Skip to main content

Questions tagged [3.3v]

Deprecated tag. Do not use in the future.

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

Controlling On/off of WL-134 Module with ESP32

I want to control on/off of WL-134 RFID module from GPIO of ESP32. WL-134 requires 9V, 140mA on its input so Basically I want to control 9V input from GPIO of ESP32 when I dont want to use RFID module....
Zunuran Nasrullah's user avatar
1 vote
1 answer
120 views

Low power, isolated, compact 230AC to 3.3DC power supply with very low heat dissipation? [closed]

Need an isolated, compact 230V AC to 3.3V DC power supply with very low heat dissipation. No heating is extremely important as – unfortunately – this regulator will be placed enough close to a ...
Zoltán Bíró's user avatar
8 votes
5 answers
3k views

Is creating a voltage rail loop good or bad practice?

I am still new to PCB design but I often run into this. Say I have a USB connector on the bottom of a board, a SoC on the top, an LDO somewhere in the middle, and miscellaneous stuff on the sides. It'...
Kez's user avatar
  • 185
0 votes
5 answers
746 views

Is there an extremely simple circuit using 3V to have LED only on for 30 seconds?

Apologies in advance for this probably-grade-school-level question, but, of all the silly things, I want to make a light-up card that turns off after about 30 to 45 seconds. Fading would be a bonus ...
BirdsInMyBrain's user avatar
1 vote
1 answer
66 views

Detecting Bus Presence

I have a PCB that connects to an existing device through a simple parallel bus. I want a way to determine whether this device is connected or not. The data lines aren't of any help, as they are ...
Enrique Cortez's user avatar
0 votes
0 answers
137 views

Can I use a Schottky Diode to prevent a voltage regulator from being used in reverse?

When I use a USB Serial Programmer, the 3.3V line from the programmer gets connected to the 3.3V line from the circuit below. The problem is that I also get 3.3v on the voltage regulator's VIn, ...
rasco22862's user avatar
0 votes
0 answers
188 views

Drive an HX-53 IR Transmitter using an ESP32 and logic level converter

I have an ESP32 with which I need to drive an HX-53 IR transmitter. I'm facing some range problems particularly for three reasons: The HX-53 is supposed to be driven with 5 V. There is an LED in ...
user217354's user avatar
0 votes
1 answer
262 views

Using a Relay Driver with SRD 3V Relay

Short Version: How to connect (Which Terminals Go Where) the following two components DRDC3105 (A relay driver) SRD 03VDC SL C (A 3V relay supposed to control the flow of 230V AC and controlled by ...
Thuva Sooriya's user avatar
0 votes
2 answers
214 views

How to read the SN74LVC245A datasheet

I'm looking for help with how to read datasheets. For the below application, specifically what in the datasheets is it that would help me choose between these components? (datasheet for SN74LVC245A.) ...
mozboz's user avatar
  • 101
4 votes
2 answers
2k views

UART isolation with opto-coupler

I've got two devices running on different power sources and different grounds. I'd like to connect them together through a Serial connection (UART TTL) at baud rate 460800. Both devices have 3.3V UART ...
Manitoba's user avatar
  • 223
1 vote
2 answers
620 views

Serial isolation with 6N137 opto-coupler

I have two Raspberry Pi that I'd like to connect together through a serial interface. I've spotted the 6N137-L which can work with 3-5 V input voltage. I can connect it to the 3.3 V or 5 V GPIO pins ...
Manitoba's user avatar
  • 223
0 votes
0 answers
145 views

How to connect a 5volt relay to esp32?

Sorry to ask this stupid question here. I have the relay shown below with me. its a 5 volt relay. I wonder can it operate on 3 volts. If so, is it possible to connect it to the esp32 3 volt output. or ...
Savad's user avatar
  • 123
0 votes
2 answers
585 views

DHT22 issues at 3.3V - What else could I try?

I'm attempting to use an DHT22 at 3.3V for a very low power application - remote sensor unit with a very long battery life. Currently it's on a naked breadboard with a 328p. At 5V in a spare arduino ...
user2702772's user avatar
0 votes
3 answers
54 views

IRLML9301PBF as high side switching for 5 V, 2 A load from a 3.3 V uC?

Circuit: simulate this circuit – Schematic created using CircuitLab I would like to cut off the power to my APA102-LED-strip during uC sleep - as the standby current of these strips is relative ...
Stefan Krüger s-light's user avatar
0 votes
1 answer
141 views

Can I power an MCU using a 3.3V AC/DC module converter?

I'm designing a board that will connect to 230V AC. I found some ready to use AC/DC modules that can output 3.3V DC Here's the list from Mouser. Can I power an MCU directly from this output?. I'm ...
MrBit's user avatar
  • 2,033
3 votes
1 answer
526 views

Review ESP12 standalone module schematics

I am currently building a private design project. For this I need an ESP12E. I try to get it running with only 3.3V (VIN on schematics). In addition, I would like to be able to program the chip later ...
dessi's user avatar
  • 87
1 vote
2 answers
500 views

Using MCU as a power switch to PC -- connecting the thing correctly

My LED strip projects are done and completed succesfully for now and I am back with a question regarding powering MCU when using it as a remote PC switch. So what I have so far: a Raspbi Pico W which ...
Niko Alanko's user avatar
0 votes
0 answers
489 views

3.7 to 3.3V regulation

I want to power up my ESP32 with LiPo battery. LiPo Battery has voltage between 3.7 to 4.2V and ESP32's operating voltage range is 2.2 to 3.6V (but I want it to be 3.3V) and it consumes around 600mA. ...
Mehdi Maazi's user avatar
1 vote
3 answers
1k views

Is it possible to increase the current of an Arduino Nano 3V3 pin without altering the voltage?

I am trying to use an ESP8266 with an Arduino Nano but I see that the NANO can not enough current for supplying ESP8266 from 3V3 pin. I think it is limited from the faactory. If I use the 3V3 pin RX ...
mehmet's user avatar
  • 1,139
0 votes
2 answers
972 views

ADS1115: Using 5V supply instead of 3V, do I need to increase the logic level signal from 3V to 5V?

I am using a microcontroller that has a 3.3V Logic level output. The microcontroller is connected to ADS1115 via I2C pins, and the ADS1115 can be powered with 3.3V or 5V depending on the range of ...
Sam Shurp 's user avatar
1 vote
1 answer
395 views

Can I directly connect a 5V DC device to the inputs or outputs of a 3.3V microcontroller that tolerate that voltage level?

I'm doing a project with a PIC32 that works with 3.3V and that has some terminals that are tolerant to 5V levels. I need to manage another device that has a UART at TTL voltage levels (5v). The ...
Fabián Romo's user avatar
3 votes
2 answers
125 views

3V3 PSU Redesign. Noise issues

Our initial design was using the TPS560430 chip as a step-down converted from a Vin of (12-16V) down to 3V3 with the 3V3 rail looking like this (Vpp is 120mV, sorry for the quality): Because of the ...
Alex's user avatar
  • 101
1 vote
2 answers
495 views

Non-inverting switching 24 V with 3.3 V signal using a MOSFET

We have a reset circuit used in a peak-hold amplifier. Under normal conditions, a capacitor on the peak-hold circuit is grounded by RST1 (see circuit). P0-0 is a fixed 24 V voltage from the supply. ...
user2668812's user avatar
2 votes
2 answers
195 views

Understanding a SMD Motor driver IC (heat dissipation and control)

I am designing a circuit to control a 12V, 3A electric pump. I thought the driver rz7899 is very handy. The datasheet gave me the following doubts. Is it ...
SKGadi's user avatar
  • 862
1 vote
1 answer
45 views

Can RFM98PW 3V3 Regulator Cause Heating

I'm using RFM98PW RF module that is supplied by 5 volts. This module has SX1278 on board which is supplied by 3V3. So there is a 3V3 regulator on board. As you can see in the diagram below there is a ...
hasan mert karabacak's user avatar
1 vote
0 answers
204 views

CAN Transceiver circuit problem with TJA1042T/3

I am a novice designer who recently started designing circuits. Using the STM32f407VGT MCU operating at 3.3V, using the CAN1TX(PB9) CAN1RX(PB8) pins, the circuit was configured by referring to NXP's ...
이동재's user avatar
0 votes
1 answer
2k views

stm32 nucleo 3.3V usage

This is probably an easy question. When using an STM32 Nucleo powered by a 5V power supply, can I use its 3V3 pin to supply 50mA? Or do I need to use for instance a 3V3 linear regulator attached to my ...
WillyBogard's user avatar
0 votes
2 answers
237 views

splitting ground plane

I have a 4 layer board, where I have a 3.3V STM32 and some 3.3V components, and also a 24V H bridge to drive a 24V DC motor. The board is supplied with a 24V DC power supply, the 3.3V is created by a ...
Marcell Juhász's user avatar
0 votes
1 answer
6k views

Raspberry Pi Pico 3.3V_EN pin control voltage inquiry

I am trying to turn on or off a Raspberry Pi Pico using a Raspberry Pi Model 3. The Raspberry Pi Pico seems to have a 3.3V_EN pin which is basically the 3.3V regulator enable pin (3V3_EN) pulled up to ...
Roger Dsuza's user avatar
0 votes
1 answer
933 views

How to choose a resistor value for Wheatstone bridge such that it is a balanced circuit?

I have a 3V sine wave input and I want to measure resistor precisely from 1 ohm to 40ohm. I have tried using Arduino to measure the resistor using voltage divider but it became obvious that I will not ...
Sam 's user avatar
  • 319
0 votes
1 answer
178 views

How can i turn a DPST button in to a DPDT?

How can i turn a DPST button in to a DPDT? I've replaced all the stock rocker switches in UTV, got all 14 of them done except for one all to Push Buttons. The push buttons are SPDT, "on/on" ...
Vince Sodini's user avatar
-2 votes
1 answer
830 views

Can I drive a motor directly with GPIO pins?

I have a Raspberry Pi Zero with a DC motor attached (directly) to gpio. According to the Raspberry Pi Foundation: The operating voltage of the GPIO pins is 3.3v with a maximum current draw of 16mA. ...
Blue Herring's user avatar
0 votes
4 answers
967 views

Convert digital 12V/7V inputs to 3V3 levels

I'd like to read the digital inputs of my alarm sensor into a microcontroller (mainly PIR and Reed switches). The alarm system and the sensors operate at 12V (actually a tad higher) and the MCU uses 3....
orange's user avatar
  • 111
1 vote
2 answers
586 views

Step up 3.3V to 5V and draw 500mA without a voltage collapse/break down

I would like to step up 3.3V from my power supply with the help of a dc-dc-boost converter to 5V and then I want to draw 500mA by placing a 10 Ohm resistor between the output-pin of the boost-...
playmobox's user avatar
  • 105
1 vote
0 answers
156 views

MOSFET for 3.3v MCU

I'm building a custom board with ESP32-WROOM-32E that can supply 3.3v trough the GPIO. I need to power a screen using 3.3v power. I'm looking for a way to power off the backlight using the GPIO pins ...
offgabriele's user avatar
-1 votes
1 answer
414 views

How to change breadboard power supply output voltage?

I recently bought a 3.3/5v power supply like this. I'm powering it with a fresh 9 volt battery and 9 volt to barrel connector cable. Right now, it's on 3.3 volt mode, and I have no idea how to switch ...
fatNinja_Cat's user avatar
0 votes
1 answer
120 views

Diode instead of LDO

For a cost sensitive application we need a 4V supply for a GSM module and a 3.3V supply for a STM32 MCU and couple of sensors. Would it be possible to use a diode like 1N4148 to drop from 4V to supply ...
EarthLord's user avatar
  • 597
-2 votes
1 answer
419 views

How to use the human body as a battery?

I was wondering if you'd be able to extract 5 volts (or even just 3) from the human body. I recently discovered in an experiment that just putting a wet strip of aluminum foil over your forehead can ...
Blue Herring's user avatar
2 votes
1 answer
298 views

Powering the Raspberry Pi zero from printer PCB

I want to convert my simple printer into a network printer with CUPS on Raspberry Pi. I tested everything with Raspberry Pi 4 and it worked perfectly. Now, I want to fit my Raspberry Pi zero inside ...
Zeeshan Dhillon's user avatar
1 vote
1 answer
242 views

Using the same ESP8266's GPIO for 3.3v and 5v

I am designing a pcb which should receive various types of sensors. The microcontroller is an ESP32 and the external input are RJ11 linked to I2C GPIOs of the uC. I have already planned a LevelShifter ...
Abdou Sy's user avatar
2 votes
1 answer
122 views

Driving a 5V LED on computer chassis with 3.3V

My add-in card uses a pair of pins to drive an external activity LED, with anode "provid[ing] 220 ohm pull-up to +3.3 V". However, the LED that I wish to drive with these pins, is designed ...
Kostya's user avatar
  • 23
0 votes
2 answers
385 views

3.3V Regulator Overheating

Here is my circuit For some reason my 3.3v regulator is over heating. The regulator is a TLV1117LV33. I've tried everything to try and debug the problem but can't seem to figure out what's wrong ...
Wezley's user avatar
  • 113
0 votes
1 answer
2k views

Connect two pins on AD009-01T without a relay

I have an IR chip where I want to shortcut two pins (PA2 and PA0) when told so by a 3.3V Arduino. I could do this with a sort of relay, but I want a better way. I thought, that one of the pins needed ...
Magnus's user avatar
  • 179
6 votes
3 answers
1k views

Change voltage without consumption

Is it possible to change voltage without consuming power? I have a 5V Arduino circuit that makes use of a wireless chip (NRF24L01) that runs on 3.3V. My current approach to get 3.3V out of a 5V source ...
Socrates's user avatar
  • 199
3 votes
3 answers
655 views

USB2 powering 3.3V at 500 mA

I have the above simple requirement, and I'm frankly astonished that I can't find it as a simple chip. My understandings: USB2 provides 5V on its power pins; USB2 assumes 100mA, but will provide ...
John Burger's user avatar
  • 1,493
0 votes
1 answer
80 views

Connecting a TCXO to logic buffer

I am trying to connect the O/P from TCXO (FOX Electronics FOX924B. 20 MHz, 2.5 PPM, 3.3 V supply, Output HCMOS VOL = 0.5 V and VOH = 80% of VDD) to 74HC240 buffer, which I am also running at 3.3 V. I ...
Ashok Das's user avatar
1 vote
1 answer
94 views

load resistor - my setup is valid?

i want to test my output current of transistor 2N3906. I have two questions. Is my setup valid to measure the max load of the (2N3906) transistor? One plug of multimeter is on leftmost pin of PNP ...
krg's user avatar
  • 39
0 votes
1 answer
517 views

My node mcu isnt turning on when connecting 3.3V to VIN [closed]

So I'm trying to wire my node MCU using in with 3.3V and in the multimeter, it's reading the 3.3V being delivered properly by the converter, I also tested for amperage and its consuming 37mA and I don'...
DeadSec's user avatar
  • 377
0 votes
2 answers
455 views

Power on/off 30-50mA module with 3.3V Arduino-like GPIO

In my Arduino 3.3V project I have a problem shutting down a GPS module. When it "sleeps" with a command, it comsumes 2mA which is way too much for my project. To my understanding I have to ...
krg's user avatar
  • 39
0 votes
1 answer
60 views

May I connect 3.6v Li-pol accumulator to 3.3v dc supply?

I have an old Bosch electric owen which has clock and timer on-board. The problem is: on each electricity fail (even milliseconds) this clock resets to the time edit mode and zummer starts to make ...
Epsiloncool's user avatar

1
2 3 4 5 6