The caps together are at 120v dc but I wondered if a transformer could be used. It is at 365v dc after rectification but if I connect 4 batteries in series/parallel could they safely be charged with the transformer?
The capacitors voltages aren't at 120V DC because they're before the bridge rectifier. They're connected in parallel to each other but they're in series according to the bridge rectifier. Their capacitive reactance is what is limiting the current, in a similar way to the concept used in capacitive transformerless power supplies. The unregulated DC at the output of the bridge is actually around 169.7V less the equivalent voltage drop of 2 diodes of the bridge. As far as adding a transformer after the bridge, I would be lead to believe that the resulting voltage would be negative as it would be 180 degrees out of phase with the primary. Even if the resulting signal/positive is positive, you would require a really beefy transformer to handle the current. Also, keep in mind that if you put the transformer after the bridge, the maximum output current the transformer will deliver will be an inverse ratio of its voltage. Simply put, if the transformer gives you a voltage ratio of 1:2, the current will have a ratio of 2:1. In a perfect world, the power at the input of the transformer is the same as the output, but things being what they are, there will be losses induced by the transformer conception. On the other hand, if you put your transformer before the caps, you'll have to be careful with the capacitor ratings, the transformer rating as well as the bridge rectifier specifications. If you're not familiar with capacitance, capacitive reactance and specially the security rules that must be respected when dealing with mains voltage, I'd strongly suggest you to opt out of this project. It's not like dealing with low voltage projects, errors might not be as forgiving. Keep in mind, your loved ones would prefer talking to you than talking of you !
hello bruni auti...are the capacitors connected in parallel with a switch in between capacitors so if you turn the switch on the other capacitor connects in parallel and increases the value of the capacitor? thanks in advance.
Wire in a small a.c. fan motor between the black a.c. line and the neutral.....when you turn your switch off, the running motor discharges the capacitor instantly, making it safe....
Hooking caps together...how many output volts dc after rectification, would be safe to send to the battery? I have 2 badly sulfated 6v Trojans connected in parallel for a solar array project. Would really like to get these reconditioned so I can use them. Right now they are at 9.75vdc at rest and top out at 12.5 vdc when on charge. I have 2 caps in series @ 120 vdc after rectification. I also have a transformer that puts out 365 after rectification. Is this safe?
It would be much easier if you could share a schematic of what you've done so far, with as much details as possible, specially the transformer specs. What I find ambiguous here is the fact that you're mentioning that you have 2 caps in series @ 120 VDC. How did you measure that 120VDC ? What are the caps ratings ? What was your action plan when you decided to put 2 caps in series after the bridge rectifier ? Not having a clear picture / understanding of your setup would prevent anyone from answering your "Is it safe ?" question. Dealing with mains voltage projects can be dangerous if not properly handled. Related questions can't be answered adequately if the situation isn't understood clearly by everyone. Margin for error is fairly slim. You won't get a lot of chances of being pinched by a 360V spike. Usually there will be 2 occurrences : the first one and the last one. Neither one is desirable, believe me.
Without being excessively fancy, I think I'd add some voltage monitoring that would activate / deactivate relay(s) to switch between current ranges or simply turning the whole thing down with some sort of audible / visual indicator. Murphy's law always prevail. If you start the process for one hour with your timer and you have to leave, there is nothing that can guarantee that nothing will happen while you'll be away. Monitoring the voltage and temperature would more likely be the 2 crucial elements to keep an eye on. I'm familiar with mains voltage appliances and many circuitry but exposing a lead acid battery to that type of "gymnastic" is raising some concerns. At least your setup looks solid and well made. As a suggestion, consider putting bleeder resistors for your caps. For instance, a 200K resistor across 50uF will take roughly 1 min to fully discharge so if someone touches the leads he/she won't get a nasty surprise. Capacitors are well known to keep their charges for a long time.
Yes great advice, bleed resistors have been added to the capacitors and I am working on a voltage monitor that will stop the charging process if the voltage gets greater than 16VDC.
As per what I read so far, overcharging is part of the process. Some people even suggest 17V but at a lower current rate, such as 500ma to 1 Amp. As a suggestion, you could consider making a small discharge circuit with a led, a DIP full bridge rectifier, a zener diode and a couple of resistors so that the led would indicate the presence of High Voltage and would gradually dim out when you turn off your device. When we "see" what is going behind the scene, usually we somehow feel more secure. By the way, if one of the caps breaks and creates an internal short, your overcharging circuit will need to be able to handle 170V and pull the plug right away because I don't think the battery would be too happy of the outcome. If this situation isn't tripping the breaker(s) , you will end up with a very dry battery as it will certainly boil. When dealing with mains voltage, Murphy is always close by !
I saw the two breakers but didn't know how and where they were connected. If you have some spare time, it would be nice if you could provide a schematic. I'm actually creating a BOM so that when I'll have what I need, I'll more likely build home. There are extra features I'd like to add, one of which is to make a more elaborate use of the capacitors for some other purposes just by changing some connections. Such high voltage caps could also be used for a power factor correction device and potentially be used as an alternative to power resistors in the conception of a soft starter / inrush current "killer". Configuring the caps as a voltage divider might be something to consider, thus allowing to limit the voltage fed to the bridge rectifier for different scenarios. The idea behind this is simply the fact that if I need to spend money on parts like these, I want to make the best use of them and if I can make these projects somehow modular, so that the capacitor bank can be set / configured to accommodate different purposes, that would be even better, at least to my point of view.
I built one using your design with a 50 and 45 mf cap...works great but where does the pulse action come in? I've taken a poor battery(10.6v) and charged it to 14v but when I take it off harge it drops down to 11.9v. Better than before but I wanted to know what causes the pulse action which will fix the battery once and for all? I put it back on charge to see if it goes over 14v. Wait and see...
@@Mr05Tundrathe pulsing comes from the caps, once the caps fill up it disperse the power, then builds up and releases, thats how pulsation occurs. Sometimes you have to charge it for awhile, then let it sit, come back to it the next day and do it again, do this several times to get the plates to shed, and sometimes the plates are burnt and cant be fixed without replacing plates.
using just one diode istead of gretz would do the pulsathing thing. desulfating on this tupe chaeges does not works on pulsating efect, rather it appleys high voltage low curent on sulfated batreries
I don't understand this. I do understand how a capacitive dropper works, but surely the waveform from the bridge rectifier used to charge the battery will be the same as from an old-fashioned simple transformer + bridge rectifier charger? How is this better at desulphating?
@@ryanburbridge I get my info from Chargers I have built using the guidelines outlined in a published document titled "Capacitive Battery Charger by George Wiseman" published by www.eagle-research.com. copied from the text, paragraph 12 page 1 "It is a tested fact, that my CBC of the same amperage as my transformer charger “draws” 57% less power from the AC source, tested by a watt-meter. I’m sure that there are transformers of greater efficiency than the one I tested. But this should indicate to you how I assembled in a few minutes from surplus parts ($5) a battery charger that flat out beat a “store bought” charger, for which I paid $40.00."
P Hubenette awesome! Thanks bud. I just repaired my $500.00 plus associated 6006 and was amazed at how simple it was. Realizing i may be able to build my own to supplement different needs. How did you like that rebuild video lol
@@ryanburbridge I hear what you are saying. It pushes me one step closer to making some videos of my own. On a side note, I spent countless hours researching info on Capacitive Battery Chargers and kept coming up with vague & useless info on the subject. I found many references to "George Wiseman" but no specifics to anything he had published. I finally gave in and purchased the document from eagle-research.com That said, I believe it was worth the price but from my perspective it only served as a guideline & confirmation on the construction of the unit. As long as you possess a basic knowledge of electrical engineering I think you would be fine moving forward using trial and error.
Commercial chargers are built to be simple and safe. Yes there is considerable loss, because the transformer produces heat, which is lost energy. Anything with a capacitor in the output circuit is dangerous, plus this puts out very high voltage.
I'd be lead to believe that putting batteries in series is something that could be done assuming you have a good idea of the respective batteries conditions. If you have a cell in a battery which is "opened", you'll face a dangerous situation. Not only nothing will happen to the other batteries but you'll end up with a much higher voltage differential between you positive and negative leads. If you don't pay attention, that will kick you a$$ badly. In fact, would it be only one battery or more than one, an open circuit will lead to an increase of the output voltage as no current is circulating. You don't want to be the one to close the loop, believe me !
