Series and Parallel?

What is the difference between Series or Parallel if I'm hooking up a bunch of LEDs? Is one better than the other?

Question by Zem 9 years ago  |  last reply 9 years ago


Paralleling MOSFET's? Answered

Can you parallel 3 MOSFET's by wiring Q1s gate to Q2s source then Q2s gate to Q3s source, parallel the sources and drains of all 3 MOSFET's together then add some diodes (the diagram is below)? They will be oscillating so no balancing resistors are required.  

Question by The MadScientist 7 years ago  |  last reply 7 years ago


resistor parallel

Sir I need 100ohm 3 watt resistor but cannot find it in market, in market I find 100ohm 1watt resistor ,plz tell me how I acquire (100ohm 3 watt resistor) value. can I parallel three 100ohm 1 watt resistor to get my value

Question by robinhoodxx 4 years ago  |  last reply 4 years ago


LED in parallel to power? Answered

I have a project and i am wondering if you can hook up a diode to the power source (hook it up in parallel to it) would you have to hook it to ground in some way??

Question by astroboy907 8 years ago  |  last reply 8 years ago


Parallel Circuit question?

When connecting LEDs in a circuit in parallel, why do you need a resistor for each LED or LED series within the parallel. Couldn't you use 1 resistor connected to the power supply before the current even got to any of the LEDs in parallel?

Topic by mrshow555 11 years ago  |  last reply 11 years ago


Parallel circuits question

I am trying to make an LED grow light and I have an electrical question. I want a simple light grid, but I am not sure on the math. I understand how to calculate a the resistor needed for a series circuit with a power source and several LEDs, but I do not grok the math for parallel circuits. Can all of the parallel series equal the total voltage? Do I just add the amps from all of the LEDs to figure how many series I can run parallel? Or am I completely off track? Thanks for the help!

Topic by karhas 7 years ago  |  last reply 7 years ago


Batterys in parallel and in series? Answered

I am designing a circuit with some space restrictions. Unfortunately i can only put 3 AAA batterys in it. I need at least 1.8 volts for the circuit to be operational, so 2 AAA NiMh batterys in series is rated 2.4 volts. If i have this can i also add a single parallel battery, for added Mah. The diode i will be using has a forward voltage drop of .33v at 1 amp. These batterys will have a load of about 500 Ma. Will the (very bad) schematic i have work? Also, will the output voltage of the batterys be somewhere around 3v? One more question, will the load be shared between the batterys?

Question by astroboy907 8 years ago  |  last reply 8 years ago


Series or Parallel speakers?

Quick question guys. I have two speakers I extracted from a laptop, and I need to use them for an iPod. The loudness is the goal here. So what's best for the volume - attaching them in series or parallel? Does it make a difference? I don't have time to get an amplifier, for it's due tomorrow morning, and I didn't think about using speakers until this morning. Thanks!

Topic by freethetech 7 years ago  |  last reply 7 years ago


parallel light bulbs? Answered

Is there any way of connecting multiple fluorescent light bulbs *THIS* to 1 power plug....i'm a newb, so if this is pretty complicated, i'm gonna need some articles :) the reason i ask this is because i'm thinking about constructing a (full room) black light in it's own sweet casing. it would go around my whole room around the perimeter (around the upper edge, touching the ceiling) so ya...i have enough construction knowledge to build the casing and everything else, BUT i do not know hardly anything about electrical stuff...which is why i have you guys :) so ya...any help (or different solutions other than light bulbs) would be greatly appreciated. thanks :)

Question by miqt 9 years ago  |  last reply 9 years ago


Solar Panels in Parallel? Answered

I know that you can wire solar panels together to combine the amps. But I've only ever seen this done with 2 identical panels. Would there be any problem with wiring up 2 panels with different A values? More specifically these 2 panels. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item;=390312612951&ssPageName;=STRK:MEWNX:IT#ht_10141wt_1165 http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item;=320381449459&ssPageName;=STRK:MEWNX:IT#ht_10175wt_1165

Question by madmanmoe64 7 years ago  |  last reply 7 years ago


cnc smoothrods are not parallel?

Hey guys i am 19 years old and a few of us are trying to make a CNC. well we are planing to use smooth rods for support .well the problem now is when we make the arch for y axis the holes that we made for the smooth rods to go through is not perfectly parallel ,so this resulted in the smooth rods to be slightly non parallel 4-5mm over 1 meter that's the error.Well my IITan friend is so stubborn in saying that this small error will make the carriage to stall. So if there are any experienced personel please clarify this doubt for me, because this error wont matter so much according to my calculations. thank you for looking into the matter

Question by cthaliyath 4 years ago  |  last reply 4 years ago


parallel port input?

Plz help me to, how can i receive signal or instruction from paralel port, how should i send current/signal to its register. what equipment should i need. actually i want to develope a system in c language to control electricity of home, doors or widows, so i need to check that if the door is open or closes. when door closed then computer should indicate me that the door is closed, and same door has opened. sir plz give me guideline. i would be very very thankfull to u. ( simply tell me how current/data/signal can be sent through parallel port, current source, equipment ets, after that i will make sensers for it my self)

Question by 9 years ago  |  last reply 9 years ago


Parallelized Wind Power

This started as a blog post on Make http://blog.makezine.com/archive/2008/05/parallelized_wind_power.htmlIt was suggested to head over to instructables and get some stuff going here and it seemed a good idea. Also, in the meantime I found (of course) a bunch of cool wind projects here (about 20). I really like the vertical Savonius turbines. I wonder if those could be stacked with a similar effect?I've been wanting to do a wind power project for a while, and it seems like a good one to work on with others. Here's a brainstorm to kick things off. Please add to it or suggest alternatives problems etc.- total parts cost < $200- leverage off the shelf parts as much as possible. - little or no machining.- over 100 watts, (ideally 300-500) (this could be totally unrealistic with a $200 price, not sure yet)- usable in small yards, urban roof topsThe guys who made the original did some research for a grant and the paper is available here: http://www.speakerfactory.net/TURBINES/GRANTS/Selsam%20EISG%2002-18%20Final.docAlright. Hopefully this is enough to kick off some discussion and gather up interested parties. I think the first step will be to tack down goals and solidify a general approach. Ideally in the end, we can come up with a good parts list from a minimal number of sources, and an instruction set that's relatively easy. A group might also leverage some purchase power by getting some of these parts in bulk (ie. a whole bunch of airplane props). Tim

Topic by timothy 10 years ago  |  last reply 10 years ago


are these pins for parallel port on my pc's motherboard?? Answered

Take a look at this image there is written PARALLEL and my computer lack prallel ports at the back where it should be with others

Question by Atul009 5 years ago  |  last reply 5 years ago


I need a list of that 5 parallel circuited system that I could make?

If this is possible that would be great!! :)

Question by Roboto12 6 years ago  |  last reply 6 years ago


i want to know power supply requirement of 27 led's in parallel

I am making a 3x3x3 led cube that would b always on(lit up), in such a way that 27 led's will be in parallel, so i want to know how much voltage & current should i give to it. how much voltage & current is requied for 64 led's in parallel ?

Question by rajmaradia 6 years ago  |  last reply 6 years ago


When connecting LED's in parallel is it better for each LED to have a resistor or a single resistor at the start?

I am trying to wire 27 LED's in Parallel so that they can work independently of each other. 

Question by Kaisei13 7 years ago  |  last reply 7 years ago


Could you connect 8, 3.2 volt LED's to a 5 volt power source using parallel? If so, what resistor? Answered

I'm trying to connect 8 3.2 volt Blue LED's to a 5 volt power source for a cube lamp I am making. I've done this a few years back but with red LED's and didn't really know what i was doing. But I just found out that Blue LED's need more power to light up. I have them soldered together in a parallel configuration that i found on instructables https://www.instructables.com/id/LEDs-for-Beginners/step8/Wiring-up-multiple-LEDs-in-parallel/                           but i dont know what resistor to use for them. One website says to connect a 100-ohm resistor to each LED and another says to connect a 10-Ohm to one end. I apologize ahead of time because i'm not very knowledgeable in electronics so if its not too much trouble, could you put it into simple terms. Thank you so much for your time!

Question by wolfsheim_lvr1 8 years ago  |  last reply 8 years ago


LED idea brewing! need affirmation on design/wiring? Answered

So this will be my first LED project and after reading just about all there is to read i think i have it down, but b4 i go out and buy everything i want to consult the PRO's and see if it is right and turn this into a instructable. So if you could take a gander at the attached professional scribbled design and give me some feedback id appreciate it. and to clarify im not sure if im going to run this off of 120v or 12v. Thank you!! IT IS WIRED IN PARALLEL!!!  

Question by ARGMISTER 7 years ago  |  last reply 7 years ago


DC motors as generators in parallel?

Hey guys, im doin a project, ill be using two cordless drill motors with a maximum output of 12v each and unknown amp atm. My question is this: Both the outputs of those two motors will equal 24 volts, but I want 12 volts and increased amperage - this will, for the most part, be used to charge a 12 volt lead acid battery and I dont require the safety police on this one. So, can I take both outputs of the dc motors and wire them in parallel and have a resultant potental 12v maximum? Or will I have to use electrickery?? I have only a novice/intermediate skill in electronics and my parts come from re-using old scrap technology. tx, Sky

Topic by Sky Graham 6 years ago  |  last reply 6 years ago


Controlling LED Strips in Parallel

I'm working on a project with LED strips Namely, these ones using a LPD8806 PWM. I'm using these because I really want the ability to assign each light individually. I was hoping I could hook up an Arduino to do the controlling. My problem is that I need to cut the strip into smaller sections, and then use the sections in different places. I could conceivably wire each smaller section of the strip to the next in series, but it would be easier to just run separate sets of wires to each and have a parallel set up. I'm just concerned that if I do this, the Arduino may not be able to still control each light individually. Thanks for any help! I gotz ta have my color-changing LEDs!

Topic by SteamEngenius 6 years ago  |  last reply 6 years ago


Adding capacitors. Series or parallel? Answered

I was building a curcuit and had no 0.05uf capasitators so I decided to use five 0.01 capastators. Should I wire them in series or parallel? Also they are ceramic. Thanks for any help. David.

Question by David97 7 years ago  |  last reply 7 years ago


Any danger in Parallel battery circuit?

Hi, I have a voice recorder that runs on a 1.5 V AAA battery. I keep running through too many of them. I have more  AA batteries and I was able to figure out a  setup to run it off non-AAA sources. I was thinking of connecting 2 AA in parallel. Is there any danger my recorder if I do that? Any power spikes  or other things that can destroy my recorder?

Question by phillyj 9 years ago  |  last reply 9 years ago


Interfacing a parallel port and L293D motor drive( PWM)?

I have interfaced a L293D directly with the lpt port of my desktop. A java code in the cpu generates an output of either +5 or 0V. There is no other connection between the parallel port and the l293d. These voltages from the lpt are inputs directly to the motor drive, and the motor rotates when the code runs. My question is: Can you perform pulse width modulation, without using a micro controller? Is there a java code that can do this?

Question by gregarious1987 6 years ago  |  last reply 6 years ago


How to connect a diode on parallel solar panel connection? Answered

I am making a foldable solar charger. I will have 3 panels connected in parallel, for a total rating of 5 volts at 1.5 amps. This will connect directly to a USB boosting converter for a maximum output of 5V at 1 amp for charging or powering a USB device. No batteries will be connected. Can I just use a diode on the + wire where it connects to the USB charger or do I really need one on each panel? Thanks for any help!

Question by Stevemills04 5 years ago  |  last reply 5 years ago


need help in " realy interfaced with parallel port " circuit Answered

Hi my friends my teacher  asked us to make ptoject with parallel port I fount this circuit in this site http://jaspreetscodezone.blogspot.com/2008/01/interfacing-relays-using-parallel-port.html and I have some questions about it now he used in the circuit a 12v relay .. while he's getting a 5v from the parallel port input pins in that case he used a 12v power supply * If the relay was a 5v relay .. I wont need to use any external power supply ? and why he is using the IC here ? also in the components there was ( ribbon wires ) are we going to use them between the circuit and the male connector ? another question is how we connect the relay to work as the bulb switch can I use the 120v bulb that we connect it to household and replace its switch with the relay ? finally what can I use to connect the parallel port to my laptop USB ? I know I've asked alot of things but please help me 

Question by CSE251 6 years ago  |  last reply 6 years ago


two different voltages in parallel?

I have two solar cells. one has an output of about 15-20v depending on the light. The other has an output of about 30-40v depending on the light. what will happen if I connect then in parallel? will the lower voltage one subtract voltage of the higher voltage one leaving me with about 15v? Will the amperage still double with both cells in parallel?

Question by carrierpilot1357 9 years ago  |  last reply 3 years ago


Buck Converter for Parallel LED's

So I am trying to make a gift for someone that will include about 100 LEDs. These LEDs have a forward voltage of 1.8-2.2 ( I am going with 2V) and a max continuous forward current of 30mA. The LEDs: http://www.ebay.com/itm/50-10mm-10000mcd-LED-Lamp-Ultra-Bright-Red-Light-DIY-New-/180763201504?pt=LH_DefaultDomain_0&hash;=item2a16538fe0 Now, I want to be able to plug this sign into a wall so I have purchased an AC to DC power adapter that plugs in into a standard 120V AC outlet and supplies 12V with 2A of current. Here it is: http://www.ebay.com/itm/261176168283 I know one way I could make this work is to have multiple series of 6 LEDs, as 6 LEDs in a series would then require 12V. However, it would make this project a LOT easier to have all the LEDs in a parallel circuit, so I can connect one whole side to the positive terminal and one whole side to the negative terminal. I wanted to know if I could do this: Plug the two wires (+ and -) going from the AC to DC adaptor into a Buck Converter set to 2V and wire it to all the LED's via one wire to a bus wire connected to all of the LEDs' negative terminals and same for the positive terminals.  The converter I was looking at: http://www.ebay.com/itm/DC-DC-Buck-Converter-Adjustable-Step-Down-Breadboard-Power-Module-1-25V-36V-5A-/321355701600?pt=LH_DefaultDomain_0&hash;=item4ad24add60 Also, if I place the switch in between the AC to DC power adapter and the buck converter, the converter would only be on when the LED's are on, right? Lastly, would all the LEDs have the same brightness? I know at 2V with 100 LEDs the output would need to be about 3A. Is it okay given that the power adapter supplies 2A but at a higher voltage? As in does the converter convert the electricity to a lower voltage but a higher current?

Topic by soulmouse 5 years ago  |  last reply 5 years ago


Recharging Li-ions in parallel

Hi I am new to rechargeable cells.For my application, I need 2 Li-ion cells (LIR2032) in parallel to increase the capacity. I am using NCP1835B charger IC . Can I use the same IC to charge them while they are in parallel. Is there any extra protection circuitry to be used? What happens if the 2 cells are at different voltages initially ?Will the trickle current bring one of the cells to proper voltage while not affecting the other one?

Topic by anu_11gem 11 years ago  |  last reply 11 years ago


Connect two transformers in parallel? Answered

Hi! I have a question in case someone can help me. I need an AC/AC converter from 120V to 12V for a halogen lamp. The required output is 210W, but I can't find a big enough transformer for this. Is it possible to connect two, 105W output transformers in parallel in order to achieve the desired 210W?

Question by JuanC368 1 year ago  |  last reply 1 year ago


Connect two transformer in parallel? Answered

Hi... I want to know that can we connect two center tap transformers in parallel? both are same rating of 24-0-24v, 5a. I want dual supply (plus, minus 24V) for audio amplifier that I am planning to build. Can someone explain me all the risks, cautions, etc.? (I am new in audio amplification circuits)

Question by SaurIMX 5 years ago  |  last reply 3 years ago


How to parallel 2n3055 transistors? Answered

I am working on an inverter that will be run off a car battery. It will use a ne556 timer to drive the 2n3055 transistors (50-60Hz) I will have in parallel leading to my centre tapped step up transformer which will be a modified microwave oven transformer. My car battery is a 12V 65Ah battery that I will intend to draw about 200Amps from, the car battery will only be run through the transistor and transformer part of the circuit, the driver I will run off a much lesser power source.  Altogether I will be using 50 2n3055 transistors, two groups of 25 for either side of the transformer this will have a potential of 2875 Watts. How can I parallel these transistors to balance them to avoid cascade failure?

Question by The MadScientist 7 years ago  |  last reply 7 years ago


LED Lamp Parallel Circuit

Hello everyone, My first question in this forum to build a LED panel with parallel LED connections. Input:  220V AC Bright White LED 5mm I want to put 36 LED in a panel and want to use bridge connections which will power up both the LED panel and a 12V Battery simultaneously, so when the power goes it will take the power from the battery. Can anyone guide me with circuit? I am novice and have interest to make things like this for own use. Thank You MarlöPax 

Topic by marlopax 8 years ago  |  last reply 8 years ago


can leds do seies?

I know that this is a pretty noobish question but can LEDs be used in series or only in parallel like bulbs?

Topic by NetReaper 10 years ago  |  last reply 10 years ago


How do I wire and power a simple LED circuit?

I'm trying to create a sign with letters made of 40 10mm LED bulbs. They come pre-wired with individual resistors and only say they require 9v-12v at 20mA. Here is a link: http://www.ebay.com/itm/10pcs-10mm-White-Diffused-Round-Pre-Wired-LEDs-Light-9V-12v-USA-/111795082716? I would like to wire them in a parallel circuit. I'm also trying to power a single red LED of the same variety, but have read that because the draw can be different I shouldn't wire it to be the 41st bulb in the parallel circuit. It too comes with its own resistor: http://www.ebay.com/itm/10pcs-10mm-Red-Diffused-Round-Pre-Wired-LEDs-Light-9V-12v-USA-/111844141486hash=item1a0a6e29ae:g:TvUAAOSwFnFWCKU4 I'd like to be able to power these 41 bulbs with a single power source, and integrate a rocker switch to turn the fixture on and off, will I need to a specific switch for this? How should I wire the LEDs? Can I connect the series straight to a 12v power source because each bulb has a resistor? 

Question by JackR124 2 years ago  |  last reply 2 years ago


alkaline batteries connected in parallel, quick question

Okay, doing some throwie-inspired LED "artwork" and I'm using alkaline AA batteries instead of the CR2302s or similar smaller cells to get way more mAh and extend the life of my display. I've got all the proper resistors and AAs connected in series to get the right voltage, etc... but I want to rig up a second set of AAs in parallel. I've found a few posts and websites talking mainly about lithium cells and/or specifically rechargeables connected in parallel, but nothing on alkalines. I know to make sure they're of the same make, type, not to mix new and old (aka the same mA)... but will leaving parallel alkaline batteries connected until they are all used up cause any problems, possible fires, leakage, plagues, end of the world? I've found one web page talking about if one of the cells in parallel was lower in mA (or maybe only if it's faulty?) it could drain faster and possibly short, draining the energy from the other cells, possibly causing a fire hazard... Not good for my artwork or the places it will be displayed. Any thoughts would be greatly appreciated. Thanks for the help!

Topic by shanepollard 10 years ago  |  last reply 9 years ago


Wiring Two Ports on a Phone Battery Bank in Parallel?

If a power bank claims that each port on it can charge a device at 2 amps, if I connect both ports together in parallel, am I able to get 4 amps? Or would it be just like trying to double the voltage off of the same battery, and not work? I have an Intel Compute Stick, which requires 3 amps to run. However, battery banks that provide more than 2.1 amps per port are super rare. Would it work to wire them in parallel?

Question by RocketPenguin 2 years ago  |  last reply 2 years ago


Is it a good idea to wire an ELECTRET mic in parallel? What are the advantages and disadvantages? Answered

I already made a prototype of a low-noise desktop microphone (with an internal 5 stage transistor preamp). It only had one ECM capsule inside. A few days later I found a couple of pictures of a certain microphone with two ECM capsules wired up in parallel. It made me wonder, will it increase the sensitivity of the mic while reducing noise or will do the exact opposite? Is is a bad idea to hook six of these in parallel? Sorry, I'm not an expert when it comes to microphones. Before I post a guide, I wanted to make sure of what I'm saying.  The Reason: If you are familiar with the Blue Snowball USB microphone, you'll be surprised on what's in it. I recently discovered that it has two "Electret Condenser Mic Capsules" soldered in parallel. I thought there was something special about the Snowball since the reviews went crazy (4 1/2 stars on amazon)! I was expecting a huge diaphragm, but no, it only had two tiny ECM mics soldered on a Preamp + USB DAC. Lesson learned! Never underestimate an ECM mic.  ______________________ The picture is my prototype, it's working great right now. Luckily, the 5 stage preamp is giving zero noise. I'm planning to add a USB D.A.C. and an ECM array on my final version.

Question by ASCAS 4 years ago  |  last reply 3 years ago


How can I modify this circuit to sequentially turn on LEDs in parallel, while avoiding voltage drops? Answered

I have a single pole, 12 throw rotary switch which I want to solder to a set of LEDs so that rotating the switch clockwise lights more LEDs as follows: 1 = 1 Red LED 2 = 2 Red LEDs 3 = 3 Red LEDs 4 = 4 Red LEDs 5 = 5 Yellow LEDs 6 = 6 Yellow LEDs 7 = 7 Yellow LEDs 8 = 8 Yellow LEDs 9 = 9 Blue LEDs 10 = 10 Blue LEDs 11 = 11 Blue LEDs 12 = 12 Blue LEDs Since there will be a voltage drop across the diodes, the LEDs at the start of the chain will get progressively dimmer, and increasing the voltage would blow the LEDs in shorter chains. One modification I know I could already make would be to not use the first 4 diodes on the yellow LEDs, and the first 8 diodes on the red LEDs, as a minimum of 5 yellows and 9 blue will be active for each position. This still leaves a maximum of 3 diodes in each chain, which I still think would cause the lights to be much dimmer. Another solution I can think of is to have multiple wires coming from each terminal of the switch, each with their own diode, which would ensure all active LEDs had the same brightness (I'm not sure if this would cause the whole chain to be dimmer than shorter chains or not). The downside is this would need  31 wires rather than 13, and that's only if I bridged together all the shortest LED chains of each sequence: individual wires for absolutely every position would mean 79 wires+diodes). To put this in context, I want to create the health bar from Dead Space 3: If you can suggest a way of improving the circuit, or totally re-designing it, it'd help me loads! Thanks!

Question by Shadow Of Intent 5 years ago  |  last reply 5 years ago


How to show change in current?

I am making a trainer kit for my students. The kit will show the operation of resistors in series and in parallel. In series circuit I connected an LDR with a piezo buzzer which shows the change in voltage. But the same thing does not work in the parallel thing. The change in current does not affect the buzzer. Any Idea what can be done to solve the problem is appreciated?

Question by artworker 7 years ago  |  last reply 7 years ago


Connect USB HP printer to Arduino UNO Answered

Hi, i want to connect a USB printer to an arduino to control it, i know that i can connect a Printer by using the Parallel cable, but my printer only works with usb. Any ideas????

Question by gastonbr100 4 years ago  |  last reply 4 years ago


A lamp from RGB LEDs

Hi, I'm want to build a lamp from 63 RGB LEDs. I want to be able to change the intensity of each color. Is there something in my schematics that should  be changed, for example do I even need the resistors after LEDs since I have the potentiometers. I think the values might need to be changed. The switches before resistors are to eliminate that color if the potentiometers won't do it. There should be also a main switch after the power supply.. Do I need anything else, so that it will work and to it will be safe? A bit offtopic, but if I would only use one color LEDs, would it be better to connect them to parallel or series?

Topic by goljat 5 years ago  |  last reply 5 years ago


charging 10s5p battery pack

I'm working on an ebike conversion. I'm buying laptop batteries to take out the 18650s and put them in my pack. I'm looking at a 10s 37v pcm. If I make it in 10 sets of 6 to get 37v 14.4ah, then how can I safely charge the battery so that they don't charge unevenly in each set?

Topic by leaf26 5 years ago  |  last reply 5 years ago


Arduino code Porting Please Help? Answered

Hi please can someone port this code from lcd - to serial output to pc thanks :)  http://www.thebestcasescenario.com/forum/showthread.php?t=25092 /*Arduino Controlled Voltage Monitor Code by Will Lyon 12/5/2010 Code for project Power House on TBCS http://www.thebestcasescenario.com*/ #include //Initialize the library with the numbers of the interface pins LiquidCrystal lcd(7, 8, 9, 10, 11, 12); void setup() {   lcd.begin(16, 2);                      //Set up the LCD's number of columns and rows   lcd.print("  POWER  HOUSE");           //First line opening message   lcd.setCursor(0, 1);   lcd.print("Desktop Pwr Unit");         //Second line opening message   delay(5000);   lcd.setCursor(0, 1);                   //Clear bottom line   lcd.print("                ");   lcd.setCursor(0,0);   lcd.print(" 3v    5v   12v");          //Update top line readout } void loop() {   lcd.setCursor(0, 1);   float f = analogRead(0) * 4.88 / 1023;   // 3.3 => 9.9   lcd.print(f, 2);                        // print float with two decimals   lcd.setCursor(6, 1);   float g = analogRead(1) * 8.5 / 1023;   // 5.0 => 9.9   lcd.print(g, 2);     lcd.setCursor(11, 1);   float h = analogRead(2) * 17.25 / 1023;  // 12.0 => 25.0   lcd.print(h, 2);   delay(1000); }

Question by Daniel Deacon 7 years ago  |  last reply 7 years ago


How to charge a series parallel array?

Hi, we are building an ice cream cart with a 36v sound system and a 12v led dance floor. We desire to do a series-parallel with six 7.2Ah SLA batteries, for the 36v amplifier. And run two 7.2Ah SLA batteries in parallel for the lights.  I would love to brainstorm on how I can charge all these sla batteries. Can people help? We already own a cheap car charger 2 and 6 amp setting.  I am leaning toward throwing a switch or a few switches to go between 36 and 12 for the amps batteries. HELP!!! Thanks, Tor

Question by torclausen 6 years ago  |  last reply 6 years ago


How many LEDs can a 9 volt battery power in parallel?

Basically what the title says 

Question by Zem 9 years ago  |  last reply 2 years ago


for the 8x8x8 led cube what would i change in the ready made code to make the cube work with a usb to parallel cable?

I have the code for the 8x8x8 led cube from this instructable https://www.instructables.com/id/How-to-build-a-8x8x8-led-cube-English-version/ and am trying to make it work with a usb to parallel cable. I'm using vb 6.0

Question by deanevans 9 years ago  |  last reply 9 years ago


How do you tap into a series battery pack to have the full series voltage AND half pack voltage from 2 parallel taps? Answered

I have a 320V lithium battery pack (100 x 3.2V in series) that I need to tap 160V from to run a couple of heating elements with. The main 320V is needed to run a motor. I was hoping to have the 160V taps in parallel (50 x 3.2V in series x 2 in parallel) to keep the pack at a uniform discharge level while still being able to run the motor at full voltage and at the same time. Is this even possible?  Is there an inexpensive way to do it?

Question by Nashty 8 years ago  |  last reply 8 years ago


Can capacitors be wired in a series? Answered

I am pretty sure a series goes from + to - to + ext. and parallel is grouping all + and all - separately. Is it possible to wire capacitors in a series

Question by jj.inc 8 years ago  |  last reply 8 years ago


Help , electric current from adaptor question

Ok kind of a noob question .. so im running 4 12v dc fans using .28 A current in Parallel with an adaptor that outputs 12V with .3 A current. my question is, will i need to add something (resistor or w/e) to limit the current  so my fans dont fry or will i be ok with nothing?.. i also want the voltage to remain at 12V , because i need them running at full  I searched the forums, couldn't find any specific answer Thanks for your help!! -Chris

Topic by cholborn 7 years ago  |  last reply 7 years ago