The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [low-voltage]

Low voltage refers to voltages in a range from 1) 50–1000 Volts AC [Vᵣₘₛ, rms…root mean square] and 2) 120–1500 Volts DC according to standard IEC 60038 of the International Electrotechnical Commission.

Filter by
Sorted by
Tagged with
0
votes
1answer
29 views

Effect of electrical arcing on the system voltage

What will be the effect of Electrical arcing (between phases or between phase and neutral) in a 415V three phase system in the downstream voltage... Will it just act as a load ( let's say the arcing ...
1
vote
2answers
93 views

How to Size Line Reactors and Understanding Reactor Specifications

I've got a 600 VAC, 75 HP VFD that I want to place line and load reactors in series with. Usually, I find charts like this that give me a horsepower table to follow as they are the easiest to use. ...
1
vote
0answers
95 views

Can I use diodes to protect power supply outputs?

(Note, this is my first question on this site, please point out if there is something that I am doing wrong here.) I have a thyratron that requires two separate power lines to attach to it. The two ...
0
votes
1answer
63 views

What is the correct instrumentation to measure a pulse height of 10's of microvolts with a pulse width of 10's of picosenconds?

I'm working with a sensing material and want to better understand its response. I have the theoritical elements worked out, but now want to begin testing and have no idea what type of tools/...
0
votes
1answer
34 views

How to make a power supply cable for a 10.5V 4.3A laptop OR how much higher voltage can I use

Let me preface this by saying I've spent countless hours researching and learning what I can about electronics before asking this, and I cannot find a clear answer to this. So sorry if this seems like ...
1
vote
0answers
37 views

Can I amplify a thermocouple Signal with the GS8332-SR OP-Amp?

Theremocouples have a very small voltage of around 0.4mV/10C. K Type Thermocouple Voltage Table I want to amplify that signal so I can read it with an ADC on my Arduino Microcontroller. The Voltage ...
1
vote
0answers
35 views

Modeling the thermal part of the Time-current curve

G’ day, I am working on designing protection devices for my research work and I am struggling to model the thermal part for the low voltage circuit breakers based on IEC standards. Based on the ...
2
votes
2answers
94 views

Why is 100 volts or less generally “low voltage” and “safe”? [closed]

In the United States in many state jurisdictions, wiring that operates either exactly at or below 100 volts is not required to be installed by a licensed electrician, and no site plan, building permit,...
0
votes
2answers
98 views

How to measure uV voltages buried in noise?

I'm working on a project in which I am analogly processing ultra low signals. The phase, harmonics and signal shape are critical to circuit functions. The signal on the input comes from an antenna ...
10
votes
2answers
837 views

Can a novice safely splice in wire to lengthen 5V charging cable?

I have a 5V 1500 mA charging/power cord for a camera that was too short to reach the mounting position I need, so at the suggestion of my electrical engineer father, I decided to try to lengthen it. ...
1
vote
1answer
56 views

Can I use network cable for low voltage DC power?

I'm a guitar player with a crazy idea for a 2 part bypass looper: Enclosure A is just big enough to house 4 footswitches and an ethernet jack. Enclosure B has 9V DPDT relays to route audio ins and ...
0
votes
4answers
119 views

What can happen if 24vdc is applied to an Ethernet port?

We have a device with two RJ45 ports. One of these ports is for receiving 24vdc on pins 7(-) and 8(+) to power the device. The other RJ45 port is an Ethernet connection. The ports are of course ...
0
votes
1answer
70 views

Device for preventing 12V battery from dying

I am looking for a device which cuts off the connection between batteries and the system just like a circuit breaker when my 12V battery goes below 9V(for example) for preventing it from dying ...
1
vote
0answers
32 views

Responsible Battery Reserve Capacity and Low voltage?

It's been asked here, but looking for clarity. How bad is it to undervoltage a 12-volt lead-acid battery? SLI automotive starter batteries list RC (reserve capacity), but I think this a usable ...
0
votes
1answer
121 views

Digital voltage stabilizer relay diagram

I am using this voltage stabilizer relay diagram below, which provides a 16 step-up level. I need to edit it, so that I can made it to work as step-down in case of high voltages such as 245 and above. ...
0
votes
1answer
106 views

Stabilize circuit on 5V 2A

I have not yet build following circuit: Circuit in high performance needs 5V 1.7A (measured). I have source which is powerbank with 16 000 mAh. Outputting via ports: USB-C 5V/3A, USB-A 5V/3A, Micro-...
0
votes
3answers
113 views

Does the Rds(on) of a MOSFET vary based on source-drain voltage?

The Rds(on) of a MOSFET decreases when you apply higher gate voltage, but does it typically vary based on the source-drain voltage? I will be using a MOSFET to switch very low voltages (10's to 1000'...
1
vote
0answers
93 views

Electric heating for glass melting furnace

Some furnaces use electricity for glass melting. Low voltage and high amperage power is passed through the molten glass through 2 molybednum electrodes dipped into the glass. The molten glass acts as ...
5
votes
1answer
56 views

How to determine which harmonized standards are relevant to achieve CE conformity declaration

We are aiming to develop our first product to achieve a CE marking. So far i understand that there are a few directives like Low Voltage Directive (LVD), ROHS, EMC, etc, which can be implemented by ...
0
votes
4answers
276 views

Too High Voltage Drop across Transformer's Output

I want to get very high current flow thought secondary winding of transformer on my 3 Ohm load. As I apply high voltage of secondary to the load the voltage across it drops dramatically. Only about 2% ...
0
votes
1answer
86 views

Reducing the start-up voltage of a low voltage cut-off circuit

I just built this circuit, with the intent to use it as a low-voltage cut-off switch for a single li-ion cell. It works great, but once it's triggered it needs about 7 volts to turn back on, so I ...
0
votes
2answers
31 views

Pros and cons of centralised vs decentralised power deliver for small devices

How does compare using one power supply for multiple devices vs each device having its own - regarding efficiency eg. power consumption? Model situation: Home automation using low power devices such ...
1
vote
1answer
164 views

How to convert high voltage DC at low amps to low voltage DC or AC at high amps?

How to convert high voltage 500 volts DC at very low amps to lower voltage 12 volt DC or AC at high amps? Must I use an electrostatic motor or can I use an op amp? The reason I am posing this is a ...
0
votes
2answers
103 views

Cheap Low Power Signal Transmission To Smartphone

For my university project I'm making a certain sensor which has to (one-way) communicate with a smartphone. The sensor needs to be as cheap/simple as possible (aiming at +- €0,50 in total) and only ...
2
votes
2answers
390 views

3.3V overvoltage limiter circuit topology

I need to design, using discrete components only, a shunt voltage limiter that drains little or no current (less than 2mA, the lower is better) at 3.3V, and ensure that, when driven at more than 4V, ...
0
votes
4answers
109 views

Can I provide a constant charge to a battery?

I have a sketch here of what seems like a solid plan. sketch I need to provide a .2ohm coil around 3.7v which will take around 20 amps. The load will be very brief; 3-5 seconds, and intermittent; ...
0
votes
0answers
413 views

Low voltage cutoff circuit with PV panel

I'm trying to build a simple reliable low voltage cutoff circuit and sufficient voltage turn on circuit for a PV panel powered circuit. The idea was to supply power from PV panel to a working circuit ...
0
votes
1answer
66 views

Safety for 48v leds in water

I'm builing a 48v DC LED system to be used inside a fountain in a public space. I'm using a 48DC 30A switching power supply. What should I do to make it safe in case any conductor gets exposed to the ...
0
votes
2answers
518 views

Determining safe current and fuse rating for LV LED lighting

My home builder pre-pulled a length of 18-8 solid copper wire (18 AWG, 8 insulated conductors inside single jacket) into the ceiling of a room where I want to use some LED lighting with a remote power ...
0
votes
0answers
3k views

Smallest circuit for Ultrasonic Mist Maker or humidifier

I am working on Ultrasonic Mist Maker or humidifier circuit, but does not found any good circuit. As search on google that we have to make about frequency 1.6MHz to convert water into mist. using ...
2
votes
1answer
91 views

Safety Standards for Low Voltage Systems

I am looking for safety standards which could be applied to the piece of equipment desribed below. Basically the piece of equipment is a housing which inherits a 24V 100Wh Battery (2x SBS60) and a ...
0
votes
2answers
77 views

Logic level for system lower than IC's recommended logic level

My system has a logic-level and logic-supply-voltage of 2.4V. I want to use a particular IC in it (which basically operates as a shift register), and the datasheet says the minimum recommended logic ...
5
votes
1answer
299 views

Multiplexer for low-voltage measurements

How does voltage leakage (or cross-talk) from a mux affect low-voltage (voltages on the range of 10s of microVs to mVs) measurements? I am building a measurement set-up consisting of a Keithley 2400 ...
-2
votes
3answers
161 views

Detect voltage below 0.7V? [closed]

I have a LED in circuit which I want a circuit to detect whether it's on or not. I have found ground and +ve of the circuit. And I checked the voltage across +ve of LED and Ground, when it is ON, it ...
0
votes
1answer
99 views

What DC motor controller will work for a small toy train? [closed]

I'm thinking about modifying a battery-powered toy train to use a higher voltage battery so the toy can go faster. Like this: https://youtu.be/qK-IVIllOBY?t=30 The 9V battery has a nice form factor ...
0
votes
1answer
954 views

PIR (HC SR-501) not working

I'm working with ESP8266 Wemos D1 Mini and HC SR-501 (PIR sensor) in one particular project (please, see the circuit image in annex). The question is the HC SR-501 stay always LOW. I tried change the ...
0
votes
0answers
100 views

Specifying & operating a TRIAC with a low voltage load

I am looking to do a circuit to switch a 12 VAC of a device to the ground. I intend to use a microcontroller to drive the TRIAC. The goal here is only to short the 12 VAC of a device to its ground. ...
0
votes
2answers
121 views

PCB relays for switching 700-1000V analog signal [closed]

I'd like to switch the polarity of a differential high voltage line that carries up to a 750V (+/-375V per conductor) analog signal. The easiest way to do this appears to be to use a dual-pole dual-...
0
votes
2answers
598 views

Low voltage disconnect with no quiescent current

I'm a noob. Please correct my mistakes. I'm making a circuit where I'd like to protect my Li-ion battery (3.7V, 3500mAh) from discharging too much. The batteries have a protection inbuilt which shuts ...
0
votes
2answers
173 views

Calculating resistance when ohm law has no response

I have a 3v DC source and a 3v light emitted diode, i want power this led with just 5 mA . There is a formula : R = V/I But in my case V is 0 V[source] - V[LED] = 0 So R is 0 always!!! How can i ...
0
votes
3answers
6k views

Circuit with 10 LEDs with 9V battery

I know that a 9V battery can only power so many LEDs. I need a 9V battery to power 10 of them maybe less or a few more and keep brightness and im not sure where to go to make it happen. Or if i ...
0
votes
1answer
84 views

How to convert 0.08 V of AC to DC

I am using an insulated wire as an antenna, which is picking up 0.08 V of AC. I want to convert that to DC. I know I need to use a rectifier, however my configuration doesn't seem to be working. I ...
2
votes
1answer
165 views

Switch off this single cell lithium hi-power LED driver with protection circuit

I've been goofing around the internet trying to build my own flash light with a single 18650, with low voltage protection circuit. For now this circuit can already achieve following ideas: Standby ...
0
votes
3answers
287 views

Isolated way to detect 240V contact closing

I want to create a small project with an ESP8266 that makes a server call when a thermostat is open or closed. My main problem is detecting the thermostat status. The electro-mechanical thermostat ...
1
vote
0answers
57 views

Unknown 2-pin weatherproof connector

We have a meteorological station (Made by the now-defunct Solar Millennium) next to our solar plant that has a faulty connector from its PV panel. It has a circular cross section and has a screw-in ...
0
votes
1answer
207 views

Using flyback diode with relay, load regulation faults occur

I'm having a problem with load regulation errors on my board. When I engage our load with a relay, it causes a metering chip in our system to reset. I've placed a picture of the relay with the flyback ...
0
votes
4answers
865 views

Low voltage cutoff circuit not working

I've spent the past 10 hours trying to figure out why my low voltage cutoff circuit won't work, and I'm at the point where I feel like I need to ask for help. The idea is to slap this circuit in ...
1
vote
2answers
3k views

Can I run a 12v fan off of a 9v power supply for LED lights and are there any side effects

I have multiple (9v 1500mA to 9v 3500mA) LED light fixtures that I have tested chaining a single fan (12v 5.2w and 12v 0.16A fans) and they seem to work under the brief test with enough air flow for ...
0
votes
4answers
2k views

AC vs. DC in Low Speed, High Torque application

My club is building a 1/4 scale utility tractor (around 800 lbs) and for the past couple of years we have been using an electric hybrid drivetrain. Our system has been a 32 hp gas motor powering a DC ...
0
votes
2answers
217 views

Biased single-source relaxation oscillator not starting

Vcc is 5 V , first op-amp LM358 provides 2.5 V ground for easiest possible relaxation oscillator build with MCP661 (2.5/5.5 V supply, 60 MHz operational range). I wanted to use it to measure values of ...