Questions tagged [12v]

Questions relating systems powered by a 12 volt supply. This may include automotive systems and lead-acid batteries that are nominally 12 volts although be aware that under many conditions the actual voltage may be several volts higher.

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6
votes
3answers
16k views

Detect car +12V using Arduino

I am looking to detect 12+V from a car wire using an Arduino. I have found the following schematic: I know how crazy automotive voltage can get so I just want to make sure the schematic I found ...
20
votes
3answers
81k views

How to transform 5V into 12V?

I would like to transform 5V 500mA (from USB power) into 12V with a few cheap components. Is this possible with the help of some generic parts (and not with the help of some expensive transformer, ...
7
votes
2answers
6k views

Arduino Uno with 12V pump: transistor or optocoupler+12V relay?

I'm not a real expert in electronics but I'm going to start a new project that has completely captured me. I need to drive a 12V pump with my Arduino Uno. The pump is "Dp0102" (12V, 0.7A). To power ...
3
votes
0answers
118 views

How can i transfer 12 V, 50 Hz, 1 A wirelessly? [closed]

I want to transfer electical power wirelessly from a transmitter to a receiver coil. Input energy is provided by a single phase step-down transformer - 230V/12V AC, 50 Hz, 1,000 mA. Using the 12 V ...
1
vote
3answers
7k views

Powering 12V device from 5/9/12V powerbank [closed]

I recently bought the Litionite Falcon powerbank that has one of its outs designed for 5/9/12V. The 12V is at 1.5A which I thought would be enough for my 12V/0.8A camera. However, connecting the ...
42
votes
8answers
79k views

Can a 12V battery give you a shock or not?

I am reading a book called "Make: Electronics" and, on page 9, it says: "Anyone who has dropped an adjustable wrench across the bare terminals of a car battery will tell you that short circuits can ...
0
votes
1answer
3k views

Relay circuit with off switch

I've been searching for a similar circuit and only found latching relays with two momentary switches for on and off. I don't know if this circuit has a specific name or not, and since I am a complete ...
2
votes
5answers
6k views

Why does my DIY “solar panel circuit” show battery voltage and not solar panel voltage?

I've got two solar panels set up in series as shown on the below schema. I connect positive on panel A to positive on battery, and negative on panel B to negative on battery. The two panels produce 9V ...
14
votes
3answers
76k views

Using a 12V battery while simultaneously charging via solar panel

I have a couple of 12v batteries that I'd like to use to power a cooling apparatus while camping for several days. I also have a 15W solar panel I'd like to use to top-off the battery. Can I use the ...
19
votes
3answers
4k views

Explain the logic of a 12 V to 9 V conversion

How does the below circuit work? I know what resistors, capacitors, and transistors do and have played with them on a microcontroller board, but am I trying to understand the logic of the circuit. I ...
9
votes
3answers
18k views

Switching 12V with an active low 5V signal

I’m trying to switch 12V (max 30mA) with a signal from a MCU that I’d prefer to be active low (so the output voltage is 12V when the control signal is 0V, and 0V when the control signal is 5V). Since ...
3
votes
2answers
5k views

Relay for Intermittent Wiper Function

I want to add an intermittent function to the wipers on my 40-year-old car without any additional switches. The details of the wipers can be found here [http://www.globalsoftware-inc.com/coolerman/...
7
votes
3answers
2k views

DIY 12 Volt UPS

Hi i am trying to make a UPS for a project that requires 12Volts. I'm currently using a replay diode and capacitor. My problem is that when the switchover occurs, the voltage drops from 12Volts to ...
6
votes
2answers
29k views

How can I safely charge 3 lithium 18650 batteries to use in one pack?

I'm working on a project to make my own super-bright bike taillight using an emergency flasher LED (something like this:) The LED package requires a 12V input, but from what I've read from other ...
3
votes
3answers
2k views

Data over power line in a car

I am trying to build a communications system for a car, for turning gadgets on or off. One idea was to parasite on power lines, but what kind of components and signaling could be used for this? I am ...
2
votes
4answers
5k views

Using relays to switch between video outputs

I have a simple question: would I be able to send a video signal (composite) to each relay per camera? The reason is that I only have one video input but need to be able to use two cameras (not at the ...
1
vote
1answer
66 views

Can multiple window blind motors run on the same low voltage wire?

I have a wall of 8 windows using battery operated motors (8 AA batteries in a long tube). I am looking to run these off a DC power supply instead. I can't get the exact specs on the motors, but a ...
1
vote
2answers
134 views

First Time Using Integrated Circuits

I am building a circuit for a custom application. I have an old Toyota truck, and I keep leaving the headlights on, because there is no warning buzzer! I have designed a circuit that takes 3 inputs: *...
4
votes
2answers
43k views

How long will it take to completely run out of power for two A23 batties(12volt each) on a serial circuit with 6 leds?

I'm connecting 6 LEDs serially with two 12volt batteries. Each LED needs 3.2 volt and takes 20mA of current. I'm using two alkaline max 12 volt batteries(A23 LR23) and ATC is their manufacturer. I ...
4
votes
2answers
7k views

Generating 12V PWM from 5V PWM

I am generating a 5V PWM signal from my MCU (an Atmel ATMEGA1284P). I need to convert this to a 12V PWM signal. For this I designed the circuit below, something very similar to a Sziklai pair, but ...
3
votes
1answer
2k views

Setting D+ D- ports to set 12V From Qualcomm QC Chargers

I have a Qualcomm charger that I would like to output a constant 12V/ 20V. I know phones and tablets that support QC protocols set D+ and D- for different voltages (as in picture below). I'm wondering ...
3
votes
2answers
3k views

Can I get 24V from ATX PSU using 12V and -12V cables?

ATX PSU's have one -12V cable, and a few 12V yellow ones. Could I power up a 24V device by connecting 12V to + on the device and -12V on -?
3
votes
1answer
13k views

Clean 12v car power

I am looking to get a constant, clean 12V from my cars 12V line. I am wondering if all I am in need of to pull this off would be a simple 12V fixed regulator? The 12V would be hooked up to a pico ...
3
votes
3answers
2k views

draw 30W @ 5v to run LED light string and Arduino from a car battery?

I've got a set of LPD6803 LED lights controlled by an Arduino that I'd like to connect to a 12v system powered off an auto battery. The lights can run off 5-12V but this particular Arduino board is ...
2
votes
4answers
220 views

Analog Audio Signal over dedicated Ethernet/Twisted Pair Cable

I need to send an audio signal over 3 meters and back again on the same line (the plan is to put an on/off switch and a volume regulator at the end of the line). Additionally I would like to send 12 ...
2
votes
1answer
850 views

Lead Acid Battery charging from laptop psu

I working on a new project of running couple of low power devices from PicoUPS 120 ATV: The review by this guy: Building a 12V DC UPS Is this correct, this does not regulate the output voltage, the ...
1
vote
2answers
2k views

How to use arduino and P-channel & N-channel MOSFET to control voltage to PT2264 address pins

Im looking to control a PT2264 RF transmitter module from an arduino so that I can transmit to different receivers. To do this I need to supply either +12v or 0v to the various address pins of the ...
1
vote
4answers
35k views

How to connect a Inductive Proximity Sensor Switch NPN DC6-36V to PIC18F4550 5V

I have got a LJ12A3-4-Z/BX Inductive Proximity Sensor Switch NPN DC6-36V with this Specifications: Model: LJ12A3-4-Z/BX Theory: Inductive Type Sensor Wire Type: Cylindrical DC 3 Wire Type ...
1
vote
4answers
6k views

12V solenoid drawing more current than it needs

I'm fairly new to practical electronics so I apologize if any of this is obvious. I am currently trying to use a microcontroller to control the energizing of several 12V solenoid valves using a PC ...
1
vote
2answers
1k views

Cuttable 12V LED strip

I'm building a computer, and I want to add LED lighting to the case. However, here in Finland, LED strips are too expensive, and I found this: http://www.tinydeal.com/15w-360lm-6000k-60cm-12v-...
1
vote
1answer
2k views

Powering a 4-Pin stock CPU heatsink fan with an external power supply

I have scoured this website and the rest of the internet looking for a solution to my particular issue, but as of yet I have not found an answer. If this is a duplicate question I am sincerely sorry, ...
1
vote
2answers
2k views

UPS 12V power switching

I was trying to make a sort of UPS circuit with a 12V DC 5Ah power supply and a 12V 5Ah seal-lead battery. My question is that I don't know how to switch quickly from line supply to battery. I've ...
0
votes
1answer
2k views

How to amplify 3.3v to 12v (PIR and led strip light)

First off this is very similar to what I need to do How to amplify 3.3 volts to 8-9v? I have a 12v power source PIR and 12v led strip lights, This is the specs for the PIR. I want to cut the leds ...
0
votes
1answer
65 views

12V - How to activate an electric item if battery is full

I have a solar system 12V connected to a PWM controller 20A and a lead-acid battery 80Ah deep cycle. What kind of setup should I make to activate a pump (12V) if the battery is full ( >13.8V ) ?
0
votes
1answer
620 views

Can I recharge 12V batteries individually while why are attached in series? [duplicate]

Possible Duplicate: Charging two lead-acid batteries connected in series, separately (with two solar panels) I have 12V Solar Panels and 12V batteries. But my laptop needs 17V to recharge. I ...
0
votes
2answers
1k views

Inverter Design - What DC input voltage for most efficient DC to 120VAC inverter

I have seen several online circuit diagrams for a DC to AC inverter. Commonly many inverters use a transformer to step up 12V to 120V. I understand that inverting from DC to AC requires additional ...
0
votes
2answers
564 views

12 volt switched by 5 volt

I have an issue with 12 volt DC LEDs installed on a 5 volt DC circuit. Switching must be performed as close to instantaneous as possible. So I searched around but nothing would do what I need. I ...
0
votes
2answers
1k views

Quick release connectors - 2 poles, max 1.5kW 12V DC?

What quick release connectors are good for connecting 2 pairs of wires? 2 poles Max 1.5kW 12V DC? (optional) Splashproof
0
votes
3answers
214 views

12VDC to 3 Phase 400V

In order top prevent my seldom used deep well pump (3 Phase, 400V) I plan to daily spin it up for a few seconds. Where the pump is located, the is no power supply (I operate the pump using a ...