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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0answers
40 views

Solar Powered Lantern - Year 9 Project Idea

I am a Year 9 engineering teacher and I want to revise one of my current projects to be better but I need some help. The project idea is using a 1.5v Solar Panel (from a solar garden light) to charge ...
0
votes
1answer
36 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 ...
0
votes
0answers
17 views

Reconnecting a tip to the power supply of a Asus eeeBox PC model B202 (12v 3amps) [closed]

The power supply socket on the Asus eeeBox PC model B202 clamps down the tip of the power supply. The power supply tip is 4.8mm by 1.7mm. The reason the power supply tip is clamped down is because ...
0
votes
2answers
34 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
1answer
50 views

Regulator to feed Arduino VIN with 12V?

I am quite new to electronic and I'd like to build a setup plugged with a 12V PS (because there is a water pump in my setup). But at the same time, I'd like to feed the Arduino VIN with the same ...
0
votes
1answer
62 views

Relay driver from microcontroller

I have put together the following circuit to drive some 12V pumps from a micro-controller using a ULN2003, but it has a few issues. First issue is that the relays click in immediately. I want the ...
1
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2answers
82 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: ...
1
vote
1answer
89 views

Xbox one power adapter wiring - converting it to a 12 volt power supply

Thanks for having a look at my question. I know this may seem like an odd question but here is the history of it. I have a Solidoodle 4 3D printer, Its powered by a knock off xbox 360 brick adapter ...
0
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3answers
55 views

12V motor controller + 20V sensor

What I am projecting is to substitute the manual throttle for a little electric motor with an Arduino computerized one based on two sensors that yields 0-20V. But Arduino works with 5V, so I need a ...
-2
votes
1answer
34 views

Which better charge method for 12v 10w solar panel to 2x 6v 4.5ah battery?

i have 12v 10w solar panel and 2 x 6v/4.5ah battery. Im planning to build control that charge 12v battery (in this i series 2x6v battery) and after i read this Do batteries in series equalize charge ...
0
votes
2answers
60 views

Changing battery from 12v SLA to 12v Lithium, how can i accomplish this setup?

I am thinking of more speed for a kick scooter project. I have a 800w hub motor for this scooter but at only 40Km/h i am thinking of making it go faster. Now I know that increasing the voltage from 48 ...
0
votes
1answer
30 views

Run CB Radio from AUX power [closed]

Sorry if this isn't the right place for this. I have a Uniden UH015SX (https://www.uniden.com.au/resources_main/pdfs/uh015sx_OM_2yrWarranty-Updated.pdf) which requires 13.8v of DC power, but I'd ...
0
votes
0answers
51 views

High side switch always closed, because driver BJT is always closed

I'm a hobbyist when it comes to electronics. I'm trying to run a 12vdc fan with a high side switch switched from a 3.3v microcontroller. I've got it on a breadboard and the switch is always closed ...
0
votes
1answer
42 views

Wiring a car radio with two power sources

This is on a land rover I'm helping sort out for an off-road expedition I'm trying to wire up the radio with two different power sources, but what I've got at the moment is having some undesired ...
0
votes
1answer
55 views

Optocoupler delay off MOSFET solenoid

This is to trigger a 12v solenoid (acting as a laser shutter) with 5v (JP2) thru an optocoupler. The problem is 5v line have bit fast interruptions on a laser show, so I'd like to add a bit of delay ...
-5
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1answer
141 views

5 Led 12v battery level indicator

I've seen some simple 10 led level indicators such as this Due to space I cannot use 10 leds, how can I reuse this circuit or another for a 5 led indicator?
0
votes
0answers
39 views

12v water heater cable

I am looking for heater solution which would run on 12v dc. Heater would be used to heat small water volume (3-10l) to temperature 25-28 C. Heater must be aquarium safe. I found ...
0
votes
1answer
69 views

How long can I run a 1200w car amp on a 12v 50ah battery?

I'm looking to build a portable amplified speaker and want to know how long a 1200W car audio amplifier will run on a 12v 50ah battery supply?
0
votes
1answer
46 views

using 8 AA or Ni-MH batteries instead of one 12V 23A type battery to power a remote receiver

Sorry for the novice question, but I am thinking there should be a simple solution. I work as a magician and purchased an effect where a snake puppet in a basket goes up and down on a battery powered ...
0
votes
1answer
52 views

Use 5w/3w 12vdc LED on 60w 12vac cdi ignition

I'm building a vintage two stroke race bike out of a 78' puch maxi. The original points setup is junk and I'm switching to a CDI. I have an LED headlight that I'd love to use for aesthetic purposes. ...
-1
votes
1answer
68 views

Help with son's 18 V car [closed]

I need help with the wiring on my son's car. I'm trying to run 2 x front and 2 x rear #QG550 12 V 45rmp motors using independent 18 V power supplies, 18 V front and 18 V rear. I wish to keep the ...
-4
votes
1answer
71 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
45 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 ...
4
votes
2answers
187 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
83 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
3answers
224 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
62 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 ...
0
votes
1answer
122 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
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1answer
81 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
84 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
47 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
52 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
66 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
1answer
155 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
44 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
88 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
440 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
95 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
27 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
111 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
692 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
107 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
1answer
230 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
96 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 ...
28
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8answers
12k 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
100 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 ...
1
vote
1answer
238 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
170 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
333 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
118 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 ...