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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-4
votes
1answer
40 views

How long will my battery last and how to calculate it? [duplicate]

I have a 12V 18Ah battery I wish to run through a boost converter at 40v and 2.5A to power a 100w led. Could someone figure out how long my battery would power my led and show the ...
-2
votes
1answer
35 views

for 12V 4 leds are not glowing

FOR 12v 4 LEDS ARE NOT GLOWING. LAST ONE IS GOING PROBLEM. AFTER USING VOLTAGE DIVIDING NETWORK ALSO leds droping voltage is 6V,3V,3V,1V simultennisly. so last one not glowing. please tell me the ...
-3
votes
0answers
32 views

for 12V 3V LEDS 4 NUMBERS [on hold]

Circuit is this. first time i connected this only leds. first led is drawing around 6V 2 & 3 leds around 3V so last one not glowing. after i used voltage dividing circuit that is 4 equal ...
-3
votes
1answer
49 views

How to power 12V LED Strip with 5V USB via Computer Mouse Controller?

I'm a electrical idiot, really appreciate it if you could explain in layman terms. I want to use the mouse electrical board, to power and control colours of my LED strip. This is for the chassis and ...
-4
votes
1answer
53 views

Electronics circuit [on hold]

I have 2 batteries AA it provides 3.3 v I amplified the Voltage to 12 V , however the batteries has low current so I need to get 1A , thus am going to use RC circuit so it provides 1A , I need to make ...
2
votes
1answer
68 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 ...
0
votes
1answer
62 views

Need help choosing options for 12V supply from a Lithium-Ion battery

There are lots of Class D audio amplifier modules for 12V use that are both readily available and inexpensive, intended for automotive use (hence the 12V rating). I would like to use one of these, ...
0
votes
0answers
47 views

Disabling OBD2-Interface in a car [migrated]

If a car-thief wants to steal a modern car, he often uses the OBD2 (On Board diagnosis) to "hack" the car. Simplified: He achieves this by plugging his "hacking device" in the port, which aquieres ...
0
votes
3answers
90 views

How do I turn on a magnetic lock with an Arduino?

I have a 12v magnetic lock, which is just an electromagnet. I want to turn it on with my Arduino. I've been able to turn on/off a 5v motor with the Arduino. So I'm guessing the wiring is similar. The ...
0
votes
1answer
36 views

LM2940CT-12 output measuring 9.6V when relay used

So I've got a 12V pump, and a car battery, and I'm trying to regulate the 12-14V from the car battery to 12V output. When using just the LM2940CT-12, it outputs 12V on the dot. But when I use an ...
-1
votes
0answers
36 views

how to control a 12v dc wiper motor with raspberry pi?

I am going to use raspberry Pi for the first time and am looking forward to any suggestions which describes whether a raspberry pi can be used for controlling a 12v Dc wiper motor or not. If yes, how? ...
0
votes
1answer
84 views

Running a 24V motor on a 12V boat system

I'm trying to design a jigging machine for a fishing boat, using a RaspPi as the controller. (A jigging machine jerks a 1kg lure up and down near the sea bed, and pulls in a fish when it's hooked.) ...
1
vote
1answer
73 views

Really faint hissing sound from my new 12v AC to DC Power Supply

Just bought this Power supply today and once plugged in to AC, I hear a really faint hissing sound coming from the unit. Is this normal? Or should I have this replaced? Click here to see the video
0
votes
1answer
81 views

Wiring a lamp in [closed]

Hi guys I'm very new to electronic wiring so take it easy on me. I have a drone that I'm trying to connect a little 12v floodlight too so that it can see at night when it flys; the problem I'm having ...
0
votes
1answer
36 views

Operating multiple low power devices from 1 adapter [duplicate]

I have 3 WRT54G routers (12V), 1 voip gw (9V), 1 cable modem (9v) and a gbit ethernet switch (12v) which are all operating from their own adapters. I planning to build a low power (probably 12V UPS) ...
-1
votes
1answer
51 views

What is my capacitance? [closed]

I have a current measurement of 300mA on an MCU evaluation board. If my power supply is 19V or 12V what capacitance do I need to use in order to limit the voltage fall to 5V?
0
votes
1answer
42 views

12v LED Turn on and Dimming based on either MAP signal, or RPM of Car

I've got a simple 12v Red Led strip installed in my car, and i currently have it hooked upto a relay which turns it on when you unlock it from the key fob (the same as the interior / courtesy ...
0
votes
0answers
33 views

Charging Two 12V Batteries in Parallel with One Charger

I have two 12 Volt batteries in my van, Main and Aux. My battery separator is a uni-directional solenoid (Sure Power 1314-200), that will close when the Main receives a charging voltage of 13.5 V or ...
0
votes
1answer
81 views

Need circuit for 12 volt 2 Amp step down power supply from 18 volt 1.5 Amp Input

I have a power supply which outputs 18v 1.5 amp. For the purpose of my project, I need a 12v 2 amp power supply. I was wondering, if I can make a simple buck converter to convert 18v 1.5amp DC to 12v ...
-1
votes
1answer
41 views

Replace a 6v synch. motor with a 12v synch. motor in holiday decoration

I have a Santa fibre optic decoration that has a TYC-30 AC6V 5RPM (.8-1W) synch. motor that's very noisy so I want to replace it. I can't seem to source a 6V version of this motor from the ...
0
votes
1answer
67 views

12V active-low on/off switch

I have a microcontroller that I want to install in my car. One wire coming from the car supplies +12V from the battery independent of whether the car is on or off. This works fine to power the ...
0
votes
5answers
410 views

Using more than one voltage regulator in series

Is there any problem (in addition to a likely loss of current) in using more than one voltage regulator (L7812CV) in series? And is there a real gain in stability? I ask this because I 'm going to ...
0
votes
2answers
75 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
1answer
24 views

~12VDC+ Automatic Dimmer Switches

Most automotive vehicles typically have their interior lights fade out 30 seconds or so after the doors are closed. The way I understand it, closing the door will usually depress a momentary on/off ...
2
votes
1answer
91 views

Replacing alternator warning lamp with LED

I have an alternator on an in-board motor in a boat, I have almost completed re-wiring the electrical system and am wondering if it is possible to replace the existing filament lamp. I have ...
1
vote
3answers
279 views

Led strip dimming

I have a problem with my led strip starting to flicker/flash when I send a low pwm signal from my arduino (analogWrite 1-79). Here's a video: https://www.youtube.com/watch?v=X8wHzEQ4Wvw I'm using a ...
0
votes
1answer
85 views

Got a 12v 30a PSU but minimum output is 21v [closed]

Some months ago I got one of those cheap switch PSU from Aliexpress. Now I started to work with it and befor plugging in to my electronic device (which requires 12v) i noticed i could not get lower ...
0
votes
0answers
60 views

Trailer Brake Converter / Turn Signal Priority

I am trying to build a Trailer Brake Converter or a Turn Signal Priority circuit. Basically, the wires I have coming from the car are a Tail Light, Brake Light and then a Turn Signal Wire for each ...
0
votes
1answer
149 views

12v DC Voltage Drop under load

I have a Autopilot PCB which runs a 12v dc hydraulic pump which has been running fine until now. When the pump is not attached the output from the PCB is 12v. When i connect the pump the output drops ...
0
votes
0answers
77 views

higher Voltage Capacitor on the output wire of a 12v DC adapter

currently working and already made a 12v lead acid battery charger using the following components: 13.8vdc 1amp output transformer 4 diodes as rectifier 1 25v 450uf capacitor 1 automotive light ...
25
votes
8answers
8k 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 ...
-5
votes
1answer
59 views

12v pcb relay flactuate on 555 bisatable circuit [closed]

I am using a 12v pcb relay on a 555 bistable circuit.but the relay gives tik tik sound continously.what may the probale reason. I want to use the circuit for automatic warer level controller using pin ...
0
votes
1answer
79 views

Can i make a stepper motor stop at 120° increments?

I have another project, but being much less than a beginner with programming chips I am coming to you fine people for help. The basic premise is that I want a motor to turn within a full 360° cycle ...
0
votes
0answers
47 views

How to selectively switch on a ground 12v automobile application

I'm a bit of a beginner at electronics but learn fast and am very interested in this. I have a project and I'll try to simplify it to make it clear. I have a simple light circuit attached to a switch ...
1
vote
1answer
146 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, ...
0
votes
1answer
137 views

12v Latching on/off switch with momentary function

I'm looking to control a flashing light unit in my car that has several selectable patterns. It uses basic 12v+ to power and a basic +12v momentary to switch to the next pattern in a logical list. ...
0
votes
1answer
219 views

Can I use a 12v battery to power my 89W TV [closed]

I want to use a DC 12V battery to power my 89 watts LED TV. Is it possible and how long will it last?
0
votes
1answer
99 views

can i use 12v battery while charging? [closed]

hello guys i have 70AH 12V battery and i have triple phase charger can charge from (0 to 140 ah batteries ) the chager turn off automatically when the battery full charge and i have 12V to 220 V ...
1
vote
2answers
249 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 ...
3
votes
2answers
2k views

How can I model a relay in LTSpice IV?

I would like to use a 12V relay in my LTspice circuit, however there is no relay in the component list. How can I do? Relay model: SRD-12VDC-SL-C
1
vote
2answers
198 views

TEC 12706 not drawing more than 1.6A when powered by a 12V PC SMPS

I have recently bought TEC 12706 device from Sunrom.com; The specification says that the device can draw more than 6A current at 15.4V and internal resistance is ~2 ohms. But when I measured the ...
1
vote
2answers
136 views

How can I detect which DC power source to send to an underwater camera housing?

I have a small problem and hoping someone can help: I am trying to design and build a reasonably universal underwater housing for some different cameras. there is a breakout box on the surface and ...
1
vote
1answer
87 views

Solenoid Valve blowing power LED - how can i protect the LED?

I have this simple circuit setup and working well to turn a solenoid valve on (close it) and off (open it again) for a watering system I use. missing is an on/off switch before the VCC. However, I ...
0
votes
0answers
74 views

What tool can monitor voltage on a bundle of wires?

I'm working on a vehicle and trying to determine which wires control which circuits - power windows, power locks, starter, trunk release, etc. I've searched but have not been able to find the wiring ...
-6
votes
1answer
63 views

running motors from ownely coupled generator [closed]

i want to do the experiment on motor generator my design is iamgoing to connect a 2 dc motors and 2 dc generators in that 1st dc motor and 1st dc generator is coupled 1st dc motor and 2nd dc motor are ...
1
vote
5answers
1k views

how to provide light for multiple 12 v led lights for 2 weeks

I'm participating in an art show soon in which I am making "sculptural light paintings" of which require a few 12v LED strips. They're the kind that work in aquariums and car's taillights and whatnot, ...
-5
votes
1answer
308 views

Using a power bank to power a router for a few seconds [closed]

Where I live, the electricity often goes out for about 15 seconds, until the backup generator kicks in. I need a cheap way to protect my wireless router and keep the connection uninterrupted for ...
0
votes
2answers
41 views

Use a li-ion battery at two different voltages

I scavenged a li-ion battery from a broken laptop. It is made of 6 Samsung ICR18650 cells (3.75V 2800mAh), parallels two by two so that the total pack is in fact the sum of 3 cells at 3.75V, so 11.25V ...
2
votes
2answers
217 views

Basic 12V Step-Start Circuit For Automotive Fans: Troubleshooting

To keep this short and sweet, I wanted to make a circuit/controller to decrease the inrush current on a large powerful fan for my race car. I ideally just wanted something that wouldn't let the amps ...
1
vote
1answer
76 views

Using 12v to supply a Raspberry Pi with a switching regulator

firstly please forgive any confused terminology, I'm not an electrical engineer by trade! I have a Raspberry Pi which is operating a series of relays via its GPIO pins. On the other side of the ...