Cap Dump Circuit

[vidbid]

Hello group

Here is a video of my progress and how I can run over 500 watts of surging power into batteries.

https://www.youtube.com/edit?video_id=tAflPiIM1gc

Mike A special thanks to all my helpers.

Hi Mike,

Interesting video at

Capacitor Discharging RC source - YouTube

Regards,

VIDBID

[BroMikey]

Capacitor discharging operation

Hi Mike,

Interesting video at

Capacitor Discharging RC source - YouTube

Regards,

VIDBID

Thanks VIDBID

I also need to add one more thing about my specific circuit. These machines are called "ENERGY PUMPS" I noted that if I put an amp meter between the charging batteries I can see amp surges this way.

The thing is that when experimenters make pulsating circuits the fear is that they will lock up their devices (In this case Mosfet's) and burn them out, so as I adjust my pulse circuit to a shorter time down to zero I was afraid that they might not oscillate, right?

Well as it turns out with my diagram even when I turn the time for a pulse to nothing the LED still flickers and the fets still open and the circuit still surges a 20-30amp pulse or some say a 100-300 amp pulse measured in a very short time.

I know this, when I dump that bank with a single discharge it acts similar to a welder at 50-70vdc. Screw driver tips vaporize in a blink.

I have been burning my circuit in and have reached 5-600 watts with little heat. I don't know how to relate the power and potential effects of a large discharge at 500 watts.

One discharge behind the other? Faster and Faster with an ever increasing flow of surging amperage til the source is still fluctuating, but higher.

For example if I run low power and a slow pulse time the amps will charge the cap bank coming up to say 1 amp and then back to zero. However as I increase the speed of the dump, the RC charge curve will require a higher cap bank voltage to deliver the same voltage dump to the batteries.

As I go faster and more voltage, the power levels climb and so far the highest that I have sustained for a single 120vac wall plug without flickering the lights is 900watts. The circuits are not getting hot at all.

I like the extra power that general I won't be using all of the time. The critical factor is the RC charge curve for filling a large bank of caps without throwing the mains on your house when power levels are elevated.

200-300 watts is nothing to a 1500watt wall plug so there will be no problem at those levels even with a messed up design.

Try getting up near 1000 watts sometime of pulsating power and you will see my dilemma.

At first try I found that even a 1 amp input of unregulated power to a discharging cap bank could nearly pin the needle to 15 amp surge demands between dumps for charge up.

Now I will say that the SG Oscillator is a great tool and can improve the efficiency of dumping operations. Many of the guys here have pointed out that when dumping caps it is better to turn the supply OFF for a short duration so as not to interrupt dumping functions.

The Sg oscillator does that and the inventor made these to work together in his patents.

The SG Oscillator can be a solid state circuit as mine has always been and it performs this operation nicely. The SG Oscillator has several modes that it can operate in and when it is connected to a cap discharging bank will be far less disruptive to the dump circuits than wall power.

This compatibility of Oscillator connected to cap dumping circuits was designed by the inventor over years with exhaustive testing.

I can say now that the SG Oscillator is a great tool and as it supplies the cap bank with voltage for this type of radiant pulsating DC, charges caps, and will condition caps to except a charge faster and this increases efficiencies of the design.

I designed my block transformer supply and resistor to have an alternative means of powering my dumps off of a Genset running in the yard when the power fails.

I spent one full week without power a couple of years ago and I promised myself I would be ready this next time the high winds came.

Every year the power goes out here even if it is only 8 hrs.

Some are using Oscillators or inverters as they are called without much of a coil of wire to power a cap dump.

In my case I am building an inverter Oscillator combination switchable from spike mode to Genmode to rene mode.

It is coming.

If you look at my last video I show this hardware right at the very beginning.

It is another circuit just like this cap dump circuit, exactly. The only

difference is the rate of oscillations is 8000-17,000HZ instead of 3-5hz.

Mike

[BroMikey]

Cap Circuit figures

Okay I am learning to look at the HP54100 scope and I was seeing the 55 timer at 500ms(miliseconds)

Now I see the switch but why do I get -.

Most of the adjustments put me from 50ns to 400ns to 10us

Sometimes I get rise times in the negative.

Like (-140ns) rise time and 50ns fall time

I am not sure what this means.

My battery is set and on a pallet, lead bus bars and 150amp wire 30ft long from the basement to the 2nd floor.

The dump works great.

If any of you can answer that question I would be open to hear it. I am learning about scopes.

Michael

[BroMikey]

Scope Work and Minus Signs

If any of you understand the minus sign on oscilloscope screens let me know.

I am testing the rise time on the switching of a mosfet IRFP250 and fall time and the scale is NANO or ns this is nano-seconds.

As I adjust my switch driver I can control time and duty where sometimes I read a minus or this sign (-) in front of the number like say -140ns.

My question is what does the minus sign show? Then I will adjust and the value will move as expected to say 50ns.

I realize that this is a highly technical question that all you theoretical Physicists won't be able to comprehend, so I am looking for a hands on guys who can build something and is able to operate an oscilloscope.

Thanks in advance.

Michael (I will continue to ask this question)

[BroMikey]

Running up Power

Was running up the power and adjusting the frec and duty and noticing how the rise times and fall times would flip over and I would lose one fet each time. This 555 timer to opto popped or I saw a flash and it sounded like a fire cracker went off.

What happened was my heat sink was hot all day because we went from 40 outside to 90 degrees in one day, the fets were not tight on the sink I should have re-tightened them after a short heat up, to much heat-sink grease and heat, makes for loose parts in a jiffy.

Besides cold solder joints and sinking problems my steering wheel (a weak example of a triggering circuit) being a 555 timer to opto.

It seems you all were right that it would fail.

Well you didn't all say that, you just said "I WOULD DO IT THIS WAY" and so on.

Now I can see why.

The 555 timer triggers an opto and this fires a transistor.

I am and was getting negative and positive triggering all in the same breath.

I tee total mess of conflicting triggers.

My scope would say -140ns rise time and 40ns fall and then if I adjusted the 10 turn pots on the fly the pulses would swing wildly.

You know 500ns rise and 200ns fall and then sometimes I could get it down to 10ns rise and 10ns fall but the problem is when you adjust on the fly if a bad spot develops on your wiper of your pot erratic triggering could blow things up and did several times.

I have the drivers and tl595's and am redesigning. The heat sink is done as of today. I built a new sink that resembles the wheat-field sink. Or whatever that name is.

Bee C-in Yons

Mike

[BroMikey]

Mosfet Driving Types

Hello Group Members

I have been doing some reading on mosfet drivers and considering all of the words and examples each of you has given me.

What I have found is that low power and high power drivers can do many things but because I do not need multiple functions occurring I will stick to the simple non-inverting high power drivers.

Also according to the big semiconductor companies anything operating at 80v and above use Mosfets that are 500v devices not 200volt devices like I have been instructed to use.

Of course these companies want to sell parts and their rating is for industrial uses.

Although I was having the same burnouts at low voltages.



You will note that to properly drive a Mosfet for high power applications and for highly accurate digital processing that pnp and npn transistors are employed.

Many experimenters use a single 555 timer and caps, resistors with low tolerances so at higher powers this is like a gate swinging wildly.


I could measure -150ns rise and 400ns rise with only 1/16" turn on the dial and crash all of my parts in a short time.

I was using an opto to a single transistor and very sloppy work.

The driver can be properly done without a packaged part as well.

Michael

[BroMikey]

No Driver Circuits

Here are a few examples of what can be found all over the web that are good for 5-25 watts. Very low powered. Led lights and blinkers.

no driver.JPG

no driver2.JPG

Also here are some circuits that are all grown up and qualify for handling higher power with longevity in mind.



In the bottom picture this man was able to drive 4 Mosfets using his own driver with the PNP and NPN toggling like found in prepackaged drivers.

My circuit needs to handle 80vdc at 10amps. 800watt power circuits are far more involved if they are to last.

Industrial apps say that any device operating at 80v and above should be designed using 500v ceiling devices and at present all I see experimenters using are the 200v devices.

So what I have decided is that since my circuits keep burning out i will use 12 mosfets and another more advanced circuit for controlling them.

I will show a picture of my home made heat sink with devices soon. The fan and 4 devices are installed already.

Mike

[Mario]

Hi Mike,

If you follow the SOA curve of your devices you should not burn them.

I already wrote this, but if you use an opto the best rise/fall times you will be able to see on your Fets is 4-5 microseconds (not nano). It's simply not possible to go faster because it's the limit of your opto (h11d1).
Only using a driver you will be able to switch faster. So I don't know how you're able to see nanosecond switching if you're using an opto.

One reason for toasting fets can also be this:

When you turn the dump OFF very sharply (talking nanoseconds) and you are not dumping down to the battery voltage (even just 20 or 30V above the battery) you will get a negative spike that can be even a few hundred volts in amplitude. It's like your battery is behaving like a coil, you pulse it, and when you let go you get the flyback spike. This is why it's important to watch the dump pulse on a scope and learn all about it while you change parameters and see what happens.

regards,
Mario

[BroMikey]

Getting smarter

Hi Mike,

If you follow the SOA curve of your devices you should not burn them.

I already wrote this, but if you use an opto the best rise/fall times you will be able to see on your Fets is 4-5 microseconds (not nano). It's simply not possible to go faster because it's the limit of your opto (h11d1).
Only using a driver you will be able to switch faster. So I don't know how you're able to see nanosecond switching if you're using an opto.

One reason for toasting fets can also be this:

When you turn the dump OFF very sharply (talking nanoseconds) and you are not dumping down to the battery voltage (even just 20 or 30V above the battery) you will get a negative spike that can be even a few hundred volts in amplitude. It's like your battery is behaving like a coil, you pulse it, and when you let go you get the flyback spike. This is why it's important to watch the dump pulse on a scope and learn all about it while you change parameters and see what happens.

regards,
Mario

Hey Mario
Thanks for the info on back spikes, I had not heard this. However when I first built cap dumps I used 600 v 2sd2499 transistors and still have these units.

I just ordered some 500v IRFP460's for the same dang money as those 200v devices. What a mess of diagrams pasted all over the web

You were right I am looking at the SOA now and unless I am very very careful not to go out of the marked areas I can kiss my fet's bye bye.

The reason I decided to use the 460's is because they are in a standard switching PC supply that operates on a voltages from the line of 120vac, so I figure these parts are rated about where I am running.

See I want to hit 36volt batteries with 90-110 volts DC and like you say with all of the back spikes and then the possible failure on my part to go to high on the duty cycle, I am needing to rethink.

Okay here is what I want. I want a box that you can adjust all around a given set parameter , running up power to 70 percent duty and have the device run cool and never blink.

You said it right in the beginning, you told me to see if my parts can handle this and they can not. A IRFP250N and the 260 break at 200volts.

Then the opto's being slow and sometimes fall times are cut short by me and flash all my parts,humm...

Got the tc4420's and the pile of 594's and need to zero my tantalum caps and high tolerance resistors plus poly caps and will be ready to make something realistic.

I think the way i am playing with times and duty cutting off that it is important that I not run the fine line using these 200v devices.

I have had one dump that can not fail using 600v devices. I use overkill. I used 5 devices 2sd2499 never once had any problems. I didn't even use a fan and let them get hot. Still working great. I use a fan now because it works better.

I see the SOA and a 200v device like they are stop at 50vdc for decent amp usage. The industrial guide at the big semiconductor companies say that for 80v operation and above use 500v devices if you want a box that goes 20years, not 20 minutes like my units last. Now i see why.

I am still going to do it using these under rated stamps, got a bank on already and still drilling the holes and tapping.

Okay the scope is showing 300ns and 500ns and sometimes way less but it is erratic. i think you are right about opto's being a bad choice for gates on a Mosfet. Door bells work fine but this device is running power.

The stuff on the web for beginners is there to make it simple to build and if you want something better you will either need to go to someone who knows how to do it right or learn yourself.

I see opto's used in high speed switching but I don't know how fast the app is, maybe certain set oscillations up in the frec's can settle for 100us.

Can't wait to try this new circuit out. With 12 devices i should do better since the 6 I had didn't. But who knows maybe they just can't handle 80vdc with all of the inrush and back spiking.

75 percent duty is an abuse that these circuits should be able to take or they are under rated in my opinion.

I will have another box that you can beat and it never fails.

This is my goal. Not some cheap version of a device bordering on disaster.

Like you pointed out Mario back spiking and the with the SOA curve hardly anyone is building using and showing the application of an industrial level circuit. Mostly little cheapO timers to a fet and wow wee we are all supos-ta be in heaven cause were are pulsing a battery.

I need more than these toy circuits and thanks to you and few others I am on the right track and I will look at my scope close.

Mike

[BroMikey]

Diode

Here is a diagram of what a friend used when he built a driver for 250n Mosfets that power a coil.




Mosdrv.JPG


I am wondering if these diodes protect the mosfet from spiking? If anyone knows the answer please let me know. The diode number is HFA08TA60CPBF Diode Hexfred 600V

https://www.youtube.com/watch?v=rtsuxU2VxOU

In this video we see mosfets of low power being over driven to a potential 300volt reverse spiking. People seem to over look ratings. a 200volt fet is best suited to work at 50-60 volts under heavy motoring loads.

Mike

[BroMikey]

Mosfet Failure Study

This information is for those who are not engineers yet are electronic masters.

These links help me to refresh why my mosfet's got smoked and how to select the right value. In one of these videos the man shows the difference in spikes from load to load.

If you have an inductor or a battery power can be stored and the reflective reverse polarity kick back will burn out you Fet if the break down voltage is incorrectly used.

For instance in my case I do not want to stop the ringing in my cap dump circuit so when spiking occurs with every pulse a snubber is not used.

Therefore a higher voltage mosfet must be selected than normal electronics would prefer. As an example I have been burning out Mosfet's all week wondering why. The pulsed voltage to an energy storing device in this case a battery was 80vdc and the Mosfet I thought being 200vdc would be plenty.

As it turns out many of the fictitious circuits planted all over the web offer ill advice while lots of other give excellent designs.

My working cap dumps use 500vdc Fets while the 200vdc fet all burnout when pulsed at 80 volts.

If you did not know spiking often generates reverse voltages of three times that of what the power supply if providing.

So remember that there are alot of nice people who are designers on the web who make circuits on paper but never test them in real practices and therefore their circuits must fail.

Just a few basic designer fact can actual weed out which circuits are good ones and which ones may work for awhile but are destined to fail.

Part of the problem with design models and company marketing trade offs is that the sellers have trained all of our engineers to drive a heavy load with as few parts as possible driving down production costs and thereby increasing corporate revenue.

These devices have a shorter lifespan than what I am after and this is why I have chosen to take a look at the industrial design topologies.

Many poorly designed electronic devices exist on the market today for the average residential costumer and are often products that are used only occasionally or intermittently.

With industrial power controls and device a 100 percent duty cycle is more often than not a requirement so entirely opposite approach is taken when circuits are engineered. Or should be.


Don't take any wooden nickles "that's all I am saying"

This "CAP DUMP CIRCUIT" discussion will end in a working circuit other than my beginners design from old scrap parts off of TV sets that are all functioning in the pink.

So far using mosfets rated at 200vdc in the way I want to use them only permit a pulsed voltage of 50-60 volts with spikes of 180vdc.

IRFP460 MOSFET is one answer as it has the right break down voltage rating(600vdc) for a pulsed voltage as high as 100vdc with 300vdc spikes. This 100 voltages dc is being pulsed to a 36vdc battery bank.

I my studies and experiments using inductive spiking and cap dump pulses to a battery I have discovered from John bedini that for a 12vdc battery I should and have pulsed 30-35vdc to it. Other batteries much large charged better at as high as 40vdc with pulses only 1 per second or less.

For a 36vdc bank this would result in a 120vdc pulse to the larger bank and is not to much to ask (Or shouldn't be) for a mosfet as my other transistor types are doing just fine with these voltages.

It's just the misinfo that ticks me off.

Time to study.

Inductive spiking tutorial - YouTube


Remember that you don't want to eliminate ringing in the battery so snubber circuits are out, snubber diodes or any ring canceling strategies.


Just simple simple turn on turn off figures on the data sheet so if a transistor is rated at 110 amps pulsed and it is the size a a split pea remember that these design criteria more often than not make no practical sense.

Just stick to common sense instead.

Practical MOSFET Tutorial #2 - N Channel, Low Side and the Body Diode - YouTube

Remember pulsed current and drain current are max values and some of that is measured in nano seconds of inrush current while the leg you are soldering to a circuit board is equivalent to a 16awg wire that can only handle 10 amps.

So figure 5 amps per mosfet MAX. If you need a 50amp handling capacity and you want to to last and run cool use 10 mosfets.

If you are driving an RC controlled airplane making it drain a battery in 10 minutes and you need to lite weight then use 2 Mosfets because these circuits are known for only intermittent use and fast burn out.

Not me I want my work to run cool. And when it is time to charge my bank of batteries I don't want to have to put in another row of fets every time like I have done now for the last month.

P-FET Reverse Voltage Polarity Protection Tutorial - YouTube


Preventing Reverse Polarity Damage With Simple Diode Circuits - YouTube

These are my personal views concerning circuit designs and when I am done here this mosfet pulsing circuit will out live me.

Mike

[JohnnBlade]

Greets Bro,

I like yr style, may i share something here?
Thnx


In my xp i found out that load must be connected to a cap that feeds something when not using it, otherwise it will surge true and burn transistors.

Sofare only my transistors burned all out cause of a surge, and its not the amps

Even if my transistor can handle a socalled 8 amps or 6 forex 2n3055

A voltage or a simple spike can fock it all up, so what i do now if my device is running i am transfering that load to somewhere else, and if i dont distribute that energy i use a dummy load to atleast keep my transistor calm that after loads any transistor.

Can i see some of yr art?


Greets JB

This information is for those who are not engineers yet are electronic masters.

These links help me to refresh why my mosfet's got smoked and how to select the right value. In one of these videos the man shows the difference in spikes from load to load.

If you have an inductor or a battery power can be stored and the reflective reverse polarity kick back will burn out you Fet if the break down voltage is incorrectly used.

For instance in my case I do not want to stop the ringing in my cap dump circuit so when spiking occurs with every pulse a snubber is not used.

Therefore a higher voltage mosfet must be selected than normal electronics would prefer. As an example I have been burning out Mosfet's all week wondering why. The pulsed voltage to an energy storing device in this case a battery was 80vdc and the Mosfet I thought being 200vdc would be plenty.

As it turns out many of the fictitious circuits planted all over the web offer ill advice while lots of other give excellent designs.

My working cap dumps use 500vdc Fets while the 200vdc fet all burnout when pulsed at 80 volts.

If you did not know spiking often generates reverse voltages of three times that of what the power supply if providing.

So remember that there are alot of nice people who are designers on the web who make circuits on paper but never test them in real practices and therefore their circuits must fail.

Just a few basic designer fact can actual weed out which circuits are good ones and which ones may work for awhile but are destined to fail.

Part of the problem with design models and company marketing trade offs is that the sellers have trained all of our engineers to drive a heavy load with as few parts as possible driving down production costs and thereby increasing corporate revenue.

These devices have a shorter lifespan than what I am after and this is why I have chosen to take a look at the industrial design topologies.

Many poorly designed electronic devices exist on the market today for the average residential costumer and are often products that are used only occasionally or intermittently.

With industrial power controls and device a 100 percent duty cycle is more often than not a requirement so entirely opposite approach is taken when circuits are engineered. Or should be.


Don't take any wooden nickles "that's all I am saying"

This "CAP DUMP CIRCUIT" discussion will end in a working circuit other than my beginners design from old scrap parts off of TV sets that are all functioning in the pink.

So far using mosfets rated at 200vdc in the way I want to use them only permit a pulsed voltage of 50-60 volts with spikes of 180vdc.

IRFP460 MOSFET is one answer as it has the right break down voltage rating for a pulsed voltage as high as 100 vdc. This 100 voltages dc is being pulsed to a 36vdc battery bank.

I my studies and experiments using inductive spiking and cap dump pulses to a battery I have discovered from John bedini that for a 12vdc battery I should and have pulsed 30-35vdc to it. Other batteries much large charged better at as high as 40vdc with pulses only 1 per second or less.

For a 36vdc bank this would result in a 120vdc pulse to the larger bank and is not to much to ask (Or shouldn't be) for a mosfet as my other transistor types are doing just fine with these voltages.

It's just the misinfo that ticks me off.

Time to study.

Inductive spiking tutorial - YouTube


Remember that you don't want to eliminate ringing in the battery so snubber circuits are out, snubber diodes or any ring canceling strategies.


Just simple simple turn on turn off figures on the data sheet so if a transistor is rated at 110 amps pulsed and it is the size a a split pea remember that these design criteria more often than not make no practical sense.

Just stick to common sense instead.

Practical MOSFET Tutorial #2 - N Channel, Low Side and the Body Diode - YouTube

Remember pulsed current and drain current are max values and some of that is measured in nano seconds of inrush current while the leg you are soldering to a circuit board is equivalent to a 16awg wire that can only handle 10 amps.

So figure 5 amps per mosfet MAX. If you need a 50amp handling capacity and you want to to last and run cool use 10 mosfets.

If you are driving an RC controlled airplane making it drain a battery in 10 minutes and you need to lite weight then use 2 Mosfets because these circuits are known for only intermittent use and fast burn out.

Not me I want my work to run cool. And when it is time to charge my bank of batteries I don't want to have to put in another row of fets every time like I have done now for the last month.

P-FET Reverse Voltage Polarity Protection Tutorial - YouTube


Preventing Reverse Polarity Damage With Simple Diode Circuits - YouTube

These are my personal views concerning circuit designs and when I am done here this mosfet pulsing circuit will out live me.

Mike

[BroMikey]

Cap steadying the transistor

Greets Bro,

I like yr style, may i share something here?
Thnx


In my xp i found out that load must be connected to a cap that feeds something when not using it, otherwise it will surge true and burn transistors.

Sofare only my transistors burned all out cause of a surge, and its not the amps

Even if my transistor can handle a socalled 8 amps or 6 forex 2n3055

A voltage or a simple spike can fock it all up, so what i do now if my device is running i am transfering that load to somewhere else, and if i dont distribute that energy i use a dummy load to atleast keep my transistor calm that after loads any transistor.

Can i see some of yr art?


Greets JB

Hey John

Good Idea here is my working circuit, not this mess I am making lately.

BroMikey's Science Projects look for BroMikeys dump

Another thing I must say is that a few years back I got word that MAYTAG lost their company because of Mosfet circuits.

I have done appliance repair 40 years. I rebuild digital circuits if need be.

The new generation of engineering squirts came into change the world with their 59 cent Mosfet to run 3 phase washer motors driven by inverter boards connected to the 120vac mains in our homes today.

Their circuits were and are so incapable of doing what they were designed to do that no one had one over 5 years without needing a replacement board costing 600-1000 dollars.

The inductive spikes coming back from the motor coils kill the fets and they were trying to pinch pennies ya know.

Well they put themselves out of a job and embarrassed the largest most reputable appliance company the world has every known up until that time. Whirlpool bought Maytag a few years ago only to resurrect it from the ashes.

Remember the NEPTUNE? The first front loader washers? Well this is where they failed all of their fets.

There is not a more powerful example in our day that shows the stupidity and arrogance of men and how they could be brainwashed so completely by our universities leaving them incapable of doing their jobs.

The whole electronics business/industry is bent on their own foolishness for money.

However there are still a few great men around in this field that know better than to be sucked into any new designs that abandon common sense.

These companies run the industrial show producing nearly indestructible equipment. Anymore the residential stuff is rated at 2000 watts can only run 400-500watts at a 30 percent duty cycle.

What a mess of red tape and lies when it comes to shifting numbers around.

I hate cheaply done electronics mainly because it stops working duh.

What do ya think boys? Hey John show me a shot of where to add my cap to steady the transistor.

Mike

[BroMikey]

Proper circuit 36vdc/90vdc Cap discharge

Here is a proper lay out of what a cap dump with it's ratings for Mosfet's should be.

PWMCirc2.jpg

This circuit can handle the reflected 3X spiking that can occur.

Mike

[Dave45]