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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39 views

Relay for Solar System as Backup Only

Background I'm working on a seismic alert network and seismograph station at my school in Puerto Rico. We're building a solar system for the system to continue running during a potential seismic event....
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2answers
62 views

5v to 12 Power Supply

I have really no idea about electronics. I am trying to provide IR lighting for my night camera that I use with the raspberry Pi. The Pi is powered by a 5v usb power bank. The IR requires 12v. I ...
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1answer
38 views

Running 4.5v LED string from 12v leisure battery

I have a string of 20 LEDs designed to run from 3x AA batteries in series. I plan to hook these up to a 12v leisure battery. Until recently I had always concentrated on getting the voltage right (...
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2answers
76 views

How does one use a transistor connected in either series or parallel with the load in a linear regulated power supply?

Let's say using a transformer and a rectifier to bring the voltage supply to roughly 18 DC (little voltage ripple which solved by using polarised capacitors) and I use a LM7812 regulator to bring down ...
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2answers
51 views

How a little extra current can affect a motor

I want to run a 12V, 19 watts DC motor. Which should use 1.5amp of current. Now, I have a 12v DC, 2 amp power supply adapter. How it will affect the motor in the long term. Will it burn the motor for ...
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1answer
74 views

Modify PCB Mains Voltage input to 12VDC

One of my amplifiers has died so I need to find out if I can hookup a spare I have lying around as per "Section B" of the below block diagram. I have done the same modification before on ...
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2answers
67 views

12 AWG galvanized steel high tensile wire okay for running 12 volt 7 A DC?

I need to run 12 VDC about 50' along a fence that already has several 12 gauge galvanized steel wires running on it. It is going to be pulling less than 7 A at most. I can make sure the lines are not ...
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1answer
19 views

Connecting 2 identical led RGBW controllers with 12V led strips same length into a 24V Power supply [closed]

Ok, some bad decisions took place and now i am stuck with no money and: 24V 8.33A power supply with 2 channels. Magic Home 5V-12V-24V RGBW wifi Controller 192W max (got them from here) 15m of 12V ...
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0answers
35 views

Dual Coil relay driver [closed]

I found the following schematics to drive a dual coil latching relay My questions are: How to adapt that to drive 12v or 24v low coil current PCB relay? and what smd components can I use?
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0answers
66 views

MOSFET as PWR/GND DPST Switch

I have started trying to replace relays in my (12V) electrical circuits with MOSFETs. I have somewhat limited experience with MOSFETs, but I think I'm starting to understand it more. I've drawn a ...
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0answers
28 views

Is it safe/possible to add a BMS board to a soft pack 3s1p LIPO for charging and discharging?

i would like to make a 12V battery pack from a soft pack LiPo which can supply 10A for my projects which i can charge from a 12.6V DC wall powersupply. I dont want to use an external big special BMS ...
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2answers
136 views

Way to calculate the dangerousness level of volts+amps? (don't want to learn the hard way) [duplicate]

Is there a formula to calculate the dangerousness of amps, and volts? like watts, for example. Watts = Volts x Amps. Generally speaking, you could say wattage takes into account volts, and amps. I am ...
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1answer
56 views

Switch 12V with 3V control circuit

Edit: I did a dumb-dumb. I got the emitter and collector mixed up on both transistors. Now it works. What I'm trying to accomplish: I'm planning to run a ESP8266 microcontroller in my car. The ESP ...
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90 views

Powering two 19v devices from a single 12V to 19V converter

I am building a laptop charger to run off of a 12V source (lithium batteries in a camper). Initially, I was just going to replicate this article to make a 12V MagSafe 2 charger for my MacBook Pro (up ...
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1answer
70 views

Generating +65 V (positive) and -65 V (negative) voltages from two 12 V batteries using cheap step-up converters?

I need to power a 300 W class D amplifier with positive and negative 65 V. As I'm a do-it-yourself guy, I didn't know about positive and negative voltage and ordered a bunch of these normal step-up ...
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1answer
43 views

Using a 50mA switch on a 2 amp load

Let me preface by saying I'm a total noob at all of this and just learning as I go via the internet. I'm working on a home project where I need to trigger a submersible pump. I needed the switch for ...
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1answer
29 views

How to run a car radiator with a PC 450w SMPS?

I have a car radiator fan which when measured with a multimeter on a 12v car battery draws 4.7a. I've been trying to run it off an old PC SMPS which is rated at 450W with max amperage of 18a at 12v. ...
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1answer
59 views

Replacing BD139 for TIP122 - Cooler speed control circuit

I'm using a cooler (=fan) to conduct heated air through a hose to a closed chamber using an Arduino UNO PWM . A PID system controls the current across an array of resistors to target the setpoint ...
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4answers
52 views

Current rating for 12v plug on 300W in-car inverter

I have an in-car inverter which is rated 300W. This is the only labeling: I need to source a 12V cigarette socket plug to connect to the input. I have found the following one which is labled: ...
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1answer
49 views

can atx power supply the intel nuc and egpu [closed]

So I want to power my Nuc (mini-pc) with ATX psu and the reason is I built my own egpu(external graphic card) and i would like to throw the nuc in there powered by the same psu that runs the egpu ...
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1answer
75 views

Value of resistor to limit current to 1 ampere in 12 volts circuit

I want to connect my modem directly to a 12volt battery so that I dont need a adapter. My modem’s specs says that it need 12 volt 1 ampere as input.Now the voltage of 12 volts can be directly given by ...
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0answers
12 views

wifi led landscape lights

i'm wanting to add an led strip to my 12v ac landscape lighting. The wifi controller says 5-28v dc input. Do i need to convert from ac to dc and do i need to reduce the amps? this is new to me but am ...
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2answers
102 views

Charging 12V batteries in series and parallel

My question is simply: can 12V lead acid batteries be charged in a "mixed" fashion? By that I mean a situation where a number of them are connected in both series and parallel? This is best explained ...
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2answers
142 views

Need a circuit to detect if something has gone from off-on or on-off

I'm new to circuit design but I'm trying to design a circuit for a power antenna that will send a 5 second pulse whenever it detects a a wire has gone from off-on or on-off. So far I have designed ...
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1answer
67 views

12v wiring regulations (UK)?

What regulations (if any) do I need to follow if wiring a 12 volt system (in the UK). I was planning to wire up a garden shed / summer house to the 220v mains. I'm confident I could wire it safely ...
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1answer
29 views

Internal battery recommendation for a Goal Zero 1000 [closed]

I have a Goal Zero 1000 and the internal battery is dead. I tried with customer service and with the page but they don't have any option and don't have a battery to buy as a replacement. The internal ...
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1answer
35 views

UART single-wire half-duplex level conversion

I have a single-line transmission device, I use the oscilloscope to check the waveform Always keep high potential (12V) and low potential (0V), change to logic analyzer test and find that it can be ...
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2answers
61 views

12V DC To Household power

I have a 12V DC mini air compressor that has a cigarette lighter fitting, now I want to use it for an airbrush kit, can I someway attach a wall plug and use it that way, please excuse my ignorance of ...
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1answer
43 views

Want to vary speed on 12 volt DC RV ceiling fan

I have a 700 cm 12 volt DC RV ceiling fan that can work using my 12 volt DC solar power system. I want to figure out a way to vary the speed of the fan.
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3answers
79 views

Robust low battery cutoff

I am building a 5V DC charger for an offroad motorbike. The main goal is to use this to charge/power a mobile device/phone/tablet whilst travelling/camping. If space allows maybe also a GPS tracker ...
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3answers
981 views

Can you run low voltage current through galvanized steel suspension cable?

The fact that I can find hardly anything about running current through galvanized steel suspension cables on Google should probably tell me I shouldn’t do it, but I thought I’d ask here anyway. I’m ...
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1answer
37 views

Odd problem with PSU [closed]

I don't know a much about electronics so please if you choose to help, layman terms would be appreciated. I have an old 550w PC PSU. I have used it previously with an electronic air pump to pump up ...
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1answer
25 views

Need to run a 75mmx30mm 12v .24a blower for 10 sec

Hey I am very new so I appreciate any help here I am trying to run this small blower off a computer or 3D printer. it’s a 75mmx30mm 12v .24A I need to have it turn on and run for anywhere from 6-8 ...
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3answers
86 views

Solar panel voltage drop [closed]

I'm having a problem with my solar panels. I'm running a gecko 57l fridge out of a 100ah deep cycle battery with an 160w portable solar panels. The system works fine and it outputs 13.7v to charge the ...
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2answers
73 views

Step down transformer alternatives

Does anyone know if I can use a Quam TBL 25 volt 4 watt audio transformer to step down 120 volts to 12 volts, later to be rectified to a 12 volt dc power supply? I know 12 volt power supplys are ...
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2answers
86 views

How to make a continuous current from a flashing source? [closed]

I have a machine running, when a problem occurs, it stops and sends a 12VDC light bulb flashing every second or so, how can I get a constant signal from it to use this signal in the VFD to perform a ...
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0answers
31 views

24v from 2x 12v DC power supply?

I have a box full of 1-6amp 12v power supply and 1 short run of 24v led strip, rated about 1.5amp draw at full blast. Can I take 2x 2A 12v supplies (ungrounded plug) to run in series to easily ...
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2answers
51 views

Can i step up a usb power oulet in my RV to power my cellular signal booster? [closed]

I have an RV with a 12V power system that has usb outlets to provide power for small devices. I have a cellular signal booster that I want to power off one of the usb outlets. The power cord is ...
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1answer
46 views

Reversing the input of a transistor

I want to detect if a 12V DC line has power or not. I want the transistor to work like this: If pin 2 has 5-12V, pin 1 and 3 should be disconnected and should stop the flow of 5V 2A across pin 1 and 3....
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1answer
78 views

What is the power consumption of a 12V adapter running 4 CPU fans?

I have a quick question here. I am not a ECE guy and just a hobbyist trying to tinker while quarantined. I have 4 CPU fans (120mm) laying around and I'm trying to re-purpose them as a small fan. ...
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1answer
28 views

12 V DC Li battery voltage regulation question

I recently bought a 12 V 50 Ah Li battery with the intent to use it for a 12 V DC trolling motor for a boat. The trolling motor runs at up to 30 A. I have read that lithium batteries tend to output ...
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1answer
35 views

Can I run 12V camper van fridge whilst 'trickle charging' the battery in van?

I am running the following setup in my camper van and would like to know if there is a simple solution or device that would be effective in allowing me to run my 12V fridge whilst the leisure battery ...
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2answers
56 views

Wiring 12V lights with shared wires

currently I'm wiring my converted RV. I've a 12V system and want to connect 12V LED lights. I don't want to use RV or rocker switches. I bought standard house light switches. After a lot of research I ...
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2answers
92 views

Can 12V relay be used instead of 5V relays?

I have the project of making a touch switch using the IRFZ44N MOSFET for making a small led glow and stop glowing when I touch the probes. I thought of using a relay if I have to make a bulb glow, by ...
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0answers
21 views

Getting loud whine on dual 12v 80 watt DC Universal radiator fans, especially in reverse

In an effort to create airflow in my studio that has the only window facing a sealed alley, I swapped the AC fans from the useless Holmes dual window fan and replaced them with two 10-inch 12V DC 80-...
2
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1answer
63 views

How do I wire up a 2.3-3 V LED to a 12 V car battery that can have a variable voltage depending if the engine is running or not?

I am making a wireless switch for my car tyre inflator. I have a basic hand-drawn sketch of what I intend to wire up. Basically, it will be a box with an 50 amp Anderson plug for input (right hand ...
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1answer
73 views

Is a short circutied battery (I believe) worth anything? [closed]

While trying to install 2 Duracell Ultra 12V 46Ah AGM batteries to power a trolling motor in a boat, I accidentally connected my wrench from the positive of one battery to the negative of the other. ...
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0answers
56 views

Battery management for 12-24V motors

We have 4 12-24V motors which we want to connect to a 14,8V battery. Two of the motors are position controlled (M3 and M4, see figure) and will not draw much current as they will mainly be stationary. ...
0
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1answer
69 views

Connecting Three 12V DC Water pumps to the same power source

I am new to all this and I am sure this is a very basic question, but wanted to ask before I fry some pumps up. I have a relay, which is controlled by my raspberry pi, switching the pump on and off. ...
0
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2answers
41 views

Calculation of max possible current load from voltage multiplier connected to PSU 12V rail [closed]

today I found in a box a PSU with two 12V rails each delivering 17A (Fortron SAGA II 400W) and decided to step-up the voltage so can feed the DPS5020-USB DC-DC converter (rated at 60V/20A max output). ...

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