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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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1answer
35 views

Particle Argon controlling 12V, using 3.7V LiPo

I am trying to control a 12V DC motor using a Particle Argon, powered by a 3.7V LiPo. To get 12V I am using this step up regulator, and to control the motor I am using this DC motor controller. I am ...
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0answers
22 views

Variable voltage relay (Open 10v and below, Closed 12v and above)

I need to trigger (close) a relay when my circuit voltage goes from 9v to 12v. Trying to keep this simple but fear that the voltage difference is too small for relay to open when voltage drops to 9v. ...
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0answers
23 views

Raspberry Pi + L293D to switch 12V solenoid valves

I am porting an Arduino project to Raspberry Pi. On the Arduino I switched two 12V solenoid Valves with the help of a L293D IC. It worked perfectly. Now I am porting this system to a Raspberry Pi. ...
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1answer
63 views

LED Lightbar as a turn signal [closed]

I changed my turn signals to LED light bars the other day. They are completely legal, but the issue I'm having is I can't use my parking lights and turn signals. The bulb that I took out and replaced ...
6
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3answers
829 views

Discharge time of 12 V 8.4 Ah at 5 mA

I have a motorcycle battery rated as 8.4 Ah (20 HR). It also says 8 Ah (10 HR) and I am not sure what the difference is. Anyway, I have a GPS tracker fitted with a rated ...
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1answer
49 views

Polarity. What do “C” & “P” signify?

G4 bi pin LED bulb. Silicone coated Hello all. Thanks for the forum. I have some of these: G4 bi pin LED bulbs. Silicone coated dimmable 12 volt DC. They are 1.5watt. Although not visible on this ...
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1answer
47 views

How to control a lightbar with 20 individual modules? [closed]

The TL;DR version of my question is, how do you control 20 pieces of 12V/1A outputs in the most reliable, compact and cost efficient way, with something programmable? The long version: I got a ...
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1answer
74 views

12v relay latching until no power [duplicate]

So I'm awaiting to wire in one or two relays so that a circuit is not powered until a push button is pressed. Then the circuit remains powered until total power is turned off. I've been trying to ...
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0answers
69 views

Boat wiring mystery puzzle

First post, please forgive any errors. Our dear father passed away leaving us his boat. The owner before had made some changes to the wiring (not for the better) leaving a tangle of loose ends and ...
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1answer
34 views

12 V 3.8 A water pump to 12 V 625CCA battery

Wanting to use car battery to power pump. Pump says it's 12 V 3.8 A, uses a 8 A fuse. Trying to sort out possible solar input needed to run pump but the numbers don't make sense. What size solar panel ...
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1answer
18 views

Dimming LED with speed controller

I'm trying to controll 4 parallel 12V DC LED strips with an speedcontroller. I am able to dim the lights from 100% lit to about 5% lit, but it never turns them off completely. My multimeter can't ...
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votes
8answers
2k views

Using a 12 V 3 A bilge pump on a 12 V 8.5 A LED power supply

I recently bought the following for a grey water system project I'm working on: 3 x 12 V, 3 A bilge pumps 1 x 12 V 12.5 A power supply I'm not an electronics expert, so my assumption was that the ...
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1answer
37 views

Diodes needed (parts) for OR gate automotive relay circuit

I need to power up a make-or-break simple automotive relay (4pin, 40A 12V) via an OR gate. OR gate as follows: Source 1 is the car dome light which I will tap into and source 2 is engine-on port ...
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votes
1answer
51 views

Check for 12V with Arduino (Two resistors and a diode)

I need to read the presence of 12V on one of the lines of the board. I want to read using Arduino UNO. I found the following scheme: Is this scheme correct?
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5answers
167 views

Soft start for fridge compresser

I live in an off grid property running on 6 12v batteries. We have a 2000w inverter and are trying to get a fridge to run on our system. We have enough power to run it however the issue I am having is ...
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3answers
50 views

Does a plugged in 12v usb-charger use energy when no device is connected?

I hard-wired a 12v cigarette-plug into my a-pillar. The whole point is to have an additional phone charger on the leftside where my phone mostly sits. I connected it directly to the battery ( with a ...
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4answers
98 views

Do I need a relay for my LED bars?

I installed two 4" 18 watt LED light bars on my ATV. It is currently wired to the factory switch on the ATV handlebars and there is no relay being used. I have had to replace the right LED bar twice ...
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1answer
40 views

Need some assistance with making a battery box

I recently bought a 12v deep cycle battery 75 AH and I made a battery box following these tutorials: https://www.youtube.com/watch?v=cAErwLnsSIY and https://www.youtube.com/watch?v=torSEtjPZ2I (no ...
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votes
1answer
98 views

Should I Use a diode for this application? [closed]

I am trying to run a small 12v motor from the same battery. One source is a timer the other a remote. The timer does not function when both are hooked up to the motor. I’m assuming it is from feedback....
0
votes
1answer
41 views

DC Battery Stability

I have a 12 V load that works by connecting an adapter from the AC socket and this adapter output 12v to the load. I decided to make a 12 v battery that can charged and the feed this load , all the ...
0
votes
1answer
34 views

How to protect against a short circuit fail in 12VDC X capacitor?

When adding an X capacitor for simple line filtering in a 12V DC electronics project, how would you add protection against an unlikely short circuit failure in that capacitor? Is it as simple as a ...
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1answer
38 views

How to deal with an inconsistent / noisy power signal?

I'm using a 12v power supply to operate a system of sensors that is very sensitive to fluctuations in the voltage input. Unfortunately, I can't control what goes on upstream of my components and this ...
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2answers
49 views

Decrease voltage in circuit

If I have 90 VDC 3.5 A, and I want to reduce to 12 volt, in excellent efficient the amps will be around 25 A. Can I use a 12 V L7812 regulator?
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2answers
113 views

Is there such a switch?

I am looking for a single 12V DC switch which has an on-off-on actuator that will do the following: two 12 volt+ input pins completely separate from each other, each with its own two loads. In other ...
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2answers
61 views

Tachometer Signal Voltage Reduction

I am working on a formula style car and creating a digital dash based on an Arduino. I currently have a signal from the ECU running at 12v DC and a varied frequency depending on the RPM of the engine. ...
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2answers
85 views

Is my 12v lead acid battery 100% dead?

so I got a ups with a 12v lead acid battery that was constantly on so the water inside the cells has disappeared, initially the reading voltage was 0.3v, and when I added distilled water it generally ...
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vote
2answers
95 views

make LED 12v light fixtures

I would like to remove the n27 sockets from household light fixtures and replace them with LED lights used in the automotive industry. I would like to put a reasonable amount of LEDs in the fixture to ...
0
votes
1answer
24 views

Charging rate for deep cycle 12v battery

I have a 75 AH deep cycle battery(AGM) and I have a battery charger with 2 modes, 5.5A for car, 2A for motorcycle, as far as I remember, lower charging rate is usually better for longer battery life ...
0
votes
1answer
134 views

Switch on a 10 A circuit with only a 20 mA signal

I'm attempting to wire in a 12 V fan to my car that draws 7 A at full speed. The fan is a fused link directly to the battery. I have a 12 V 20 mA signal wire, but that doesn't appear to be strong ...
0
votes
1answer
26 views

LM2940, 7808 and Multichannel PWM chip

I'm putting together a circuit board to power and dim 5 LED channels. The average voltages on the channels are 12.3V, 11V, 11.4V, 7.8V, 6.6V, and max current is 1A. So my current plan is: 12V ...
0
votes
1answer
68 views

How can I power a USB cord from a 12v 2a power supply?

I'm new to the forums and have a problem I cannot find an answer to. I am making a lamp with LED strips inside powered by a 12v 2a power supply. I want to also power a USB cord with this power ...
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1answer
45 views

PC power supply for 12v 24A consumer, question on 12v yellow wires

I want to buy and convert a 350W PC power supply into a 12v power supply for 20m RGBW led strips. I want to do this because I did not find any reasonable priced 12v power supply and simply because I ...
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1answer
40 views

12V battery charging inside caravan

Can I use the 12 V power in caravan to drive for example the lights, whilst the battery is being charged by a mains power charger? By the way, The 12 V system is on a separate circuit to mains power. ...
1
vote
1answer
111 views

What do I need for a portable 12V deep cycle battery?

I'm going to buy a 75 Ah 12V deep cycle battery soon, and I'll need to use it as a portable 12V power supply. The build should be quite simple, but I'd like to ask a few questions to make sure I'm ...
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2answers
66 views

Can I switch two 12v sources with 5 pin relay?

I'm installing a stereo in an RV and would like to maintain default behavior of having the stereo receive power on vehicle accessory power/ignition, but also be controlled by a switch in the RV for ...
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votes
1answer
94 views

12/24VDC to 240VDC Circuit For a UPS

I need to build a circuit to step-up 12vdc or 24vdc to 240vdc and have a current rating of at least 50A. I got this really expensive UPS from someone but it takes a 240v battery pack which I don't ...
0
votes
1answer
113 views

How much input voltage is required to get 12v from LM2596?

I am trying to run WiFi router from a 12v lead acid ups battery. To get a stable 12v output from the battery I used LM2596. Problem is output is always 8.28v-8.50v. No matter how many times I spin ...
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1answer
87 views

Power Supply wiring check

I'm not too confident with electronics and I'm currently working on a project where I need a 12V mains power supply. I got a switch for it and have wired it. I've shown pictures. Is this wiring ...
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1answer
52 views

Car 12V Supplied device - Requirements

I am currently designing a device that is intended to be used outside the car and supplied by car 12V socket (also during the drive). The question is: Are there any specific requirements for example ...
0
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1answer
45 views

Grounding house battery to vehicle chassis

For a solar power installation in a van/RV, should the negative terminal of the house battery —the battery that is charged by the solar panel and used to power devices and appliances whether or not ...
1
vote
1answer
87 views

Arduino and car's 12V switch

I'm trying to control my headlights with my Arduino and a LDR. For this I will use the Arduino as a middle man between the lights switch and the actual lights. The switch has three positions OFF / ...
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3answers
120 views

Can a 12V power supply provide more than the rated current at lower voltages?

This might be a silly question but if I'm using a 12V power supply rated to provide 5A does that mean that if I was to regulate the voltage down to 5V I could theoretically draw 12A at 5V? If Watt = ...
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2answers
99 views

How come no voltage is meassured across my electrolysis tank?

I've built myself a electrolysis tank, using a plastic barrel as the container, rebar as the sacrificial cathode, a 12v 15A car charger (DC), and a Sodium Carbonate solutions as the eletrolyte. The ...
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votes
1answer
68 views

Which connector type is this?

I'm looking for the bullet type connector that is used with Tracer Power batteries. Here's the link for their version of it: https://www.tracerpower.com/bullet-bare-ends.html I found a connector ...
2
votes
1answer
57 views

How to wire a relay for 12v car lighting

I would like to reconfigure the current wiring of my daytime running lights. The relay is currently switched on via an accessory power wire with inline switch. I would prefer the relay to turn the ...
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votes
2answers
64 views

Determining minimum safe wire width at high amps in a DC 12V system

In a 12V DC system, given a particular maximum current and length of wire, what is the best method to determine the minimum width (gauge) of that wire? In particular, what method is best for high ...
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1answer
86 views

Alternative to relay (switching 12V with 12V accesory in car)

What are the other alternatives to relay would be for switching 12V battery power rail with accesory (ignition) power? I'm trying to find an alternative, because the relay is too big for my ...
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2answers
109 views

Need help building circuit for 5V-12V Voltage regulation of external 12V power-source via PWM-GPIO of Raspberry Pi

I have a project, where a raspberry-pi shall measure temperature, and regulate a 12V non-pwm fan by modifying voltage throughput to the fan between 5V and 12V. The fan has a separate power-supply. ...
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4answers
85 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 ...
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1answer
139 views

micro blown up with 3V?

I'm attempting to make a 12v blinking light that turns off with a high signal and since I've got some 5v arduino pro minis I though I might do it with them. So I put together a program and a plan My ...