161 Threads found on edaboard.com: uln2803
Please specify that where can I find serial uln2803 type ICs?(with short circuit protected output power transistors,if possible)
Professional Hardware and Electronics Design :: 18.07.2003 13:30 :: 7rots51 :: Replies: 5 :: Views: 1822
I've been used it very times.
And I want find a inverting of uln2803
- uln2803 is NPN darlington.
- I find PNP darlington
Seem I post wrong topic. Sorry
Hobby Circuits and Small Projects Problems :: 08.09.2004 04:32 :: conkhicon :: Replies: 1 :: Views: 1370
i have 2 boards
2.74HC595 -> uln2803
the connection is 2-3m /~5ft/ the system is work good but in one moment stop, i put a control LED on one of the ports to seen is the controller work . the controller work but no reaction on other board
may be the problem is in cable or signal level :((( can some help me
Microcontrollers :: 12.08.2006 08:28 :: syrax :: Replies: 1 :: Views: 2371
i would suggest uln2803, coz it contains 8 current drivers so overall u'll need 2 uln to for this. Most of the 8x8 LED arrays will have 16 pins( 8 anode connection and 8 cathode connection) by giving proper signal u can glow a particular LED.
Buffer must be placed between ULN and controller in order to protect the controller. By giving correspondi
Electronic Elementary Questions :: 12.02.2007 07:21 :: brahma :: Replies: 2 :: Views: 3913
I'm making a stepper driver with uln2803. It's working, but the IC heats up very quickly. I'm not using microstepping. I'm using two outputs paralleld together, totaling one ULN IC per driver (8 outputs / 2 = 4 outputs, as needed for uniploar driving).
Is it safe to operate the ULN in high temps?Or should I get some cooling? Is there cooling for
Hobby Circuits and Small Projects Problems :: 26.09.2007 17:08 :: izua :: Replies: 3 :: Views: 2439
I think I must connect Vcc=5 Volt on the Common pin, that is Pin number 10.I don't understand the concept of diode as shown in the diagram. It seems like as if it's working like a pull up resistor. I also don't understand the other two diodes drawn in a dashed lines (- - - - -). By studying various other examples on uln2803, I hope to learn how thi
Microcontrollers :: 13.07.2008 11:56 :: umery2k75 :: Replies: 11 :: Views: 16187
In my design,I try to use AT89S52+uln2803 for Led driver.Could I connect port 1(or 2,3) to 2803 without any pull-up resistors?
Someone said port1(or 2,3) can not output 1mA current.But I can not find the parameters on the datasheet.
Professional Hardware and Electronics Design :: 15.07.2008 03:24 :: dwep :: Replies: 3 :: Views: 4872
i am working on uln2803 to drive my DC is supposed to get an inverted o/p at its o/p pin i.e When I am giving an logic low input i must get an logic high output...but my outpin pin is always giving an low signal irrespective of my i/p signal.I have pulled up all my inputs.Please help me to find a soln 2 this probl
Microcontrollers :: 22.10.2008 10:02 :: vikky :: Replies: 6 :: Views: 1456
have you guys tried using uln2803 as driver for 74LS595 for use in LED matrix
what do you want to ask??? your desire is not so clear?????????/
Microcontrollers :: 20.02.2009 15:26 :: sn_burki :: Replies: 5 :: Views: 3221
Hi, anyone can help me how to use uln2803 to drive Relay.
I use uln2803A and my coil relay is 12VDC. COM on the pin no 9 should be connected to 12v or 5v? and uln2803 doesn't have VCC pin.
Please help me if possible in a diagram.
Microcontrollers :: 16.08.2009 05:36 :: philips1983 :: Replies: 1 :: Views: 6587
From My SBC Board supply of +3v is coming and External Device need 12votl supply can I use uln2803 between board and device as a Voltage convertor??
Hobby Circuits and Small Projects Problems :: 20.08.2009 02:00 :: dinesh.4126 :: Replies: 16 :: Views: 7307
I have a pcb which is using pic16f72 and uln2803 for stepper motor control. I need a program for this circuit and schematic. Can anyone help me please. I searched over net but i could not able to find
Actually i have bunch of (10 to 15) steppers from old printers, i want to test them and use it for robotics. So i can use this circuit
Microcontrollers :: 05.12.2009 13:22 :: imported_robotsmani :: Replies: 0 :: Views: 1158
the gnd pin of this chip uln2803
can i ignore it or hook it to the gnd?
in proteus, this chip has no such pin
i wonder in real circuit if i should connect it to the ground.
Microcontrollers :: 14.01.2010 04:14 :: newbie111 :: Replies: 3 :: Views: 757
Some suggestions about your schematic design :
Use uln2803 output in open colector the LED with your relay.
PCB Routing Schematic Layout software and Simulation :: 31.05.2010 13:31 :: sokrad :: Replies: 2 :: Views: 12593
I needed help on using uln2803. Like i wanted to drive some relays using uln2803. So how should i configure the uln.
The condition is i want to ouput 12 from uln2803. I have provided ground to 9th pin and 12vcc to 10th pin. Now if i provide ground from microcontroller circuit. to input pins (i have shorted the ground from microcontroller (...)
Analog Circuit Design :: 10.05.2011 07:43 :: prathyks :: Replies: 3 :: Views: 1415
uln2803 is an octal current sink. You can use it to interface to 12V but it will invert the signal and need it's outputs pulling up. Unless your PLC needs high currents at it's input you would find it better to use an open collector logic buffer such as the 74LS07. Unfortunately that device only has six buffers but you could use more than one or bu
Hobby Circuits and Small Projects Problems :: 25.07.2011 15:27 :: betwixt :: Replies: 4 :: Views: 2466
how can i connect the output of IR Receiver to input of p89v51rd2 microcontroller and output of microcontroller to drive a uln2803.if i connect output of ir receiver(4.94v)directly to my microcontroller pin,will my microcontroller work?
and one more thing,can i connect microcontroller output directly to uln2803
Electronic Elementary Questions :: 06.11.2011 13:57 :: navneet sngh :: Replies: 8 :: Views: 1173
This project may help a new hobbyist to understand how to interface uln2803 with PIC micro to control loads up to 500mA with schematic, picture and video.
Please refer to uln2803 datasheet at
Here the given code will drive 8 lines of LEDs to produce few fascinating designs.
Microcontrollers :: 20.11.2011 03:25 :: papunblg :: Replies: 2 :: Views: 1231
My question is can we stack two or more uln2803 ICs on top of each other(i.e. in parallel) to increase the max current capability? I want around 600mA in each of the 8 channels at 50% duty cycle (to drive two steppers in full step mode).
Thanks in advance!
Analog Circuit Design :: 30.12.2011 04:46 :: robert576 :: Replies: 1 :: Views: 374
Hi i want to use a pic microcontroller to control an array of 50 leds. I'm using two uln2803 ICs to control the anode and cathode of the leds but
i'm having problems with my schematic because uln2803 is a NPN transistor array and i can only sink the voltage and not supply it. Is there any PNP array
Microcontrollers :: 31.12.2011 12:41 :: georgz :: Replies: 7 :: Views: 1262
Your schematic lacks sufficient detail.
The following is an example Relay to uln2803
I have also attached a PDF for a 4 Relay Board using a uln2803 which has a schematic.
Professional Hardware and Electronics Design :: 21.04.2012 01:25 :: bigdogguru :: Replies: 7 :: Views: 3289
can i use a uln2803 (50V, 500mA per channel) to drive a 1.5A per phase stepper motor without load ?
Power Electronics :: 06.09.2012 12:31 :: varunme :: Replies: 3 :: Views: 500
I have used UDN2981 in my project to drive 4 seven segment displays, 2 big LED's & 1 buzzer. The Vs pin(9) is connected to 5V supply of micro-controller. Resistors for displays & LED's are chosen accordingly.
Now my problem is that the sound from buzzer is not enough on field. I will have to increase the supply of the buzzer (it can work from 3V
Professional Hardware and Electronics Design :: 20.09.2012 04:44 :: vbdev :: Replies: 2 :: Views: 924
NO ! you cannot use a uln2803 for controlling a mains triac there is no isolation, use a proper opto isolator, many circuits around.
Microcontrollers :: 12.12.2012 04:40 :: wp100 :: Replies: 1 :: Views: 382
Connect input drive signal to uln2803 input pin. Connect lamp between the corresponding output pin and +V. Connect pin 10 (COM) to +V. In Proteus, the common emitter pin of uln2803 is hidden and is connected to ground.
By the way, for driving a single lamp, you can just use a transistor. You don't need to use uln2803.
Hope this helps.
Microcontrollers :: 14.12.2012 07:01 :: Tahmid :: Replies: 3 :: Views: 791
In simple words, uln2803 is an inverting open collector driver. You can connect an external inverter to make it non-inverting, but you can't make it drive active high.
Depending on your application, a pull-up resistor might be sufficient to achieve push-pull operation. Otherwise I suggest to design a suitable driver circuit on the transistor lev
Analog Circuit Design :: 28.03.2013 03:53 :: FvM :: Replies: 2 :: Views: 447
can u help me to choose my driver to control a unipolar stepper motor. wath is the best choice, uln2003A or uln2803 ???
Microcontrollers :: 20.04.2013 17:09 :: Tiabak :: Replies: 1 :: Views: 222
uln2803 is a darlington driver. It can't achieve 0.1 to 0.2 V saturation voltage.
Analog Circuit Design :: 12.06.2013 08:26 :: FvM :: Replies: 3 :: Views: 214
You can use ULN2003 or uln2803
Professional Hardware and Electronics Design :: 06.06.2002 17:19 :: 7rots51 :: Replies: 15 :: Views: 8390
use the old tl084
it has 4 op amps and works rail to rail on 5 volts
just divide your input voltage. you may add filtering also.
For signaling i normaly use a uln2803 with a diode to
sense on/off inputs
Professional Hardware and Electronics Design :: 13.06.2002 20:23 :: padspcb :: Replies: 12 :: Views: 2363
I have used 89c2O51 for this purpose. The port 1 drives the segments through a uln2803 (or ULN2003 if no decmal point is needed). For driving teh digits, I use 3x74LS138 and BC557 transistors. I think this is the cheapest solution that can be made for this purpose.
Professional Hardware and Electronics Design :: 22.12.2002 10:20 :: techie :: Replies: 16 :: Views: 2333
I want to replace a Siemens PLC by a microcontroler. For the 24V output I'll use some classic drivers like uln2803.
Can somebody give me some tips and/or diagram to obtain the same reliability as professional PLC.
What kind of components I have to use to proctect for example from HVoltage spikes, short circuit, reverse current....
Professional Hardware and Electronics Design :: 28.02.2003 04:00 :: mdamdam :: Replies: 7 :: Views: 1683
My avr micro 8515 on/off a relay by a uln2803 driver,when relay have no load everything goed well,but when I attached a 100w lamp as load to relay contacts the avr resets when turns the lamp OFF.
I used the snubber circuit across contacts but problem remains.
Please guide me.
Analog Circuit Design :: 10.01.2004 13:51 :: 7rots51 :: Replies: 5 :: Views: 2705
I found also a chip to do that
Professional Hardware and Electronics Design :: 08.04.2004 02:53 :: SphinX :: Replies: 5 :: Views: 1032
What is the best way to interface a 3V microcontroller to 15V CMOS ?
is it possible to use uln2803?
Microcontrollers :: 25.05.2004 02:02 :: mystery :: Replies: 7 :: Views: 1349
You can also use such darlington array : = t
Analog Circuit Design :: 11.08.2004 04:11 :: papyaki :: Replies: 2 :: Views: 859
Great. Why dont use the power supply from the printer itself? Also, u can try uln2803 type of things instead of transitors.
Hobby Circuits and Small Projects Problems :: 09.09.2004 04:48 :: asit :: Replies: 6 :: Views: 1007
I am a total newbie in HDL :oops:
But now i might have a thing where a CPLD could come in handy
I have gotten some 8x8 LED blocks Red/Green (See attached DS)
And i would like to build a display with 8 of those blocks , and control them with an Atmel Mega16 or Mega32.
Each 8x8 block have 24 pins so its 8 x 24 pins in all.
PLD, SPLD, GAL, CPLD, FPGA Design :: 17.12.2004 14:30 :: Bingo600 :: Replies: 1 :: Views: 923
as far as I remember the 8051 has a weak pull-up current source of about 100uA at his ports. It is not able to drive a uln2803! You will need an external pull-up resistor. The current consumption is to high for more channels.
An external FET is only a solution if it is a logic-level FET ! You need a flyback diode.
The best way is to use a intell
Electronic Elementary Questions :: 29.12.2004 09:58 :: felix1200 :: Replies: 14 :: Views: 5239
What is your load ?
Why not use BC337, 2n2222, uln2803, or L293... ?
Professional Hardware and Electronics Design :: 25.01.2005 21:52 :: manu :: Replies: 7 :: Views: 2149
How big is maximum current per pin? In LVTTL it is said +/-24mA minimal. For testing purpose I want to connect LED diodes to FPGA structure, but there is no documented limitation of safe maximal current per pin (it is no so important) and per port (it may be important, because whole current goes thru Vcco pins and ground pins). So is there any limi
PLD, SPLD, GAL, CPLD, FPGA Design :: 16.02.2005 19:05 :: elektryk :: Replies: 2 :: Views: 591
try using uln2803 driver IC , u could use two or after the 2803 u could connect a D313 transistor, capable of driving upto 2Amps.
Microcontrollers :: 22.11.2005 12:03 :: snabilat :: Replies: 9 :: Views: 1038
CD4050B it's not able to provide the requested source current for multiplexed LED display, even if the gates are parallel connected.
You must use either 16 NPN transistors or one uln2803 (as suggested by HUGo, driven by port P1 outputs) and 8 NPN transistors for rows.
and obvious 8 resistors for current limiting (a value of 220R would be fine).
Microcontrollers :: 04.02.2006 18:46 :: silvio :: Replies: 12 :: Views: 3624
I use proteus 6.2 sp5 to make my schematic diagrams.I am new to the program. I wanted to ask what should I do about devices which are not available in the library. For example uln2803 is not in my library but ULN2003 is. How can I add uln2803?
PCB Routing Schematic Layout software and Simulation :: 16.02.2006 13:02 :: ibrahim03 :: Replies: 2 :: Views: 2788
I agree that 2N7000 or BS170 (TO-92) or 2N7002 (SOT-23) make good low current low side switches.
Also consider uln2803 8-bit parallel sinking driver or MIC5841A serial-to-parallel 8-bit sinking drivers.
Good luck. Regards, Mike
Microcontrollers :: 17.07.2006 21:34 :: Mike, K8LH :: Replies: 6 :: Views: 8566
I just want to ask if this chip a stp16c596 is capable of running a dual color matrix located at the bottom of page by it's self in place of 2 74hc595 and 1 uln2803 to run it.I'am not too good with the datasheets and i'am unsure it can handle the current properly.I want to make a moving display with 8 or 10 of these matrix's and the fewer chips the
Hobby Circuits and Small Projects Problems :: 23.08.2006 14:45 :: bbarney :: Replies: 4 :: Views: 1954
h ehe he he eh !
The current need big or small ??? If big, you should use buffers as Darlington as uln2803, . . . . . and if small, you can use 4N35 (<50mA).
Good luck for U !
Analog Circuit Design :: 30.10.2006 21:17 :: KST :: Replies: 6 :: Views: 3969
I'm using a uln2803 in SO18 package. Need to use ULN2805 instead (3.3VDC). Does anyone know where I can find it ?
Or any better idea to drive 8x 12V relays with 3.3VDC.
Professional Hardware and Electronics Design :: 11.12.2006 17:11 :: BEA :: Replies: 3 :: Views: 1752
i was thinking of making each segment driveable by a transistor.
Use uln2803, you can drive until 300 mA each segment without any problem. Less component, more realible.
Hobby Circuits and Small Projects Problems :: 13.12.2006 10:05 :: budhy :: Replies: 2 :: Views: 903
Why not use ULN2003 or uln2803?
Microcontrollers :: 04.02.2007 01:09 :: clairvoyant13 :: Replies: 5 :: Views: 2181