Voltage and Amperage reduction

I'm sorry! When I'm talking about using the electric motor as a source I mean the power lines that supply the electricity to it. Those lines supply the motor with 230VDC and the load from the motor is around 90 Amps.

My idea is to charge the battery only when the motor is running so the motor gets must of the electric load and the battery only gets the small part that it needs.

Is this possible?

Thanks in advance for your comments...

It is a pity that your supply is dc, as this does complicate things. If it was an ac supply, then of course there would be no problem finding a suitable battery charger.

As another poster said above, the only efficient way to do this is to use a switchmode voltage reducer. A quick google suggests that these are not exactly common, so you may need to find someone who can design and build this for you. It is quite technically feasible, but by no means a simple task and is well beyond DIY territory.

This is the situation. The only available power supply in such space area of installation is 230VDC which is intermittently turned on and off [75% continuously cycling ...] On this space area is a need to power a device drawing a 5A load at 10VDC. Actually I had one...and another one...but they all burnt because they are not designed for the intermittent factor of being turned on and off...24 hours all week...

any advice is a relief...I need help on drawing applicable circuit to utilize the existing

230VDC supply into 10VDC sufficient enough to feed 5A DC load cycling 75% continuously turn on and off without burning.

Have you thought about a solar panel?

Thanks! We already had some but the place is isolated and those panels were stolen...

Or solid state- Inverter+step down transformer+ rectifier.

Even DC Voltage choppers are available which will give you lower voltage once the output is smoothened (filtered)

Hello the issue is relative simple to be solved. All AC driven switchmode power supplies have a rectifier at the input - so if this international operation notebook battery charger is capabile to handle for instance 100V to 270V - which is rather common (Notebooks etc). The 250V DC at you motor will be inside the permissible range of operation (AC 240V is internall rectified so the the operating voltage inside the notebook power supply is much higher anyway!)

You should be able to hook up the power supply mains cable (life and neutral) directly to the DC voltage. The power supply can be connected to the DC Voltage without any problems. The build in rectifier will even make sure that you do not mind about the voltage source DC + / - pole. The rectifier will make that the flow of the current is correct. If this notebook power supply is choosen to provide e.g 13.8 Volts you can use a cheap battery charger with 12V input (available in Marine / boating / toy model stores) to charge the battery.

But it needs to be a widerange 100 to 270V AC note book power supply and use for safety reson a fuse in front of it.!!!!!

I think this will not work for two reasons. First is that Notebook power supplies operates on AC, which means that the input is AC, but here we have 250DC. I don't have any idea about DC to DC rectifiers (If I'm wrong please correct me). The second is that current handling capacity of the Notebook power supplies. Generally Notebook power supplies handle less current than 10Amps. But our friend needs 10Amps, hence again I think notebook power supplies will not work.

As Guest indicated, the AC is normally converted to DC, so yes, the inverter in the notebook power supply can be made to operate on DC. I have several notebook supplies that are rated 90-240VAC input. I haven't yet taken one apart, so I don't know the voltage rating of the capacitors and other components inside, but it is common practice to simply pass the supply voltage through a bridge rectifier, producing a DC voltage significantly higher than the RMS voltage of the supply. If you put DC into the rectifier, the rectifier will drop the voltage slightly and guarantee the correct polarity, again as guest indicated.

As to the 10 Amps, is that the charging current for the battery, or is it the current required to be drawn from the battery? if it is the latter, then the 1-3 Amps commonly provided by a laptop supply would charge the battery quite nicely. Obviously the current available depends on the particular supply.

This is not limited to notebook/laptop supplies. Many desktop supplies are now made for universal input as well, but they may or may not have the output voltage you need. Laptops commonly use batteries in the 10-20 V range, so a laptop supply is probably the most appropriate, if you can be satisfied with their current output. It will just take longer to charge if the current is lower.

In any case, you do need an appropriate charge controller for whatever kind of battery you are using.

Thank you! The 10 Amps is the MAXIMUM allowed to charge the battery. A charge above that will damage the battery! The electronic device that will use the battery has a load of 3-5 Amps.

Thanks again!

Cheko Try looking a bit further. The Phoenix model charger also has a universal input and can handle as high as 400V DC input Furthermore both Skylla and Phoenix models can be used with a remote control panel that has a control knob that reduces the maximum output current. Although this is intended to reduce the load on the incoming power supply it can equally well be used to limit current to protect the battery being charged.

Both Skylla or Phoenix will work but the Skylla has digital control whereas the Phoenix is analog. The Phoenix also has an analog meter on the face which may be of use to you. both units have adaptive charging.

As I said to begin with; download the data sheet and READ it completely. If you have 250 V DC as your supply and desire to charge either a 12 V or a 24 V battery at a maximum rate of 10 amps then the Victron products are ready made for your application. No need to reinvent the wheel or custom make something special. The controller can dial down the amps to whatever you want.

Just order it off the shelf wire up and GO!. Victron is used and sold around the world. Designed in Holland but built in India. I use their chargers and inverters because no matter where in the world my clients are located the equipment will suit local power supply.

At present I have systems being built in Turkey, China, and the USA, all of which use the same type Victron equipment and is purchased locally. Now if you happen to live up the Amazon or Zambezi river delivery is going to be a bit longer but in most countries where they already have electric power you can expect reasonable delivery times.Can't vouch for what customs will charge. One good thing about Victron is the fact they use switching technology so is lighter weight tjhan comparable old style transformers equipment. Weight saves on freight bills.

you will need minimal 13,2 V for Lead Acid and to have a complete load 14,4. Lead acid doesn't like the 10 amps at the end.

Which is why these chargers have adaptive charge regimes. It is common practice to only state the maximum bulk rate knowing that All batteries require tapering off towards the end of the cycle. that is what adaptive charging mean. Depending on where you set the limits and transitions you can also charge a battery that requires a nearly constant current right to the end and these chargers have a temperature sensor so as to avoid over heating the battery.

This technology is a decade old. Doesn't everyone know about it and use it?

Regards.

Constant current chargers are suitable for LeadAcid batteries as charging alone [Not in an automobile or as in Back-ups].

these types are used from the 1970s/ or sometime before when NiCd batteries came in. But these chargers have timer to bring it to trickle charge after specified time.

LeadAcids are charged on contant voltage; as the condition of battery improves it end voltage rises charging -current decreases and at full charge condition the current is as low that it does not damage the battery even if remains on charge for long times.

These barries raise the end voltage linearly with actual charge.

NiCd & latest batteis has a problem of raising end voltage almost instantly [say some minutes of charge] so cannot be charged on CV but need CC chargers.

There are lots of other refinements in these chargers like sequencial testing on load condition etc etc.

okay, so what is it about the Victron chargers you don't like and why don't you feel it is suitable to the intended application?

Thank you very much! I found the information and that's what I´m looking for.

Cheko have a look at the Skylla. It also has provisions to work as a power supply without a battery being needed. I sometimes use it as a battery substitute when the old battery is toast and the replacement has not yet arrived. Very handy product.

Lot of DownConverters may be in market.

Ask for your requirements:

zahn@zahninc.com

220-250volts entry/12amps maximum if it fits your needs,look for in the web;electric charger 12 volts, maximum 10 amps

when amperimeter shows 10 amps.u stop it

I hope this helps u

If a transformer is present, don't use it.

Your post is incomplete! Virtually all switching mode supplies use a (high frequency) transformer to step the voltage up or down after the switching device.

What you should have said is something like: "If it has a 50/60 Hz input transformer, don't use it.

Virtually: except the algorithm "n"th order harmonics chopper, that only has coils, resistors and capacitors. Your comment however is (virtually) appreciated.

Checko; Go to www.victronenergysystems.com website. click on Pruducts then Chargers and you will see they have a Skylla model charger which is advertised as universal input. Not only will it accept any frequency and voltage from 90 to 265 V AC but it can accept 200 volt or so as well. Read the specs carefully data sheet is downloadable.

I suspect this is going to work for you.

DC - choose it has no frequency DC is not transformable with AC equipment such as transformers only.

Try reading the whole thread. He is looking for a charger for a battery that is powering a computer. Doesn't matter what the battery is the Skylla is programmable for any battery voltage you can possibly want within th enominal range. Go look at the data sheets which details the adaptive charging routine for these chargers. I have been using these chargers for many years now and doing things conventional wisdom said was not possible. Yes I realize transformers are not usable on DC but these are switch mode designs and somebody else mentioned that for this kind of applications you need switch mode. design. Running a belt driven alternator from the 250V motor is a needless complication.

Maybe we should ask where he gets the 250 Volts DC from? Is it a remote nuclear plant? GA to you too.

Thank you both! Thank you all!

I don't have the battery yet, and originally I was thinking in using a deep cycle, but that is the easiest part.

"elnav" recommendation is to use a Victron Battery Charger. I found the specs for that equipment and it is capable of doing what I need it to do, so I'll look for a battery that works better with those chargers.

Thanks again to all of you for all your suggestions and recommendations to help me solve my problem.

You are very welcome, Cheko.

I had a feeling from how you've handled yourself here that the unanswered question on battery type was because you were handling this part of your puzzle. You are by allowing this to be a degree of freedom in your system selection. I look forward to hearing about your final solution.

Thanks! I'll let you know the final results of this solution. Thanks again...