Questions tagged [isolation]
Allowing for the flow of power or information without shared electrical nodes
687
questions
2
votes
1
answer
111
views
Isolated flybacks in series to generate high-voltage [closed]
I'm considering placing isolated flyback converters secondaries in series such as the image below. I want to drive the transformers individually using synced clocks (such each transformer has its own ...
- 357
0
votes
1
answer
120
views
MCU signal isolated and Amplified (Optocoupler+BJT+Mosfet)
I've com up with the following design.
I feel I've used too many components, don't know.
but I have some reasons for anything included in the design.
PULSE_A : some low frequency (50~1000Hz) low duty ...
- 37
1
vote
1
answer
49
views
Wurth transformer secondary pins on left and right side of transformer
I am looking to use Wurth Transformer 750310988 and I have noticed its pinout is very bizarre. My application is I want to float the secondary of this transformer up to 500VDC and provide a isolated ...
- 357
2
votes
3
answers
275
views
Isolation transformers and short circuits
For some quick background and info: I'm a relatively fresh (~2y/ experience) EE in the solar field. I work in the R&D department of my company. My country operates in a 230/400V 50Hz grid.
We are ...
- 29
0
votes
3
answers
83
views
Understanding RS422 and choosing drivers
I want to communicate 2 MCUs using RS422. I need to have some isolation, so the driver should have 3.3V side and 5V side, isolated. All I can find in the market are half-duplex drivers, I understand ...
4
votes
0
answers
56
views
Mixed pollution degree creepage distance
Say you need to comply with a creepage distance but you can't do it under a specific pollution degree. I had 2 scenarios where I had mixed pollution degrees:
The creepage distance is almost enough ...
- 866
1
vote
2
answers
129
views
How can we safely test a mains powered device?
We have small non-isolated 230VAC devices that transform mains to LEDs running at 32V, 20mA. The lights are directly connected to live, neutral and earth like a standard lightbulb would be. Since ...
- 11
0
votes
1
answer
86
views
In aircraft power supply, why is the neutral not connected to chassis GND unlike household utility power?
Usually the chassis of any household equipment is connected to earth ground for safety.
Part of the culprit is neutral being connected to Earth ground. (Reasons are mentioned in this post.)
My ...
- 2,769
2
votes
0
answers
39
views
Ground isolation in multichannel mixed-signal systems
There are some similar questions to mine but I have a few more specifications on top of them. Therefore, I am not 100% sure whether to ask as an iteration or present my own question on a clean slate. ...
- 121
4
votes
2
answers
113
views
Isolation Topology in SMPS
I have been researching SMPS designs as a hobby recently and finally have the courage to build one for theoretical and practical understanding. I have chosen an isolated design looking at several ...
4
votes
9
answers
2k
views
What options exist for isolating a high power DC analog signal? [closed]
I have a high power DC signal that can range from 0-325 VDC. The source is capable of delivering up to around 150 amperes at 325 volts. I need to monitor the voltage as an analog signal by reading it ...
- 49
0
votes
0
answers
50
views
What is wrong with my double pulse test Ltspice schematic? Gate pulse is not getting generated when I connect the gate driver for 800V application
What is wrong with my double pulse test LTspice schematic? Gate pulse is not getting generated when I connect the gate driver for 800V application. Any connection error?
- 47
1
vote
2
answers
91
views
What does 2xMOPP really mean
I am a student and I am designing a medical device that has a type CF applied part.
I know the specifications that the applied part must comply (4kV of insulation, 8mm of creepage, <10μA patient ...
- 11
1
vote
1
answer
54
views
Isolate current flow in Ltspice using switch
I am trying to control the flow of current by the switch SW, I have used an independent current source I. However the switch is ineffective to isolate the resistor R1, because the switch is basically ...
- 13
0
votes
1
answer
61
views
Do I need to connect a resistor at the output of an isolated DC-DC converter module?
I am using D050505S-1WR3 in my design for powering an isolated CAN transceiver. The can transceiver is the ISO1042BDWV from TI.
Below is the schematic of the power supply and CAN transceiver.
During ...
- 1,781
0
votes
0
answers
49
views
How to eliminate the VFD noise affecting digital sensor reading?
I have a problem getting correct readings from a 5v digital sensor connected to an Arduino Uno board. I get correct reading until I start the VFD that drives a 3-phase motor.
The sensor reading then ...
- 115
0
votes
2
answers
64
views
Can you draw power from the ADUM4160 USB isolator
I am developing a USB powered medical device and I am thinking of using the ADUM4160 to isolate the USB from the device.
However, there is one thing i didn't understand about the device: does it ...
- 11
0
votes
0
answers
106
views
I keep Blowing up my i2C (ISO1540) isolator when plugging and unplugging my battery
I am using a ISO1540 to read the SMBus of some BB2590 batteries. The relevant part of the circuit is shown in the images below
The issue that I am having is that sometimes when connecting or ...
- 1
0
votes
1
answer
53
views
Isolation of Input signal and supply [closed]
I have this op-amp like circuit. Where the input signal is an 70V High voltage signal and the power supply is 3.3V voltage signal to a MCU GPIO.
My question is how should I isolate the high voltage ...
- 1
0
votes
2
answers
176
views
How to make a smart precharge circuit
I want to build a circuit that monitors the voltage at either end of the precharge resistor circuit.
Since the load will have capacitance, I should expect an RC time constant curve on the load of the ...
- 2,077
0
votes
0
answers
42
views
Connecting LVDS to oscilloscope using ferrite bead to isolate GND/SHIELD
I want to measure LVDS signals with a scope.
Will my solution work? (Shown at bottom.)
I know of other ways of doing this, but I am hoping this way is cleaner and easier.
Specs:
Frequency:~100MHz
...
- 683
4
votes
0
answers
54
views
Erratic and confusing I2C behavior between ATSAMD21G18 and A89307 through ISO1644 isolator
I'm working on a BLDC driver using Allegro's A89307 controlled by an isolated ATSAMD21G18 via TI's ISO1644 I2C digital isolator. The simplified I2C connection is shown below, I omitted all the bypass ...
- 41
0
votes
1
answer
39
views
Isolate modus IC
I want to isolate the RO, DI, and RE/DE pins going to the microcontroller. Can someone suggest what sort of IC would be appropriate for this application?
I wanted to use the FOD8012AR2, however, I see ...
- 2,077
1
vote
2
answers
58
views
Isolate unpowered MCU UART
I'm an EE student working on my first hobby project involving ECAD and currently I have an ESP32-C3 connected to a BM83 Bluetooth audio module via UART.
There will be moments when only one MCU is ...
- 13
1
vote
2
answers
61
views
Multiple 4-20mA Transmitters from Common Referenced Analogue Inputs
I'm trying to come up with a scheme for multiple loop powered 4-20mA transmitters controlled from seperate analogue voltages, which all have a common 0V reference. My inital thought was to use an ...
- 163
0
votes
2
answers
83
views
Should consumer electronics have low voltage isolation?
I am making a MCU (PIC12) controlled 230V relay system. They will be operated from 230V mains. Should I use isolation (1:1 transformer?). I would use this converter for 230VAC-5VDC (or something like ...
- 957
2
votes
2
answers
133
views
Removing noise from USB audio CODEC
I've created a USB audio codec using the TI PCM2912A.
The feature I use the most is the Audio Sidetone functionality, which plays back audio
from the mic so that you can hear yourself talking.
I use ...
- 23
0
votes
0
answers
35
views
How isolate IO pins of Arduino and PSU output?
I will start by saying that I am a beginner of electronics and I don't have much experience hence I am making this post asking for advice from more experienced peopled than me.
Now that I have lowered ...
0
votes
1
answer
34
views
Power supply of isolation amplifers
First time experimenting with a design with isolation amplifiers and I am unsure about the amplifier power supply range I need.
I need to provide isolation to measure a current between 0 and 7.4mA. ...
- 75
0
votes
0
answers
57
views
Basic Wiring Help
I’m an individual that likes to tinker around with things and I’m asking for help.
I’m in the middle of a car audio system update. I currently use a basic relay as a “turn-on” switch for my ...
- 1
2
votes
1
answer
129
views
Is it okay to supply two channel of isolated gate driver with same DC/DC converter?
I am planning to use NCP51560 isolated gate driver in my project. Here is the block diagram of the gate driver.
I need isolation between primary and secondary side. I don't need an isolation between ...
1
vote
0
answers
87
views
How to get USB 3.x power but with data limited to USB 2.0 HS?
I am designing a device with a few interesting requirements. Due to power requirements, we need to draw 900mA, but due to isolation requirements, we're limited to the 480Mbps rate for our primary ...
- 11
2
votes
2
answers
96
views
Back calculating the input from output signal chain with an isolated amplifier and opamp
We are measuring the voltage of a charger using the below circuit with the help of an ADC present in a microcontroller.
The value of charger voltage is required for some other applications. The value ...
- 1,781
0
votes
0
answers
32
views
How to interface an isolated microcontroller to an integrated h-bridge?
I have an ESP32S3 microcontroller powered by an isolated DC-DC converter
and I would like to use this integrated h-bridge to control a DC motor. The power supply can be either 12 or 24V.
My gut ...
- 75
1
vote
4
answers
536
views
Isolated DC voltage measurement via optocoupler
I am trying to make a circuit that measures 10-30V DC with isolation. The measurement is done by the circuit, not manual. The measured voltage level/information is sent via an optocoupler to the ADC ...
- 11
1
vote
1
answer
49
views
Grounding a node referenced to different ground
I'm currently working on a dual supply solution (POE + DC (called Main_Alim)) for a project.
I want to disable PoE negaciation when DC is present. For this, I need to connect the node between R7 and ...
- 6,238
0
votes
0
answers
92
views
PoE supply : what isolation is garanteed?
I'm currently designing a PCB that will be powered by PoE (or external supply).
I have some doubts about what isolation the PoE supply (PSE, typically a PoE switch) is guaranteed to provide :
are the ...
- 6,238
1
vote
1
answer
247
views
SWD isolator solutions
I'm looking to implement an isolated (reinforced, >500V) isolation circuit on the PCBA side that would allow for SWD programming of MCU such as STM32 using JLINK / STLINK etc. The interface is ...
3
votes
3
answers
458
views
Optical TOSLINK for high voltage isolation up to 2kV?
When using optical TOSLINK cable for isolation, would there be a problem in using it for measurements up to 2kV? I don't envisage any problems, since the optical cable is made of non-conducting ...
- 1,053
0
votes
0
answers
59
views
Placing transformers in parallel to increase current
I am trying to create an isolated 5V 1.5A power supply. After doing some research, I decided to go with a SN6505 to driver a transformer to gain isolation. However, maximum current output of the ...
- 185
0
votes
1
answer
267
views
WS2812/15 opto-isolated with 6N137 and MOSFET?
The goal
I want to isolate a 3.3 V MCU (ESP32 C3) from a WS2815-Strip but I had no luck so far. I already read these threads, because I think they're dealing with a similar problem:
MOSFET - 800 kHz ...
- 11
0
votes
0
answers
44
views
2 ESP32's GPIOs to same header pins isolation
Hey all I am wondering if my idea below would work.
What I am wanting to do is connect 2 (really 3 ESP32's and 4 ATmega32u4's) micro controllers (in the example there are just 2 ESP32's for simplicity)...
- 731
1
vote
1
answer
961
views
Insulation resistance or isolation resistance?
is there a difference between "isolation resistance" and "insulation resistance"? What is the correct term?
I have a definition:
"Electrical resistance with an often high ohm ...
- 11
7
votes
2
answers
1k
views
Wouldn't placing capacitors between the input and output of an isolated DC-DC converter defeat the purpose?
It is common to recommend the placement of capacitors between the input and output sides of an isolated DC-DC converter, such as in this example layout:
I understand that the purpose of this is to ...
1
vote
1
answer
64
views
Review of isolated dual power supply circuit for IGBT gate driver
I need to build an isolated power supply for an IGBT gate driver. +15V, -8V.
What I'm trying:
I'm using a 1:1.3 transformer and driving it with a 15V square wave. The output voltage is split 1/3, 2/3, ...
- 143
0
votes
1
answer
97
views
Connecting two of these DC power supplies in series
I have two identical power supplies which output 16.5V DC. They seem to be isolated by a transformer and an optocoupler, but there is also a 1kV 2.2nF capacitor between the primary and secondary side (...
0
votes
2
answers
165
views
Galvanic isolation
I'm trying to understand ways of isolating circuits and general concepts of isolation.
I understand how high frequency signals can pass over a capacitor.
I understand also how optocouplers work.
I ...
0
votes
3
answers
115
views
ANDing isolated power supplies
Is there any specific challenge to ANDing two isolated power supplies, assuming that ideal diodes are used on their outputs? I'm interested in making a particularly compact PoE supply capable of ...
- 167
0
votes
2
answers
182
views
Isolation on bidirectional I/O pin
On the PCB we are currently designing we have two isolated grounds, one for the sensitive electronics (including a Jetson Orin NX SoM), and one for the outside-facing connections.
The difficult part ...
- 6,238
2
votes
1
answer
106
views
Can USB 3.0 be isolated using RF transformers?
My project requires an isolated USB connection (without power). Currently we're using a fairly expensive USB 3.0 isolator.
I was wondering if it would actually be possible to achieve smaller and lower ...
- 27.2k