controlled by an Arduino connected to balancer LEDs, with a baby 128x32 OLED to show balancer and supercap state. Problem solved, visually appealing and more informative. If you want to get fancy, you could probably use three P&N Si4599 mosfets to charge the individual super-caps directly in sequence, since you can cut both the positive AND negative connections to each? 6A rated, so 2-3A should be just the ticket! :)
The DP30V5A DC power supply voltage & current regulator would do the same thing for you all in one. You just dial in your voltage and current, when it reaches what you have chosen, it will trickle charge or shut off. But I think you're just having fun with modules! :-)
This really does seem like using a wrecking ball suspended from a crane, to knock over a domino.
Can you explain why you’ve decided on such a complex charger when as far as I can tell, a single voltage and current limited supply would be fine, as long as the limits are set correctly.
Wrecking ball / domino - that would be 17 power supplies ;)
I want to charge the caps at a high current (let's say 10A) then wind that back to 0.5 amps when the first capacitor hits top.
Julian Ilett Yeah true, although maybe you could use 17 supplies, in 100mA increments 😂
Wouldn’t a typical buck / boost supply achieve the same result of high current charging and low current ‘topping off’? As the voltage rises, the current would naturally fall, and once it hits voltage limit, it would drop substantially.
Personally when I wanted to charge a large super cap bank, i used a typical lab bench supply with appropriate voltage and current limits and had no issues with overcharging, I however didn’t have the ‘current shuffle’ boards
A CC/CV power supply can only respond to the overall supercap 'pack' voltage. I want a PSU that responds when any individual capacitor reaches top, and winds the current down substantially and instantly.
@@JulianIlett If you used an isolated CC/CV supply for each supercap you could get more optimal charging.
A rolledup tube of cardboard around the red led and a photocoupler or light sensing transistor in the other end of the tube facing the red led should allow switching when the red led turns on.
I was thinking you could use a relay to swich between PSU's when the OPTO's are active. Powering it from the PSU input. Just a thought.
I found this video very insight full i just have a burning quetion.
Since the Converters are connected in parrallel why is the current not summend on output?
Would this not be a good use case for some "Ideal diodes" sure I remember them from a post bag a while back? Also have an alteria motive as just ordered some as want to experiment with a DC backup power supply. With solar 12V+ and a back ac2dc set just under 12v for if solar voltage drops. And Ideal diodes if they work
You ar so very awesome youtuber
Well, thank you :)
Why not have an arduino control a bjt which adds a second shunt resistor to increase the current of a single supply. When the balance voltage is reached is open the bjt and the shunt is returned to normal
For charging I'd be likely to just use a high current-limited power supply at "VPack-.2" and a low current-limited power supply at "VPack"
They would both charge when "
How about single power supply with two different resistors in place of the variable one switched by an arduino? Or one of those arduino controlled variable resistors? (X9C103S)
I would just use single charger and change the resistor values when switching the charging mode.
That's what I would do. Using an arduino mini with the gpio's connected to where he has the red led's, to tell when to switch to low current mode. Of course you probably could just use transistors to get the same result.
That's what everyone would do... except me :)
@@ianhaylock7409 Yep, no need for microcontroller, I think it could be made to work with couple optoisolators and resistors, maybe a transistor or two.
You could create a circuit that would utilize the opto isolator to adjust your output amperage on one power supply by adding or removing a resistor to the adjustment pot.
Either two Schottky diodes (with drop compensation) OR putting a, possibly opto-isolator driven, switch to toggle between the supplies so that when any lights come on they trigger the switch to kick over to the 0.5A supply while turning off the high-current unit would do the job I think. The diodes would be far easier, but the switch would be dumb fun and a more fun solution.
Why don't you connect 8 volts across the protection devices and let them do what they are designed to do? Perhaps using simple precision resistors instead of a catch 22 balancing circuit might require less complications.
How do I apply for a job for Ilett Corp when you take over the world with your supercapacitors?
In all seriousness, I've learned so much watching you and Big Clive these last few years. You both have really done a great job explaining electronics so it's easy for people to understand. Things have clicked for me and linked things I learned in elementary school with how companies implement things in products and all their electrical circuits work together.
Or put a Schottky diode in series with the opto to raise its voltage to match the red Led. Will add about 0.2v which might be enough to match the red with the opto's infra red.
Oh, that's a good idea. Yes, that could work. Cheers Mark :)
Just a low value resistor in series with the opto should do the trick
Wouldn't a constant current constant voltage charger do the same thing?
You just set to the voltage you want & max amperage you want. It charges at that Max setting. Then like a lithium ion battery charger, when it reaches full ( whatever you have set as max) it will trickle charge after that & just maintain.
Project finished? What about a case!?
Decking timber, of course :)
Make video on two same buck converter in parallel can they work together? If not what is the solution?
Can you put two solar inverters in series to double input voltage Vco solar panels
Wouldn't it be easier to use some combination of resistors and/or transistors connected to the LED signal from the capacitor bank to change the current setting on the PSU, so you can use one power supply instead of two? Haven't thought this through or finished the video so I may be completely off, but it seems like a nicer solution in my head
What are the buck boost converters in the video?
You should get those cheap LED volt amp displays for each PS so you can see everything all at once.
Will do :)
Utilizing 12 volt input on a 24v solar panel (Vco)
I like thinkering like that but why You can't set highamp psu set with voltage just bellow max voltage caps can handle. It will go down with amps anyway and then the lowamp psu will take the load. I understand that this is safety with opto idea but there will not be so much diference in voltage betwen caps like You created with shorted one in normal use. If there will be that diference then it is something wrong. At least it is my understanding
to me it's logical that the one goes negative which is set lower and the higher set module get even higher because you can't current share the way you want, when you want to do current sharing you have to set both modules to the same current otherwise you aren't doing any current sharing. You wanted to have the higher set module to do the first step then the lower set module kick in when the first module stops, the only way to make that possible is to control the modules separately via relais to isolate the two.
It's either one or the other, you can't do the two at the same time, it will never work.
is it possible to control those converters using arduino or stm32
It seems a bit over complicated and extremely unfinished...deja vu?
Have you done a load test to find out how long it will run the speaker?
Not yet - that will be a very interesting test :)
My guess would be a very interesting but very short video ⚡🔊😁👌.... ⏱️🔇🤬👎
Q=CV. Energy in Joules (Watt seconds) = 700F x (20V-6V). About 10,000 Watt seconds. That's 10W for 1,000 seconds (about 16 minutes).
That's not too bad actually, especially as it will probably average out at a lot less as most speakers are rated at PMPO rather than RMS output,
My guess is that it will use around 5 to 7 Watts before you hit distortion, so you may find that it will run for around 25 mins or so,
Coupled with a very fast recharge time that's really not too bad, I was expecting 5 minutes or so to be honest
You need diodes on output of PSU's preventing Back feeding between the PSU's ! Again use a Shunt connected to each PSU to better allow them to share loads. The Shunt works to steer the current more towards the load.
most psus have them integrated
@@drkastenbrot It is a more or less inherent part of every switch mode power supply. This one however is special, because it is everything but a simple step down or step up converter. See the datasheet for details: www.analog.com/media/en/technical-documentation/data-sheets/LTC3780.pdf Bear in mind that FETs do have a body diode that may become conductive unter certain situations.
@@drkastenbrot Not these chines toys. Well most don't. Some they actually tell you to install one. If the PSU looses it's source they back feed from the battery and go to PSU heaven.
@@blubbspinat9363 I played with these for a Wind Turbine set up. Wish I could find one better then just 3-5A. That's how I learned about the Shunt Trick. They will back feed without the diode across from each other if the drain or load is disconnected from them charging. They shouldn't because the load is gone and you would think they would stop supplying current. Guess they see each other as the load.. Not quite sure how the Shunt works with the sharing but it does. You can get two parallel units to track each other quite well.
Confused here. Why are you doing this ? The PSU will end charge when your set voltage is reached. If you have the PSU set for 2.7v per cap it won't go any higher. You have a Balance system in place.
The really cool way to fast charge a capacitor bank, in my opinion, would be to do the fast part from an even bigger capacitor bank, bypassing all the electronics, because you could do a large part of the charging in a couple of seconds, without any risk if you parallell every "step" like the active balancers are connected here.
The chargers capacitor bank could then just have nice careful charging always connected, that will keep it charged, and could charge the speakers capacitor bank the last part more carefully if it is just left charging.
Crazy expensive, I know, to have 2 or more times the speakers capacitor capacity in the charger also. But lets be honest, if this was for practical purposes, in order to be able to charge fast, you could've used a power bank that can take quick charge. That way you could get more powerful charging, than those
Don't forget the giant knife switch from which a huge shower of sparks rains down onto the floor :)
@@JulianIlett That has to be a bonus for a youtuber :) No, seriously, I was counting on wiring giving a bit of resistance, and even supercaps can't dump all their energy absolutely instantly, and having voltage difference of just up to 2.5V seemed unlikely to me be able to create any huge shows, or significant safety issues. If I'm wrong a video correcting me should be a popular video.
Julian, I think you were waiting for that question:
How did you got RYOBI mulimeters? ;))
I was surprised, i wasn't aware they made any.
They're quite old :)
I'm surprised. Are they any good?
(I am not going to by it, i have my own ones:) )
couldnt you use a PIC or arduino to vary the current on one of those boost/buck boards? when it senses a certain voltage adjust the current accordingly. you could have multi stepped charging that way.
Im not really sure how to vary the restistance on the charging board to change the current value though. maybe a relay and the NC output of the relay could have a resistor that sets it to 2 amps then when it hits a certain voltage activate the relay that has another value resistor to limit the current to 0.5A on the NO side.
I love these kinds of projects!
you would have to unsolder the POT from the boost/buck board also i guess.**
I was thinking Arduino or PIC when the project stalled - This PSU switching idea doesn't need any coding :)
@@JulianIlett Yeah, i commented before i watched the whole video. :) i got to thinking about ways to just use 1 boost/buck board.
How to use three meters and a bank of caps to do pointless things and consume 30 mins of your life!!
Oh but what a blissful 30 minutes it was :)
Why not connecting the caps in parallel and use a boost converter for obtaining the required voltage? This will make far more easy to charge it.
Not many boost converters work down to 2.5V on their input. To extract a useful amount of energy from the capacitors, the system would have to keep working down to 1V or so per capacitor.
@@JulianIlett You could charge in parallel and switch to a series configuration to discharge. I like Alejandro's idea of charging in parallel.
Screw the components down on the deck boards. Like bread boards.
Why so complicated ? Use one of the buck/ boost to CV/CC ? 7.5 V ? Zeners on the Caps ?
Won't work - the first capacitor to hit top would go way over voltage.
Can we dump 5 kw in SuperCapacitor bank in 30 sec it's possible or not??
Opto reciever :)
Watch out for imposed HF on your power from SMPS, it's a killer in audio..
How much current will go through those blue LEDs when they're on?
I'm guessing a few milliamps
Julian Ilett because the super cap voltage is too low to fully switch them on?
Julian Ilett Can only find one diode? I expected more of you Julian. lol
Julian designs way too complicated circuit. Everyone else buys off the shelf product.
Whereas I buy product and put it on shelf :)