Questions tagged [safety]

*Your* health and safety while working on electrical devices, and designing devices that will not shock, set fire to, or otherwise harm the user of the device.

Filter by
Sorted by
Tagged with
0
votes
0answers
43 views

Altitude (sea level) limitation for safe use of the mobile phone (Xiaomi 9T Pro) [on hold]

This article https://www.edn.com/electronics-blogs/power-supply-notes/4402833/How-does-altitude-affect-AC-DC-power-supplies- says that because air pressure decreases with rising altitude, power ...
1
vote
1answer
21 views

Current flow in trailing edge dimmer

I was trying to learn something about dimmers for light bulbs. After some reading, I found that most trailing edge dimmers contain some variant of this: Found for example in this diy-project or this ...
4
votes
2answers
548 views

How safe is using non-RoHS parts?

I was wondering the safety of using non-RoHS parts for hobby projects. I already use non-leaded solder, but some of the parts I have are not RoHS compliant. How much would I, and my family, be exposed ...
0
votes
2answers
67 views

Abusing EPS connector to power LED's?

I'm working on the wiring harness for a PC build that's going to include a bunch of (5050) LED strip lights. The strips will be wired to fan connectors (more details at end). For testing, I've been ...
0
votes
1answer
49 views

Safety Rated Sensors [closed]

I am trying to find a safety sensor for a machine. The sensor should be safety rated as it will be used to detect if a cover is removed and will shut down robotics and uvc bulbs which is harmful to ...
3
votes
2answers
122 views

Back branches in code

While reading this file on software hazards this slide says: "No Back Branch in the Code" I wonder what does it mean? Normally when we write code in C-language then we don't actually do branching ...
1
vote
1answer
111 views

Safety precautions when developing and testing mains voltage devices [closed]

Specifically, I am planning to design and build an energy meter to measure power drawn from mains - 120V 60Hz. What are the risks associated with developing and testing this device and how to minimize/...
0
votes
1answer
31 views

Protection circuitry for AC/DC converter

I'm using the RAC02-GB (Datasheet) as an AC/DC converter and I'm confused about the protection circuit they included in the datasheet: I want to make sure the AC/DC converter has the proper external ...
1
vote
1answer
60 views

Oscilloscope and Electrical Safety

I was reading an article in a magazine in which the following sentence is written about a circuit that generates a certain waveform on a load R (in which one of its terminals is connected to the earth ...
1
vote
4answers
131 views

Safety: Can I harm myself using an AC, 9V 500mA power supply for experiments?

I'm about to embark on my first electronics project and would like to check off a safety question: I want to build a bicycle hub dynamo -> USB charger based on these instructions. It is basically a ...
2
votes
2answers
99 views

Can an electrified wire ever be safe against bare skin?

This could sound ridiculous to someone with an ounce of experience, but I'm just getting started, so here we go ;) Full question is 3 parts... First, what is the lowest amperage needed to light an ...
9
votes
6answers
4k views

Why aren't starter circuits protected?

In most cars and trucks, a thick cable connects the battery directly to the starter (solenoid). Why don't these circuits have have any kind of overcurrent protection? It is an accepted practice ...
0
votes
1answer
23 views

What safety regulations do I need to follow for wiring of a decorative lamp utilizing a fluorescent tube with g10q fitting?

I'm building a cast concrete decorative lamp. It will use an exposed circular fluorescent bulb, which attaches to a g10q lampholder. I understand I will need to wire it up to a ballast and starter, ...
0
votes
2answers
97 views

Running an electric motor beyond its ratings

I ordered a 36V 500W brushed DC motor but unfortunately a 24V one came. I'm faced with the dilemma of returning it and waiting for a month before getting a refund, then ordering a new one and waiting ...
2
votes
1answer
666 views

How safety capacitor replaces optocoupler

I see some phone chargers using safety capacitor (after some research I found its safety capacitor)But not optocoupler to isolate in and out . How safety capacitors replace the optocoupler
1
vote
2answers
113 views

How does electrocution (fatal) happen? [closed]

I'm trying to make my workshop safer but I can't understand how electrocution happens. For example, one hand is touching to live wire and neutral wire is not touched. If I know right, current flows ...
1
vote
2answers
91 views

Is this the correct way to wire my transformer?

I am building a 12 V dual power supply. Since this is the first time I will be using mains (230 V). I would like to make sure that I am not going to burn down my house. The transformer I want to use ...
0
votes
5answers
176 views

How are electric water heating elements isolated?

From what I've seen and understood, electric water heating elements are usually copper tubes/pipes with electricity running through them to heat up the surrounding water. I'm not sure if the ...
0
votes
3answers
69 views

Safety and isolation transformers

What safety measures can be taken when using a 1:1 isolation transformer in order to avoid electric shock even if someone touches both ends of the secondary? Would an insulation monitoring device be ...
12
votes
2answers
986 views

How to rinse container used for ferric chloride etching?

From what I have gathered online, after etching one stores the "used" ferric chloride (more specifically FeCl2 and CuCl) in some container which can then be taken to a waste disposal facility. What ...
2
votes
1answer
80 views

Is there anything besides power factor that determines the max CFL that can be used in a socket compared to the max incandescent for that socket?

When shopping for lamps recently, I've noticed that the sticker on the socket says something along the lines of "To reduce risk of fire, use maximum 60 watt incandescent or 13 watt compact fluorescent....
64
votes
9answers
358k views

How much voltage/current is “dangerous”?

Related: Safe current/voltage limit for human contact? From what I've heard: 110 V (or 220 V; household voltage pretty much) is dangerous (i.e. can kill you) I think there's consensus on this, ...
0
votes
1answer
47 views

AC power supply safety

I am planning on building a vintage tube radio from schematics. Part of the radio will include its (multi-voltage output) power supply, with an AC power cord, AC switch, and transformers. Are they ...
0
votes
1answer
120 views

lithium coin cells, safe to completely cover? lightweight method to protect from the environment

I am trying to make equipment to measure temperature in small mammals, probably attached to a neck collar. The collar needs to be very lightweight (e.g. <3g total) so I am planning to use a ...
0
votes
1answer
37 views

Placement of varistor with respect to fuse

My design includes a pretty standard AC/DC converter powered by mains for intended use at home. For overvoltage and overcurrent protection, I am planning to use a combination of varistor and fuse ...
3
votes
2answers
709 views

Is a capacitive touch screen safe to use?

I was reading about capacitive touch screens. I understood that your hand picks some current flowing on screen. That sounds alarming. Is it safe to use a capacitive touch screen, since it picks small ...
1
vote
1answer
424 views

Proper Chassis Grounding

I'm starting to design things that run off mains voltage and I want to be sure that I have a proper connection from my chassis to earth ground. I've been reading a bit about proper grounding and have ...
2
votes
3answers
622 views

Is a separate safety earth connection necessary when using an earthed power entry module?

Testing the Schaffner FN1394-10-05-11 power entry module with a multimeter shows continuity between the ground pin and the body of the module. Consequently, when the module is fitted into an aluminum ...
1
vote
1answer
109 views

Are there more (mains) electrical safety incidents in the United States compared to the UK? [closed]

Forgive me if this question isn't exactly "on topic" for this site -- it's a bit meta. I am an academic in the UK, and I occasionally design electrical devices that plug into "the mains" in one ...
0
votes
1answer
56 views

How to measure laser class of LIDAR

I just bought a LIDAR with the intention of building an indoors robot that uses it to navigate rooms in my apartment. The manufacturer website states: Low power infrared transmitter conforms to ...
6
votes
3answers
5k views

Maximum Current Draw on Vin Pin

I don't want to damage the pins on my Arduino Uno, and I'm especially cautious of drawing too much current. I'm experimenting with a small servo motor (similar to this one), and have connected the ...
0
votes
3answers
65 views

Electrical Standards - Earth Wire at Low Voltages?

I got a question about safety standards: I'm designing a consumer device and I'm not sure whether I need an earth wire. I have an AC-DC converter plug that outputs 5 V and up-to a maximum of 1 A ...
0
votes
1answer
75 views

How to power up a project with 3 devices, between 0 and 12 volts

I'm working on a project which involves a DC heating element, a computer fan and an Arduino/ESP8266. I'd like to use one power supply for those devices..... The requirements: The heater needs a ...
0
votes
1answer
40 views

Normally Closed Negative Output, Positive Input Relay

I'm attempting to wire up my remote start in my manual transmission vehicle to ONLY start when the vehicle is in neutral. The way that the transmission works is like this: When in neutral, resistance ...
1
vote
1answer
113 views

Designing a 2S Li-ion charger with 5V 2A input

I'm interested in designing a few similar charging circuits based on the specs of the title which is getting a charging for 2 cells in series(or more) from a 5V input. Now my question is: Assuming I ...
0
votes
1answer
351 views

Using a residual current device when there is an isolation transformer

In a system, currently there is no circuit breaker and RCD, but there is an isolation transformer as in the diagram below: simulate this circuit – Schematic created using CircuitLab As you see ...
1
vote
0answers
85 views

How to know what is the safety standard to apply to a PCB design?

I want to design a PCB with some points at some KV during certain times, less than 10KV and no more than 30mA of current. After dealing with concepts and getting the main idea about my circuit needs, ...
2
votes
1answer
219 views

Designing single fault safety into class I device

I'm trying to wrap my head around safety standards for electrical equipment. My device is medical, so for me section 8 of IEC60601-1 is what really matters to me, but it's kind of my understanding ...
0
votes
3answers
63 views

What connectors should I use with 5V DC current?

In a personal project, I need to power several 5V appliances which, together, use up to 12A. I want to use a 60 inch cable between a case to which those appliances are connected, and the transformer ...
0
votes
2answers
212 views

Is it safe to measure 220Vrms@50Hz on DSO directly?

I borrowed my friend's DSO to complete my project(Hantek DSO5072), but on scope it says CAT II/400V. So is it safe to measure 220Vrms@50Hz with it?
2
votes
2answers
58 views

Earth continuity of slot together aluminium enclosure

If I were to use a slot together aluminum enclosure for a mains powered device, and I earthed one panel of the enclosure by fitting a stud, how could I ensure continuity of the earth to the whole ...
5
votes
3answers
1k views

Safety of Aluminium for enclosure earthing

To earth an Aluminium enclosure, is it safe to use a welded Aluminium stud and then use a nut and washer to attach a hook-ended earthing wire to the stud? Aluminium oxidises to develop a thin ...
0
votes
0answers
38 views

Does the Machinery Directive (EN60204) require separate mechanical Start and Stop switches?

I have a prototype machine with mechanical moving parts (all contained inside a transparent interlocked enclosure) to review. Single-phase AC power enters at the rear via a fused IEC 60320 C14 inlet, ...
1
vote
2answers
137 views

Is this a safe way to add extra current control for a DIY tDCs device?

I have put together the well known DIY tDCs-device Inthinkerator MK1, and wanted to add an extra safety feature, but I dont know if this is the correct way to do it. The original design is without the ...
13
votes
8answers
59k views

Why is it dangerous use a coiled extension cord

What aspect using a coiled extension cord makes it more dangerous than using an unrolled power cord. Many fire safety websites reference that an extension cord should not be used while coiled. Is ...
0
votes
0answers
41 views

Calculate electric field from wire with AC current through

Here an experiment picture The wire(with some resistance) connected to 220 V 60 Hz AC voltage source. The peak current through wire is 0,3 A How to calculate mean, or at least peak electric field ...
2
votes
3answers
310 views

Computer Power Supply Testing Safety

I have a 750 watt ATX power supply that I will be testing with a multimeter to make sure the right voltages are present. How can I make sure that I do this safely? Is there anything that's threatening ...
0
votes
1answer
144 views

Power supplies with medical safety approval

Regarding the data sheet of this SMPS power supply. In the first page it says: 2 x MOPP Medical safety according to AAMI/ANSI ES 60601-1:2005(R) and IEC/EN 60601-1 3rd edition Then I googled to ...
0
votes
1answer
126 views

Battery Disconnect Switch

I'm an Electrical Engineering student still new to power systems. I'm working on a project that uses a 24V and 200Ah battery bank made up of 4 AGM lead acid batteries. The batteries are supplying four ...
1
vote
3answers
102 views

Testing and safety requirements for selling homemade electricals

I am currently researching and designing electrical audio equipment, example devices: Tube and solid state guitar amplifiers Guitar effects pedals Mixing / filtering units Synthesizers Some of these ...