Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [uln2003]

35 questions
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votes
2 answers

Water level indicator using ULN2803

i made an water level indicator using IC: ULN2803 Refer: Easiest water level indicator It works well when used on glass of water, but when connect to my rooftop tank all the leds slowly diminishes and turns off. I think this has to do with high…
Alex Robbin
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1 answer

ULN2003 low-side switch electrical characteristics

ULN2003A So I'm currently exploring low side switches. I started off with an NMOS transistor array IC (Open drain), to develop a better understanding I've tried to understand the Darlington transistor array (Open collector) implementation as well. I…
Harkirat
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2
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1 answer

ESP32 LED driver circuit

Is there anything majorly wrong with the below schematic? I'm still learning and I have followed the datasheet but feel like I'm missing something.
robbrown92
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3 answers

ULQ2003 not driving a Relay properly

I am driving a 9V DC (5 PINS) Relay from darlington array ULQ2003. The ULQ2003 COM pin is connected to 9V power supply while the Relay coil is connected to +12V supply. The Ground of both are connected together. When 'OUT1' is at LOW then the Relay…
alt-rose
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3 answers

Controlling Solenoid Valves with ULN2003A, Inrush Current, Arduino

I want to control a total of five solenoid valves with my Arduino. The solenoid walves operate at 12 volts and have a power consumption of 5 watts per solenoid valve, which equals a current of roughly 420 milliamps. My idea is to use a ULN2003A…
Chris1309
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2 answers

Can I use a ULN2003A IC as many transistor switches?

I want to make home automation using Arduino. Instead of relay modules, I prepare my own relay module using relays and transistor switches, in between the Arduino and relays. I want to make many transistor switches. Instead I planned to use IC like…
Nifty 17
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Is it must to have freewheeling diodes for ULN200x when used with dc motor?

I need to eliminate the MOSFET drive circuit from my PCB by replacing uln2004 or uln2803, should I still keep the back EMF diode across the dc motor? motor supply 5V current 70mA
oppo
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ULN 2003 open collector

I have searched for troubleshooting the ULN and did not find any solution. I use a ULN chip in a motor inverter for controlling precharge relay and main relay. The problem is when the motor inverter is powered off, and for instance the charging is…
Johannes
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ULN2003 Saturation Voltage help

I'm busy designed a PCB that will use a Raspberry Pi's GPIOs to to drive several optoisolators. Additionally I'm also interfacing with an IO module that works with HIGH > 1V. Because of the number of optoisolators I'm using I don't want to overload…
riaanc.
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ULN2003 current flow through non enabled pins

Edit: solution found There was some amount of flux residue remaining on the board from when I soldered it. My meter didn't beep in continuity mode, but it did register some resistance, which I didn't notice at the time of soldering because I was…
MKUltra
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Driving solenoid valve using LM358 as comparator and ULN2003

I'm trying to drive a 12V DC solenoid Valve with following diagram. In 1st block the PC input is compared with 2.2V and its output goes to block2 and ULN2003 for driving the valve. The 2nd block is a pulse generator which is used to drive a Buzzer.…
Mehran
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1 answer

MCU to switch single coil latching relay not working (attempting array with common gnd)

I have several single coil latching relays, (low rep points so not hyperlinking), mouser.com/ds/2/212/KEM_R7002_EC2_EE2-540906.pdf (EC2-5SNU). I am trying to control them by an MCU; connected directly they work fine, but I am iffy about keeping it…
Orbitronics
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3 answers

Explanation how uln2003a works

This is a schematic for the an internal input/output pins of an uln2003a and other such array transistor. From what I understand, when no voltage is present on the first transistor, the current will flow from Ouput C to E or Ground. Here I'm, not…
Loïc Faure-Lacroix
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Multiple Voltages for ULN2003

I am using a ULN2003 to power lamps and LEDs, and controlling them via 5v TTL. I have some LEDs can be driven by 5v, and some lamps which require 12v. Using the same ULN2003, can I have some powered with 5v, and some 12v, or do I need to use 2…
Fed
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Stepper motor control - full step not working

I am using a ULN2003 to control a unipolar stepper motor from my PIC18F45K20. When I only connect one 12 V power cable (Red), the stepper motor works in full step, however, when I connect the other 12 V cable the motor stops and emits a high pitch…
Matthias
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