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Allowing for the flow of power or information without shared electrical nodes

0
votes
1answer
74 views

Controlling a high voltage relay by a PC USB

My 2.1 speaker's transformer is consuming active power even when the PC is off. I know it because it is always warm. Thus, I want that only when my PC is operating the transformer will get the AC ...
5
votes
2answers
374 views

RS 485 ground signal and chassis

I have a shielded twisted pair running from one device polling several devices in an RS 485 loop. The conditions: The devices are in parallel as they should be. The termination resistors are in ...
0
votes
2answers
56 views

Automotive signal isolation - alternatives to optocouplers

I'm working on an automotive project, where I'd like to interface various digital signals to an MCU. The signals can either be ON/OFF (e.g. radiator fans) or measurements of pulse frequency, width, ...
2
votes
4answers
61 views

Proper insulation of wires connecting to the submersible pump (5V)

I'm building a simple plant watering station, which uses a relay-controlled submersible water pump (this one). The intent is to submerge the pump into a large enough water container to avoid frequent ...
0
votes
2answers
73 views

How can I split a 5v power supply into 4 isolated (no shared ground or live) channels?

I need to power a number of tp4056's with the battery outputs in series (using tp4056's because I have a bunch already, and because I want to be able to add more cells in series later). If I do this ...
2
votes
3answers
667 views

How does Galvanic isolation work?

I am unable to understand how does galvanic isolation work either via an optocoupler or a transformer. In an optocoupler, the input side current caused LED to emit infra red light which basically ...
4
votes
1answer
119 views

Insulation Voltage of Aluminum PCB - With and Without Electronic Components

We are working on a product that contains an LED module consists of 66 LEDs (33s x 2p - 100VDC load voltage). We'll use aluminum PCB due to the thermal requirements but the customer requirement ...
0
votes
2answers
64 views

What to look for in an isolation transformer?

What do you want from an (isolation) transformer besides it having the minimum voltage/current/power(/frequency?) specs that the to be isolated device needs? Does it matter whether the transformer is ...
0
votes
1answer
42 views

Isolating Power in Communicating 5V Sub-systems

I have been plagued by a sensor sub-system which, when connected to my base micro-controller platform, intermittently causes issues that I would categorically associate with power sequencing issues at ...
0
votes
2answers
52 views

Current loop protection from wrong connection of the wires

I have built a current loop protection circuit based on the topic Using a microcontroller ADC to measure a 4-20mA sensor It works good. The next step is I want to protect the input of the circuit ...
0
votes
0answers
28 views

Increasing isolation in power splitter

I want to use This module\minicircuit Power splitter. I am working on the 2.4GHz to 6GHz band. The isolation parameter on the stated for these frequencies in the "Typical Performance Data" table is in ...
0
votes
0answers
38 views

A heat resistant connection between power supply and a resistive wire circuit (heat grid)

I'm wondering about methods to isolate thermically from the power source a resistive wire circuit (main function: to heat things). I'm sure there is a non-DIY solution (i.e. "buying something") which ...
0
votes
1answer
42 views

Convert dB to resistance

I am new to this, but I wanted to ask how it would be possible to convert a dB value into resistance. I've been looking at an isolated analog switch from http://www.ti.com/lit/ds/symlink/ts5a3359.pdf ...
1
vote
3answers
173 views

Shock from Capacitive Coupling

In an AC supply which is not earth grounded, I see a small amount of current flowing to ground from both wires of the supply (live wire has higher) even though the circuit is incomplete. It is due ...
0
votes
0answers
30 views

Isolation of circuitry from heat source

I'm building an electrolysis unit which will comprise a refractory crucible, containing the electrolyte and the electrodes. The heat will be generated from a furnace to aid the desired reaction. A ...
1
vote
0answers
57 views

Need a system to isolate an external charge circuit in a vehicle

I am looking for some assistance with options in isolating 2 parts of a circuit. I have a 4G hotspot that I am using in the car, powered via the cigarette lighter socket (rated at 12V/10A) and a 5V ...
0
votes
1answer
58 views

Designing flyback converter - multiple isolated outputs

Can I treat 2 secondary coils with dual voltage output as one with double voltage for the purpose of calculations? This seems to be OK for all formulas based on output power as technically the ...
0
votes
0answers
57 views

Designing isolated flyback with multiple outputs

UPDATE: as suggested, I split this question into separate parts (links below). I left the last one here. It is so silly I am rather proud of it ;) UPDATE 2: it seems that breaking one post into ...
0
votes
2answers
84 views

Were do ground pins on isolation transformer go [closed]

The outputs from transformer have a ground. Is output ground earth ground? Isn't the whole point for those transformers not to provide earth ground potential? Example:
0
votes
4answers
43 views

Isolation with inverter

Say I used a 12v car inverter powered by a 12v brick connected to ac mains (no ground pin) to isolate a scope and bench dmm, the inverter has no earth ground. Is the equipment isolated? Is lack of ...
2
votes
2answers
128 views

Cheap isolated mains current measurement

I'm looking for cheaper ways to measure current in a load switched by optoisolated TRIACs, without losing galvanic isolation (no breakdown below a couple kV) between the microcontroller and the load. ...
0
votes
1answer
28 views

Isolation between measuring voltage from low current circuit?

simulate this circuit – Schematic created using CircuitLab I have a low current current circuit and I would like to be able to measure the voltage on one point of the circuit but have ...
0
votes
0answers
40 views

how necessary is an isolated DC/DC for an ESP32-wroom-32 digital circuit in an automotive 12/24v System?

I want to use an ESP32-wroom-32 into an 12/24[v] vehicle. To eliminate ground loops and separate the digital circuit. In my first circuit, I use an Arduino, an LM2596 step-down module, and ltv-826s ...
0
votes
2answers
120 views

floating ground

For a big machine (rope shovel) we put a custom electronics board (gps) in an enclosure. It is connected to the cabinet with Power over ethernet (POE). The POE switch is connected to an isolated power ...
-2
votes
2answers
57 views

what is the meaning of isolation of transformer between i/p to o/p is 1 kv & mains supply to body/chassis is 2 kv

I have to design a transformer with isolation factor as follows:- Isolation between i/p & o/p is 1Kv Isolation between mains supply to chassis is 2.5Kv How to calculate these isolation factors ...
1
vote
1answer
32 views

Isolation of voltmeter via DC->AC->DC conversion

I bought a combination ammeter/voltmeter which has the restriction that the measurement/display circuitry must be powered from a different source than the measured voltage. What is the underlying ...
0
votes
2answers
89 views

Safety: Mains step down transformer vs SMPS for bench power supply?

Between a mains step down transformer and a SMPS, which would be safer for a bench power supply? I cannot look inside the transformer in either case to judge the insulation quality. But, if the ...
0
votes
1answer
42 views

Dual battery setup

I want to make a dual battery setup on my car. Doing some research I came across the two main techniques to do this, both based on isolate the two batteries being fed from same alternator to avoid ...
0
votes
1answer
36 views

Do I need different isolations among long-wire switches?

I'm playing with an MCU board (like Arudino) to read the state of several switches in my home (i.e. magnetic switches). The wires between the sensor and the board are quite long: 15+ meters in a star ...
1
vote
1answer
68 views

galvanic isolation for lm555

Hi guys I am trying to implement galvanic isolation for my lm555 square wave generator. I am designing a marx generator so this is essential. I am new with transformers, at the moment all I want to ...
0
votes
3answers
291 views

Is galvanic isolation needed when the output voltage is higher than mains?

For a flyback converter, 120 V AC in and 400 V - 2000 V out, is it necessary to provide galvanic isolation between the input and output? First, from a safety point, would not having a direct ...
2
votes
1answer
80 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
1answer
349 views

Ground loop isolation of a USB-powered device

I have a device (Device 1) that is bus-powered via Full-Speed USB and that is drawing up to 400 mA from a laptop. Device 1 has a DAC that can output an analog voltage to another device (Device 2) ...
0
votes
2answers
61 views

isolating between two power

for better isolation and because of sparking at the contacts, it is suggested using a separate supply with optoisolation like an image attached, but in my design, I wave only one power supply and I ...
3
votes
1answer
56 views

Isolation for TO-247 Leads at High Voltage (1000V)

Regarding the fairly new High Voltage SiCFET Devices with operating voltages of 1200V+ in leaded TO-247 packages (or variants thereof): How to isolate the Gate-, Drain- and Source- leads (and ...
1
vote
2answers
152 views

What is the exact name of this type of transformer?

I know, it is a (1:1) isolation transformer [wrong, see answer], found in some power supplies. However, when I search on this I get all kind of transformers except these. I have searched with the ...
0
votes
5answers
118 views

Isolated mains sensor

I’m building a mains sensor that should be able to operate safely at a voltage of up to 650VAC. I’ve already built one before, that operated with 130VAC, which I successfully monitored with a MCU, and ...
0
votes
0answers
91 views

what is the function this capacitor on the circuit? [duplicate]

I would like to ask a brief question about the function of the capacitor ( C57 ) used in the circuit below the image taken from an applicaation note which is about Voltage Sensing http://www.ti.com/...
2
votes
1answer
68 views

Proper way to route high-voltage tracks near THT components

I think this is not a duplicate of this question. My design has the following constraints: type and position of connectors pinout assignments 260 VDC / 2A for high-voltage tracks 12V / 200 mA for low-...
0
votes
3answers
127 views

what happen if a high voltage connects to pc-based oscilloscope's ground?

What happens if a high voltage (for example 500V) is connected to PC-based oscilloscope's ground? In principle, nothing should happen, but if somehow the PC's ground and high voltage's reference tied ...
0
votes
1answer
115 views

Designer circuit using optocoupler

I have a raspberry pi trying to drive an intercom system. The intercom has a 12V output which when connected to ground opens the door. What I want to do is have the raspberry pi 3V GPIO switch ...
0
votes
2answers
65 views

Can an isolation amplifier be used to block common mode noises and capacitive coupling?

A single-ended earth grounded data acquisition board have some channels fixed inputs as transducers. But when I connected extra channels as any of force transducer amplifiers, this causes standard ...
0
votes
1answer
134 views

Charging Li-Ion 4S with TP4056 (DC isolation)

I want to power a "suitcase boombox" amp using 4 Li-Ion 18650's. To charge these batteries I'm thinking TP4056, because they're small cheap and have nice charging features. From what I have read so ...
-3
votes
1answer
75 views

Earth ground issue

We are using high power laser pulse generating equipment for an experiment. Then we are using spark plug to generate flame. The spark plug is connected with isolation HV transformer 10kV shown in fig. ...
-1
votes
1answer
220 views

Why is it called “galvanic” isolation? [closed]

What makes a device Galvanically isolated? This term is commonly used and yet I haven't been able to find a explanation clear enough that I can understand. Take for example SMPS. In such device a ...
2
votes
1answer
57 views

Best way to isolate RF Coupling (2,4 GHz - 2,5 GHz)

I bought an ADF4350 PLL board from china. On the board there are 10 pins (programming and supply) which are connected to my BLE board (with an integrated antenna). Im observing following problem: ...
0
votes
0answers
63 views

Can I use the same power supply for two isolated CAN buses on the isolated side?

See the following picture. I'm making a control board which needs to communicate with two extra boards by CAN bus. I use up all isolated power supplies on my control board and don't want to add a new ...
0
votes
2answers
223 views

What are ways of isolating/splitting one DC power source

I'm building a 6S Lithium Ion battery pack with a nominal voltage of 22.2v. The pack will be enclosed so taking the batteries out to charge them is not practical; therefore, I'll need to add the ...
2
votes
1answer
82 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
1answer
87 views

Designing dimmer circuit for main

I saw a dimmer on instructables and try to create circuit and pcb for it. However the it looks nice and probably will work but I'm not confident the reliability on long run. So my question would be if ...