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607 Threads found on 12v Battery
I am designinging solar MPPT charger, in which solar panel voltage ranges from 100 to 180 and the battery is of 12v. battery has to be charged by 2 modes stand-by(13.6V) and cyclic mode(1405V). I am using SEA05 controller for constant voltage and current. can anyone suggest me how to switch the mode to stand-by mode when (...)
I'm trying to use an LM358 as a voltage comparator to test the voltage of a battery connected at the output of my system. (I know that I can use an actual comparator IC like LM339, but I'm trying to do it using the 358 so please bare with me) I'm only using one of the opamps and left the +/- input pins and output pin of the other opamp not con
Hi, I am new to this field. I want to reduce wattage of my car battery in to 3w (i.e. 12v with 0.4 amp). Actually I want to run different types of leds ranging from 3w to 20w in car as drl. There are ready made drivers available for it but it becomes costlier and it is little bit difficult to connect more than single led in one driver.
Hi there, Here is a little audio amplifier I would like to try, since I have the tube and the headphones. However, I would like to provide the filament voltage from the +12v one, so that a single 12v PSU can be used, without the need for the battery. I do not want to use semiconductors. The filament draws 240mA at 1.2V. Can a simple voltage (...)
7812 have ~2V minimum voltage drop. That's why I doesn't work. Even if you will use LDO, this solution will be poor. You need to clarify more details about your panel. How strictly it needs 12v? In this case SEPIC DC-DC converter have to be used, but this solution is expensive and efficency will be poor also (60-70%). May be direct connection will
Hi, I'm looking to build a charger to charge 2 x 12v 12ah lifepo4 batteries in series, that can charge fairly quickly. I currently have a charger for 12v 12ah lead gel batteries with a 80va transformer (not sure if that makes any difference to this question), could I just use this? ps, I have little to no knowledge of electronics so please bare
A typical embedded system, let's say Transmission or Power Train Electronic Control Unit (ECU) is powered by automobile battery. battery voltage is at 12 Volts. If the battery voltage drops to 0 Volts in 5 us and stays at 0 V for 100 us, then rises back to 12v in 5 us, what impact will this have on Microcontroller (...)
You need to boost the voltage, a cigarette lighter socket will give less than the host battery voltage because of drop along the cabling. If you want to charge a 12v lead acid battery you need MORE than 12v to do it, in other words you can't use one battery to charge another of the same type. If your vehicle (...)
12v 75W Solar Panel I did tests on my PV panels rated 64W, thin film type. Open circuit voltage 23.8 V. Each panel delivered 3.4A to a 12v lead-acid battery (bright sun high in summer sky). I found that I did not obtain 64W into a 12v battery. Expectations might lead me to think it should mean 5A. However (...)
this tester will show battery capacity after discharge to preferred minimum voltage value and than disconnect load. end of discharge is marked by sound from
The internal resistance forms a voltage divider with the load. If the voltage is 12v with no load and drops to 6V when the load is 1 ohm then the internal resistance is 1 ohm. But the voltage will not drop that low, maybe it drops to 10V so the missing 2V has a current of 10A and the internal resistance is 2V/10A= 0.2 ohms.
Hi there, I have owned two UPS at the past. The one was a small 600va with AC in and AC out (mains) The other was a DC UPS, meaning AC mains in and DC 12v out. Even though the second UPS had a much smaller battery and it cannot power up big loads,
Can a 12v battery charged by lower voltage input like 10v,6v etc ,make me detaily understand about battery charging concepts with respect to both current and voltage a lower input voltage than that of battery cannot charge it.
I see nothing wrong with that. The red probe is across the battery so it shows +12v with some ripple due to its ESR. The blue probe shows 10V RMS sitting on a +12v platform so I would expect it to peak at around (10 * 1.414) + 12v and dip to 12 - (10 * 1.414) which is exactly what it shows. Brian.
Imagine we have two items. 1)A "U" volts battery with two terminals "+" and "-" (e.g. 12v car battery). 2)Thin copper plate of size AxB. It is neutrally charged - number of electrons equal to protons. I touch a "minus" terminal of a battery with this plate (plus terminal left floating). The main question of this (...)
The regulator is probably so the speed remains constant for as long as possible. If you connect a 12v battery to a 12v fan it will run but as the battery discharges, it's voltage will drop and the fan will lose power. Depending on the motor type used in the fan, it will either not try to rotate as fast or it will lose (...)
I have a transformer of an old UPS Implying it steps up 12v (24V) to mains ACV. A clever designer might (for all we know) install more windings to step down mains AC to charge the battery pack. It will require a lot of testing, if you wish to figure out step up/down ratios, etc. Take ohm readings. Make a list of all
You want to charge main HV or 12v battery? Don't you think it can be dangerous?
For typical 12v lead-acid battery, these are normal limits: Drained: 10.5. Charged: 14.4 Scale down these values to match your 4V battery. Or else it may be more important if the battery is a power source for a circuit. Then you may want to set your alert where battery voltage is too low or too high for (...)
Dear brothers , I need little help , I have build a electric fence energizer , it runs by 12v 7.2ah battery , which I picked it from my computer ups , so I need that battery charger circuit from my 18v liner transformer , and I have a 12v 10w solar plate , can I charge my battery with my solar panels , (...)
Dear members , I need a circuit to charge my 12v 7.2ah battery from my linear transformer which is rated 15-0-15 v , and I have a solar plate which is rated 12v 10w , please send me one circuit design , I am newbee Please send me charger circuit
Hi I'm doing a equipment integrated testing.. It has got two PCBs . Equipment has a 12v battery and One AC /DC supply generating 15V from mains, both are ORed and given to one board which generates 10V using buck and gives to other board. Both the boards has got some microcontrollers and generates lower core voltages required for their operation
dear all I have a circuit consuming 120mA current on dc poer supply of 12v. I have a battery of 6.8mA, 12vDC how can I calculate the estimated time that this battery can provide for 120mA consuming circuit. Thanks in advance.
It does not seem likely that the unit would have a single 6V battery, delivering 750W. That's over 125 Amperes. When I opened up my UPS, I saw four 6V gel cells, in series. 24V total. Perhaps yours is similar? Can you open the cabinet and see whether you could hook up your 12v battery? Or perhaps it needs two. You may need to attach (...)
Concept of buck converter. 12v stepped down to 5V This is not necessarily a complete circuit. The inverter is a 'shortcut' component, to illustrate how the feedback signal operates. For the control circuit you ca
It states: "3.PWM charging algorithm with auto charge set point according to the battery voltage" which includes nothing about current limiting, only that it auto detects whether a 6V or 12v battery is connected and selects the charge point (target battery voltage) accordingly. Brian.
I run a car stereo (actually I use the pen drive only) from a 12v 1A (SMPS) power supply that was from a old printer adapter. I guess a 12v6AH would be sufficient to run for 1H with pleasure.
Hi, so simple calculation: W x h = Wh You need 125W x 10h = 1250 Wh a battery with 12v: V x A = W; W / V = A; Wh / V = Ah 1250Wh / 12v = 104Ah But these calculations are "best case" calculations with 100% efficiency. Add at least 20%-25%: --> 130Ah --> you won´t carry a 12v 130Ah lead acid battery (...)
How to connect power sources in parallel? I need to create DC source of power 400V 1A powered from 12v battery. I see on EBay inexpensive 12 to 400 DC/DC converters (output voltage adjustable) rated at 70w. I assume each one will give me 100mA. Can I connect them in parallel to get 1A output? I assume I can adjust output voltage with a meter wi
Hello. I am looking for a circuit to convert a single positive low voltage(a 3,7V Li-ion battery so 3,2V-4,2V, or 5V) into a symmetrical power supply of somewhere around ?12v while delivering up to at least 1A for each rail. I find a few simple circuits using different IC's to convert 5V into ?15V but they do never deliver more than around 20
Have someone ever used the LT3650? I have designed a circuit charging a 18650 battery. It works ok but the IC gets very hot (50C) at 12v input and over 65C at 28V. The IC has about 20mm? of copper on the bottom side and about 10mm? on the top side. Charging current is set to 1.5A. IC should have thermal shutdown but is this heating normal? I
Batteries tend to self-discharge if left to sit for a long enough time. They have a longer life if kept fully charged. Is your 12v battery a lead-acid type? Sulfation is the common problem which they develop if left idle for a long time. It is not easy to determine if you have this problem. There are techniques for removing it, but it is not easy
Hi all, I need a small help regarding L293D. I am making a small project using L293D. Bo motor which hardly consumes 60ma at 5v. i am powering my L293D using a step up circuit 3.7V to 5V from 3.7v li-ion battery. output current from step up circuit is 200ma which is not a issue. my problem is the motor voltage pin no 8 shows me 5.12v. when i d
Hi, I need an assistance to chose the right diode values for protecting the circuite from reverse voltage and current protection. vin 12v, max forward current /consumption of the circuit can reach 7A. do i need to choose a 7A max forward current? can anyone specify example models? is it better to use a schottky diode as to fast responce
Even if you had a DC-DC convertor to drive the motor controller, look at the difference in cost and size of Supercaps and batteries. How many Farads would you guess is in a 12v 40Ah lead acid battery from Q = CV The lead?acid cell in practice gives only 30?40 watt-hours per kilogram of battery. Electric Double Layer Capacitors, Supercaps (...)
Assuming your PV panel is rated 50W at 12v, and your battery is 12v type. It is common to have a buck converter, to prevent overcharging the battery. A good upper limit is 14.4V (for a lead-acid battery). By tapering the charge rate, it avoids pushing the voltage too high. Otherwise the electrolyte would (...)
I think the circuit works by monitoring the 12v car battery, when some one opens a door the interior light comes on and takes current and the battery volts fall. Q1&2 are a bistable, normally ON, when a door is opened the battery volts fall faster then the volts at Q1 emitter, so both transistors go OFF and allow the (...)
Hi I have a 12v full bridge operating at 100KHz, driving a transformer. The transformer output is rectified and filtered with a capacitor and then connected to a resistive load. The 12v input to the bridge comes form a pair of 1.5 meter long copper cable, 4mm in diameter. The rail voltage is very unstable. The pk-pk ripple is roughly 5V at 40A c
125325125326125327 i made this circuit for my 12v batter and is working
yes, your solenoid has a coil resistance of { 12v / } = 30 OHMS fOR A really green solenoid, it would have a coil resistance of almost nothing, and you would power it with a constant current source, but that never seems to happen. Even in electric showers, the solenoid alone dissipates 10W of power when you are in that showe
If your regulator is a 7809 then its input must never drop to less than 10.5V. Then it does not pass any input noise if it has the input and output capacitors recommended on its datasheet. The input voltage will probably drop to less than 10.5V if the engine starter is used and when the 12v car battery is dead. I have never seen an electric motor
Hi all. Ive just bought a pcb heatbed, the kind used for 3d printers. i want to try and power it with a few lithium batteries. to do this i need to convert the dc from the batteries in to ac. you can purchase power inverters but they step the voltage up to 220. this heatbed only requires imagine that its probably quite energy inefficient to
your arduino and GSM shield are 5v. the solar controller (at pins 3 and 4) gives 12v. did you take care of these voltages?
A Lithium-ion battery cell is 3.2V when it is almost dead and its load should be disconnected and is 4.20V when fully charged. Then its average discharging voltage is 3.7V. Three in series make 9.6V to 12.6V which is not a constant 12.0V. You could use a 12v voltage regulator and four battery cells in series. The Ah rating is not its (...)
Hi guys, I've a vehicle tracking modem which is going to connect in a vehicle has 12v/24vDC battery. I just need to connect a backup battery(12vDC) to modem for uninterrupt power supply i.e if 12vDC/24vDC battery goes off, want to switch over to backup battery. (...)
Can I use a computer power supply adjusted on 12v & 12A to charge a car battery. Thanks in advance.
the ground of AC supply is different (from 12v ground). therefore no glow of bulb with battery + and ac ground pin. and bulb glows in 12v and its gnd(-) point. the term 'ground' is to be used with its own circuit.
How can i design a converter from 48v to 12v ? the 48v came from batteries needed to be connected to a 45kw or 60kw generator instead of it's 12v battery to take the first latch. thanks in advance Hi 45 /60 kw inrush power ?!!! buck converter with such a high power can be made but it require a lot of experience and money ! Bu
Hi, I came across a page on using a dvd player's power supply to run a load here. I was thinking... maybe to get it to work as a trickle charger for charging a 12v car battery. After all, a dvd player would not draw high current during operation. However, i am just not sure about the ACTUAL output vo