An energy harvesting project

[JulesP]

Hi Rodolphe,

I think that as long as you have a stable and repeatable method then that will enable you to see changes in the battery response and hone in on the optimum PRF (and other variables) for your setup. Each battery appears to have a natural ringing frequency to the pulses.

I certainly found that the response can change more than 150% over a 15Hz range as the attached graph indicates. Normally you find a raised value in a frequency zone and then zoom in around that frequency. You can see from the manual the PRFs I found for a variety of batteries. But again, slight deviations in the methodology will introduce errors that can mask that fine-tuning and so being consistent is important.


Once you have the optimum values then you are getting the best from the battery when it comes to determining power outputs, which is the stage I’m at now.

Finding the power output for a cap dump and rotor is relatively straightforward (although two equally valid calculation methods give values different by a factor of 2 since one method is a dynamic one and the other a static one, so I’m investigating that) but for the receiving battery is rather more involved. Soon I will be writing a document outlining a method of deriving the battery CoP and passing around for comments.

As we have seen, CoP values based on elevated charging voltages do not relate to power output in a straightforward way so that stage should perhaps be conceived of as one to find the best battery response in preparation for real-time power output measurements and then related to power input values.

Also, I am beginning to see that the optimum charging, and for ‘radiant’ effects to manifest, is not just about the potential, as has been implied by various contributors in the past, but also requires a minimum amount of charge. That being so, your CoP measurements based on Ah (charge) may well be more indicative of available power than ones based upon potential alone.

Lastly, reconfiguring my system to be in the traditional SG mode is straightforward for the rotor system but not so when I add in my cap dump circuit. This is because I designed it as a high-sided one (switching the positive cap to the battery line instead of the negative) to go with my swapper. I am going to construct a low-sided version (a simpler circuit) so that I should be able to integrate it with SG mode (no swapping) and see how it performs.

I guess one day I will come up with an answer to my original research question and how to achieve it.

J

[pearldragon]

Hi Julian,

Thanks for all your answers.

To start with the last part since it is most crucial in my tests for now:

I deviated slightly from my previous method in the sense that before I took manual readings and used for my Ah calculation my manually noted down amp reading at 60% of the charging time.
That process I automated now by using the digital multimeter, taking automated measurements every 5min. Although I still use the 60% reading (to compare with my previous measurements) I also now have a new measurement method, by taking the average of the readings during a charge cycle. In other words:

Old method:
-take amp reading @ 60% of charging time
-with the above mentioned amp reading and the total time it took to charge I calculate how much Ah is supplied by the Power unit (PSU) as input
-With this Ah value and knowing that I discharged 1Ah originally out of the output battery, I can calculate my COP.

New method:
-auto record amp values every 5 min, at the end of the cycle add all the values together and divide them by the total number of recordings
-with the above mentioned amp reading and the total time it took to charge calculate how much Ah is supplied by the Power unit (PSU) as input
-With this Ah value and knowing that I discharged 1Ah originally out of the output battery, I can calculate my COP.

Calculating it in J would in relative sense will not make much of a difference:
For charging, the input the PSU delivers constant 12V, the amperage draw and time (based on my measurements) are also fairly constant. Same goes for discharging: amperage draw is constant 1A, time is constant, average voltage would only change very minimal.

With all the measurement I’ve done so far, the difference in COP is all within 5%. My plan was to go to more accurate measurements once I see a change in COP, but since it is all in the range of 40-ish% a necessary increase of more than x2 will show up very clearly also in my inaccurate way of measuring.

I scanned the following frequencies: 40Hz (testing while writing this), 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, 100Hz, 110Hz, 120Hz, 125Hz, 130Hz, 140Hz, 150Hz, 160Hz.
Around 100Hz it seemed a little bit higher, so will go there in the steps in between next week probably (e.g. 105Hz, 115Hz), but I don’t expect to see a huge jump suddenly.

Other settings:
-Duty cycle 50%
-Active device STP20N95K5
-Welding rods as Core material
-12V input voltage (PSU)

I still plan to do a quick test with only 1 coil connected, with very short connection wires and the ferrite as core material, to see if scope reading of the HV pulses will become similar to yours.

Output battery that I use:
VMF - 52805 12N24, 24Ah 293A(EN), Flooded lead acid.

CBA that I use is a CBA V (West Mountain Radio), I have a IV as well.

If you think I’m missing something, or should focus on something else first instead of the frequency, I’d be very keen to hear. Otherwise I’ll continue as mentioned: scan some frequencies around 105Hz, 115Hz, and might consider going further down, 30% (depending hoe current test turns out) and maybe further up 170Hz, 180Hz.

After that I might try another battery.

Best regards,
Rodolphe

[JulesP]

Hi Rodolphe,

Re 90: Your spikes seemed to have a distinct curve at the bottom which may be due to capacitance of some sort but also, as I suggested, due to the time base setting that spaces the spikes out. I attach one of mine for comparison. Any difference may have no significance but it could be due to my using ferrite cores and not R45. Stronger mag field and probably less hysteresis so sharper cut off.

Re 90: The reason my design has a common earth is because of the swapper so that the positive line can be swapped as the supply without having to also flip the negative. With a common ground line the obvious place for the main switch, fuses, and meters is in that line otherwise you would have to change the contacts for measurement every time the swapper operated. In terms of measurements, having the meters in either line makes no difference, so I could have had a common positive and switched the negative. However, since many other parts of the circuit need to link to a common line and it is 'tradition' to link the negative ground lines together, then that is the route I have taken. When it comes to measuring the current, since I was staying with Battery 1/PSU as the supply (so swapper off), then for the measurements I could just insert it as close as possible to the source in the distinct line i.e. the positive. Also, since I would often get slightly larger readings when my meter was placed near the main switch and fuses, I got the impression that it was not the best place to put a meter (ok for the inaccurate panel meters) so for accurate measurements, like in CoP tests, I opted for the positive line close to the supply as you are doing.

Re 92: I have tried a 4.5kV device but I need to modify my divider to a 20:1 arrangement as the limit on my scope is 400V. Also, since my scope has died after 5 years and another is soon to arrive, I will soon be able to measure the spike output with this IGBT (IXYH30N450HV - expensive but the best value was Mouser). An added complication is that the leg format is different from the 1.7kV device and so I have had to use some wires that cross over the solder points. Whenever I get around to updating the PCB I will include a site for the TO-247HV format as well as the other two: TO-247 and TO-220 as well as isolate the collectors/Drains so that all three devices can be installed at once without burning each other out. In due course, I will see the effect of these higher voltages as part of my larger bank of power tests, as indicated below.

Re 94: The only reason why I was considering going 'backwards' to build a single or seven coil SG machine was in the hope of observing 'radiant effects' as per the SG-1/2/3 manuals and then cross-reference to my system to see what features are important. Now that I am getting some promising power data I no longer need to do that but am focused on adapting my system to be able to switch between my current 'common ground' configuration and the 'Classic SG' and the Genertor' modes. I have plenty of testing planned with all these modes and using the rotor, cap dump, pulse combing and straight HV, and with up to 4.5kV, or as high as my system will go with that IGBT.

The reason I suggested using my PCBv4 as the power supply is that it is already there doing that (via the swapper relays, Buck/Boost converters etc) so there was no point in removing it and leaving a big hole and having to fill it with something doing essentially the same.

Re your progress: If you like I can post here or send you a precise methodology for you to try that I used for my voltage-based CoP tests. Once you have a standardized method then it makes comparisons more appropriate. If you are using Ah(charge) for your measurements, instead of energy (Wh=J) then that may give quite different results. What battery and CBA are you using?

Kind regards,

Jullian

[pearldragon]

Hi Julian,
Had some time to kill on a train ride yesterday and made the most out of it :

Post #83 - max charging voltage with regular charger:
The voltage where the charging curve became horizontal kept on rising with every charge/discharge cycle I did with the regular charger. Once it hit +/-14.26V the battery charger did stop charging (instead of continuing after 10+hours).

Post #90 – Slow switch off of active device
You said “Your spike voltages are good for the device used (IRF840) although seem to be switching off slower, hence the curved slopes.” When you say “slower” do you mean slower than the spike rises (switches on)? Or did you mean slower than that your IRF840 switches off? If the latter is the case, any idea what might be the cause of this? In the measurements my coils had less inductance than you, so if I expect to see anything, I’d expect them to switch off quicker (unless the inductance is not the cause of the slow switch off). My measurements on the scope for the STP20N95K5 and STP12N120K5 look the same, so the IRF840 itself was not the cause.

Post #90 – Amp meter
“PS. Please note that my inserting the ammeter into the negative line via the plug panel is not in fact the best place for it to get an accurate reading. I found that going from the supply battery directly to the meter and then out to the negative line was best. I can give more info on that if you need. Of course, with battery swapping, you can't really use a digital meter since when the meter is in battery line during the charging stage, it won't like the spikes and may damage it so I used the configuration shown with swapping off for the CoP tests, and also similarly when substituting the supply battery with a PSU.”
The panel meters I have installed as show on the diagram (so in the central negative line), but the digital multi meter (DMM) (that I finally started to use ), I connect directly to in the positive line from the PSU, and then from the DMM to the machine. Any particular reason why you choose the negative line? On my Bedini SG I experimented with a fairly accurate Analog meter in the negative and the positive line, but for me it did not make a difference.

Post #92 – Paul B Voltages
“It is possible then that at the voltages that Babcock uses to go beyond the 'ether tidal region' as he describes it.”
Have you tried to go to these voltages? (don’t know out of the top of my head what they were)

Post #92 – Impedance
“…impedance is the major blocking factor and where it matters most”
Also here; With my SG I went pretty extreme with replacing all cables to something like AWG 10 or 8, but for me it made no difference at all. It could be however, that it only starts to make difference if your machine is producing some over unity already, in other words; when your pulsing at the right frequency… My very limited adjustability of the frequency/RPM of my SG might have been the first bottle neck so I could not notice (yet) the difference that the thicker cables made.

Post #94 – SG setup
There are still a couple of things that are unclear to me regarding your next step going to a SG setup:
-“..monopole design and seeing how any radiant effects manifest before…” Which things would you be able to see/study with the SG setup, that you cannot with your current Solid State design (SSD)? The whole reason for me that I moved to your SSD is that I did not have enough control over certain parameters, that the SG has not, or at least not in an easy way…
-“ The present PCB v4 that you are using can be used just to manage the supply from a PSU, so standing in for a supply battery.” Why would you need your PCB for this? -> Why would you not be able to connect it directly to the input on your proposed new PCB?
-In case it helps -> I probably still have an unused 8 transistor PCB board from TeslaGenX for the SG lying around here… But with the customization you want to do, it is probably of no help.
-Some suggestions/additions for your prototype new PCB:
--have the option of adding more (Transistors) coils in parallel
--have the option of adding more D1 diodes in series
--have the option to switch to Common ground/generator mode
--Maybe you want to swap out your diodes for different version (UF / or silicon carbide versions) and make a feature for that. But if you don’t mind soldering them in/out, that it is not necessary of course.

Progress on my tests
I did runs @ 100Hz, 110Hz, 120Hz, 130Hz, 140Hz, 150Hz, 160Hz, but did not notice a mention worthy change in COP. Will continue up till 200Hz, and then scan the a bit in the lower ranges (90Hz 80Hz 70Hz 60Hz, after that continue above 200Hz, or go in the steps between; 105Hz, 115Hz, 125Hz, 135Hz, etc.
All done so far at 50%duty cycle, welding rods as core, majority done with STP20N95K5.

Best regards,
Rodolphe

[JulesP]

Hi Rodolphe,

You have explained the different spike voltage which all makes sense. There will be some temp variation but a few hundred volts is hard to explain based on temp alone.

Re swapping, I have used 3 min and 10min swapping with both HV spikes and cap dump discharges. I'm aware of the idea that swapping to a 'blue' battery (radiantly charged) for a supply can damage the circuit, which is part of the reason why JB proposed the cap dump system, as that converts the spikes to conventional charge.

By SG I mean returning to the original patent-based monopole design and seeing how any radiant effects manifest before then working back up by modifying one thing at a time. I can use my rotor system by adapting it for this and then put the 'SG' circuit where my Cap Dump PCB currently is. I attach the block diagram, schematic and draft PCB for this. The present PCB v4 that you are using can be used just to manage the supply from a PSU, so standing in for a supply battery. There are some features on the PCB, such as various sockets and diode placements, that will allow various transistors and diodes to be tried.

I see you are using R45 rods in place of the suggested R60. I can't see the small alloy variances making much difference. I won't be gluing in place and the glue doesn't add any electrical properties anyway.

Yes, ferrite rods are very brittle!

Julian

[pearldragon]

Hi Julian,

COP
Yes, will do more proper measurements, probably as you described them, once I;m getting closer to the right settings for the battery I’m currently using.

HV peak measurements
The attachment I uploaded contained a mistake: 3rd test was not done with STP20N95K5 but with STP12N120K5. I corrected it and uploaded the document again as a REV 02.
I did not use the voltage divider, but my 100:1 probe. I did not record the temperature, will try to do so in the next test, but they were both done around 10.30pm after a sunny day, so temperature should have been more or less the same in my room.

Swapping
You state: “so far I have not found the charging battery to rise above its starting voltage when swapping is involved and the elevated charged status is then used as the supply.”
That statement applies then for the pure radiant charging correct?
As mentioned before; JB said that this would not work by swapping the batteries with just radiant charging. However, I do not say that we should not retest and try it anyway and/or in different setups that JB has not tested yet. And when thinking about his statement, I wandered how it applied to his 1984 machine since there he was using 1 battery part of the cycle cranking the shaft, part of the cycle catching the ‘radiant’ spike from the coils…
If I remember correctly Paul Babcock mentioned that the timing of the swapper was very important, around 3min out of the top of my head.
As mentioned before, some other routes to try with the radiant charging and the battery swapper is the setup mentioned in the 3^rd bedini handbook (out of the top of my head), where there are 3 or 4 batteries involved (I understand changing to that setup might not be done overnight). Maybe there are a couple of different setups, but I need to think about it longer… will add it on my ‘to-reply-list’ to you that is growing .
For sure would be nice if you’d be getting a reply from Paul.

SG setup
Could you elaborate a bit more what you mean with going to a more SG style setup? Because if you mean using the common ground (generator mode) circuit setup, that would definitely be another thing to try with sapping. JB said that with a cap dump or common ground mode setup you can swap batteries.

Welding Rods R45
I did not ‘jam’ them, but they’re not epoxied in either: With a magnet I can get them out.: I still want to be able to replace them with the ferrite cores. I got 4 turned to the right size, and then my last two were to brittle and broke during turning. Ordered 3 news ones, received them, just need to take them back to the turner again.
Specs: https://certilas.com/en/product/g1#content

Best regards,
Rodolphe

[JulesP]

Hi Rodolphe,

It's good to see that you are starting to make measurements.

The 0.5 value you have got so far is fairly consistent with standard electrical behavior and efficiency for converting the supply to HV pulses. Although strictly speaking a CoP value is a ratio of energies (energy out / energy in) and not Charge (Ah), it will be interesting to see how your figures might change when if you use the method I described in my first interim report (CoP), in other words using stabilized battery voltage as the focus instead of Ah in and out. Given that I have yet to achieve any net gains under load producing a CoP>1, with HV pulses or Cap Dump discharges, perhaps using Ah in fact gives a more accurate and meaningful result? If so then that leaves the burning question of why the charged batteries show very elevated voltages after pulse charging and resting.

Your HV peak measurements are generally to be expected although it is interesting that on a different day you got a couple of hundred volts higher with the 95K5 device. Once I had a reading for a device, I would take that as a reference value as the divider can drift with temperature. Was the ambient temperature very different on those two days? In effect, I would tweak the divider adjustment knob to give the reference reading when doing subsequent readings.

I am in the middle of trying 'pulse combining' (see attached) which has been difficult to achieve in that, for some unknown feedback reason, my FET driver chip would be destroyed within a few minutes of pulse mixing. I have now bypassed it for the purpose of these experiments since unless I test this idea and method of working, I will not have a complete picture of what might improve results.

Generally speaking though, so far I have not found the charging battery to rise above its starting voltage when swapping is involved and the elevated charged status is then used as the supply. It is possible then that at the moment, for reasons not yet clear 'radiant' effects are not manifesting to a noticeable enough degree, even though all my CoP tests, using battery voltages, would indicate otherwise. However, I have yet to try a 3.2kV and a 4.5kV IGBT device to see if almost tripling the spike HV will induce some as yet unseen effects. These are the voltages that Babcock uses to go beyond the 'ether tidal region' as he describes it. However, he has not responded to my communication with some queries based on his 2022 talk.

So after these experiments, if I see no improved results, I am going to write up my load experiments and then follow the advice of a contact of mine and reconfigure my system as a more basic SG-type device to try and get some key radiant effects and then change one thing at a time to 'ramp it up in size and power over time. This will perhaps be the optimum way for me to find out whether, for example, impedance is the major blocking factor and where it matters most, or something else. So in a sense, I am doing the reverse of what you seem to have done and I need to reverse up a bit to better understand what 'ethertricity' actually looks like and how to observe it in a battery and then how that can be enhanced with HV only or cap dump pulse etc. I am already gathering components for a single coil system, without having to change the general physical design of my generator, (only replace the cap dump circuit with an SG one) so will get to that in due course.

Is your welding rod strictly R60 or regular copper-coated mild steel? I can't see that a small amount of Mo in the mix would make any difference. Also did you epoxy them together or just 'ram them in tight'?

Now I feel I ought to be doing some garden weeding!

Regards,

Julian

[pearldragon]

Hi Julian,

Thanks for the update/info to solve the spike issue with the amp meters. Will implement those caps (at some point) in my device as well (currently blew up both my meters ).
I want to respond a bit more elaborate on your post, also on some previous ones, but still looking for the time to so, so for now I just share some of my initial ‘quick and dirty’ results.

COP Tests
Quick and dirty, because I wanted some ball park COP (Ah in versus Ah out), numbers and as long as they are far below 1 and/or, not a noteworthy change compared to a previous measurement I don’t care too much about the accuracy yet. So to explain what I mean with that/how I performed my measurement so far:
-Discharge 1Ah out of my output battery
-Next day charge with the Solid State Charger (SSC)
---Noting every 5 tot 10min the amp reading on the display of my power supply (see image below). (this measurement is probably a bit inaccurate, still have to start using my recording multimeter)
---Record the rising voltage in my output battery with the CBA
---Stop charging at 14.30V (since that is where my conventional charger charged to as well
-Wait for an hour (while recording with CBA)
-Then start at step 1 again Discharge 1Ah.

For the calculation of the Ah the PSU put in I took the amp reading @ +/-60% of the charge time, and multiplied that by the total time of the run; as mentioned this is very rough measurement.

Generally I would do one charge + discharge a day, except for the first tests (ID 230528 CM & 230530 CM), there I did two full charge/discharge runs in 1 day.

Test IDs 230528 CM / 230530 CM / 230532 CM / 230534 CM are done with IRF840.
Test IDs 230601 CM / 230603 CM / 230605 CM are done with STP20N95K5.
Rest of the settings can be found in the attachments.

Conclusions/follow up actions:
-For test ID 230528 I did not discharge 1Ah out of the output battery the previous day, but 4 days ago. The COP is therefore +/-10% higher then when I discharge the previous day. This I noticed as well with the Bedini SG, sometimes this difference could be even far more than 10%.
-With currently selected settings no significant difference between IRF840 and STP20N95K5.
-I was planning to continue testing with the STP12N120K5, then STW12N150K5, finally STW12N170K5, but reasoned that finding the right frequency might be more important to figure out first, so will probably focus on that as a next step.

Peak HV pulse of active devices
I re-did the measurements, this time a bit more in a reproducible manner so I could track the increase of peak voltage over a couple of minutes and comparing the different active devices. I included my measurements for the IRF840 / STP20N95K5 / STP12N120K5.
UPDATE 2023-06-05 -> Replaced attachment of active device measurements, contained a fault: 3rd test was not done with STP20N95K5 but with STP12N120K5.

Best regards,
Rodolphe

[JulesP]

I'm sorry I forgot to include the issue of spike effects on the meter. Yes, initially I had a similar issue with the meters being unable to cope with the HV spikes being added to the DC voltage, although the main battery should normally act as a sink for them to effectively dampen them, so theoretically they should not reach the meters.

What I did was put two small capacitors (100uF, 50V) across the negatives and the meter voltage feeds as shown in the attached graphic and the photo, and that seemed to solve the problem.





The graphic shows the wiring for the panel that holds the PWM module, with its own On-Off switch, and the two small (not very accurate) panel meters.

Your spike voltages are good for the device used (IRF840) although seem to be switching off slower, hence the curved slopes. Off course the time base you are using will change the appearance a lot.

J

PS. Please note that my inserting the ammeter into the negative line via the plug panel is not in fact the best place for it to get an accurate reading. I found that going from the supply battery directly to the meter and then out to the negative line was best. I can give more info on that if you need. Of course, with battery swapping, you can't really use a digital meter since when the meter is in battery line during the charging stage, it won't like the spikes and may damage it so I used the configuration shown with swapping off for the CoP tests, and also similarly when substituting the supply battery with a PSU.

[pearldragon]

Hi Julian,

Some quick HV pulse measurement results with the following setup:

-100:1 probe between H19 and H10/H14:
-IRF840 as active device
-100Hz / 50% duty cycle
-Input battery voltage under load: 12.07V
(-Input battery voltage @ rest: 12.13V)

-Air coils (no core material) 62.31mH/coil: 656V (see image below)

-Welding rod as core material, 267mH/coil: 632V

The max voltage of the peaks seemed to be climbing slightly when leaving the machine run. E.g. with the welding rods it started out at +/-596 and climbed to 632V. It might have climbed a bit further if I would have left it on longer.

Regards,
Rodolphe

[pearldragon]

Hi Julian,

Just a quick update:

-Replaced the IR2121 and the last signal of your post #85 did appear (with SW5 switched ON). See attachment. Post 88 - measurements.pdf

-After finishing the chapter ‘SWITCH ON & DIAGNOSTIC CHECKS’, I connected the coils and with a battery on my input and my output, I switched ON SW5 (FET Driver). I had a separate multimeter connected to my output battery to double check that the voltage would increase which it did.
However, when I looked back to the panel meters, I saw that the panel meter for my output battery was not functioning anymore. I had one spare, replaced it. Switched on the machine again and the moment I switched ON SW5 again I toasted my spare panel meter as well .
I double checked your panel meters* and although the PCB components look slightly different than mine**, for the rest they look very similar.
Just to double check: your output panel meter did not blew up?

*
https://www.ebay.co.uk/itm/154574694810?
**
https://www.ebay.nl/itm/394215176060...3ABFBM5Nf9sbth

-I have some minor updates for the manual, but will e-mail you about it.

Best regards,
Rodolphe

[JulesP]

I will check when I get back off holiday.

J

[pearldragon]

Hi Julian,

I’ve been/am snowed under by other stuff currently, so time spent on the machine has been very little unfortunately.

Before I redo my measurements/check and compare with yours, just one thing to double check:
You write before showing your measurements:

“Regarding your PWM measurements, you should see the following traces on the various TP points going from the PWM input on H37-1 through to the Driver output/ FET Gate input on H22 (yes that should be H22 in the manual) and with the Driver off (SW5 off).”

In your last image/screenshot, from the H22-1/2 TP (from output pin 7 of the Driver) shows a square wave, giving me the impression SW5 was ON there. Or do I misinterpreted?

Best regards,
Rodolphe

[JulesP]

Hi Rodolphe,

Bad connections have been a problem with me on occasions when a circuit error occurred and only by going through every possible option step by step in a logical way, and including the most unlikely things, was the fault found. In one case a biasing resistor for a transistor, that is involved in switching on one of the cap dump routing FETs was not in fact 10k but around 5ohms! Is it Murphy’s Law or another one? So now I check each component before I solder it in place.

When I ‘hot’ recharged a battery after a test involving a controlled discharge and then HV pulse charging (as in the regular CoP test run), the battery would be left till the charger naturally stopped and then usually left overnight. So long as you know the voltage when you start a controlled discharge, and then leave it for an hour or more before you start the pulse charging, then it shouldn’t really matter what voltage is reached. You’re not expected to have a ‘globally’ consistent value and each test I treated as its own independent one.

I expect batteries and capacitors will both display an ‘electret’ effect that will boost the voltage a little but the degree and significance are worthy of another whole study!


Regarding your PWM measurements, you should see the following traces on the various TP points going from the PWM input on H37-1 through to the Driver output/ FET Gate input on H22 (yes that should be H22 in the manual) and with the Driver off (SW5 off).


H37-1 and H17-1/2 where you should see the PWM square wave input as here, so about 7V max:




H13-1/2 where you should see the inverse of the above but it will probably look the same timing-wise on the scope. If not then replace the 2N3904 and repeat




H16-1/2 where you should see a similar square wave but I expected a lower voltage as it enters pin 2 of the Driver. It reads 100V since I noticed later that I moved the x10 switch on the probe, so really it's 10.0V.




H22-1/2 there should be a similar square wave of increased voltage to 'hard drive' the FET gate for rapid switch on and off. Again this is really 12.6V max.



If not then switch out the IR2121 chip and repeat.

These checks should allow you to zoom in on the problem.

Regards,

Julian

[pearldragon]

Hi Julian,

Swap LED 3
I disconnected SW 2 completely (Swap On/Off), but LED 3 still lit very dimly as before when switching on the main switch. Maybe it relates to the topic below?:

FET driver chip / U2 / IR2121 issues/signal
For the measurements below the following things/settings were used:
-Jumper 4 and jumper 5 capped (connected)
-None of the 5 coils was connected to the PCB
-PWM module “V-“ and “Ground” connection connected to each other (and together connected to H34 (PWM-)
-C7 is indicated on the electrical schematic as a polarized capacitor, I used a non polarized:
https://www.reichelt.com/de/en/folie...NGUAGE=EN&&r=1

1) H13 & H16, SW5 OFF -> approx. 10V square-ish signal
When I disconnect SW5 completely, the signal stays the same (=no leak through switch).
2) H13 & H16, SW5 ON -> approx. 12V Square signal
3) Pin 1 IR2121, SW5 OFF -> approx. 8V Sawtooth-ish signal
4) Pin 1 IR2121, SW5 OFF, PWM module OFF -> approx. 8V signal
5) Pin 1 IR2121, SW5 ON -> approx. 12V signal
6) H22/Pin7 IR2121 SW5 ON -or- OFF -> no signal

I assume 1) 3) 4) are signal readings that are not supposed to be there with SW5 switched off. Do you have an idea what could be wrong/what I should check?
Post 84.pdf

Manual update, page 47:
Where it reads: “…then an output should be measured at TP-H17…”
I think it should read: “…then an output should be measured at TP-H22…”

Best regards,
Rodolphe