I have replaced these in modern dehumidifiers (GE, Honeywell etc) and portable air conditioning units. These are used to drive relays to actuate the compressor, fan motor and other devices that I can't think of at the moment. This makes me believe that they are still commonly used today.
Useful chips, used in printer for pin driver, also great for stepper motor drive. Where logic meets the outside world, 7-segs, lamps, motors, etc. Good thing about is output isn't a perfect 'on' which is handy.
If i recall correctly, you can parrallel 2 inputs/outputs for 600+1A output. Used it to drive some leds on a fishtank triggered from an esp32. Was overkill but the ic is a nice form factor.
Awesome. I've seen these in a few control boards in the lab equipment I work on (incubators, glassware washers) driving motors, relays, solenoid valves. I keep a few on hand as well. I had one of these fail once in a glassware washer - attempted to power it on and every single output device (wash pump, blower, valves, etc) was turned on momentarily in a loud crescendo and then the magic smoke was released.
One of my favourite ICs. Stable, predictable, great protection, daisy chain outputs for bigger current. I think I’ve done a couple of vids on these now. 👍😀
Ah the ULN2003, pretty popular and useful. Combine that with a numitron / minitron (segmented incandescent display) or even some bulbs or strings of LEDs in a larger 7-seg... driving it from a 7448 etc. BCD to 7seg decoder, common cathode. I prefer the 2803 though, one of my to-go chips whenever you need to drive some relays, solenoid valves etc. Two of these combined with a MCP23017 (I2C) or 23S17 (SPI) are a mighty useful combination, 16 open collector channels... and you can scale that up to 8 23017s on a single bus. That's what made the rpi2caster project (controlling a Monotype composition caster with a Raspberry Pi) possible.
Back in the day they were maybe more useful but they lack output protection and have a high saturation voltage so I wouldn't use them today to drive high current loads, there are protected drivers available
For nixies etc. there's a high voltage BCD decoder in one of the two classic logic series . There's also 7446 for higher voltage 7-segment displays, though still not for the old NASA countdown sign at KSC (now replaced with a giant video screen).
Useful part... but i never used one of them - always discrete Transistors, that is what i do a lot. Perhalps this is because when i started electronics those IC have been hard to find and expensive while simple transistors like BC337 / BC327 every small electronics shop around had in stock at a reasonable price...
Yes, but in the 80s and even 90s we only had some tiny shops and classic mail order catalogs with mostly high postage costs and minimum order quantities and complicated payment because they were abroad 😕@@onecircuit-as
We just had a new heat pump unit installed to replace the old compressor of the ac unit for our house and the controller board has a bunch of ULN2003 on it
Love this ICs. Use them to drive relays all the time. Very stable and reliable, can drive directly from any 3.3v or 5v signals.
I have replaced these in modern dehumidifiers (GE, Honeywell etc) and portable air conditioning units. These are used to drive relays to actuate the compressor, fan motor and other devices that I can't think of at the moment. This makes me believe that they are still commonly used today.
Useful chips, used in printer for pin driver, also great for stepper motor drive. Where logic meets the outside world, 7-segs, lamps, motors, etc. Good thing about is output isn't a perfect 'on' which is handy.
If i recall correctly, you can parrallel 2 inputs/outputs for 600+1A output. Used it to drive some leds on a fishtank triggered from an esp32. Was overkill but the ic is a nice form factor.
Awesome. I've seen these in a few control boards in the lab equipment I work on (incubators, glassware washers) driving motors, relays, solenoid valves. I keep a few on hand as well. I had one of these fail once in a glassware washer - attempted to power it on and every single output device (wash pump, blower, valves, etc) was turned on momentarily in a loud crescendo and then the magic smoke was released.
Also a good way to run a bunch of relay switches with your IC
I have used these in many ATE designs to drive relays.
Thanks for this video. I have three tubes of these in DIP and couldn't quite figure out a good use case.
One of my favourite ICs. Stable, predictable, great protection, daisy chain outputs for bigger current. I think I’ve done a couple of vids on these now. 👍😀
Ah the ULN2003, pretty popular and useful. Combine that with a numitron / minitron (segmented incandescent display) or even some bulbs or strings of LEDs in a larger 7-seg... driving it from a 7448 etc. BCD to 7seg decoder, common cathode.
I prefer the 2803 though, one of my to-go chips whenever you need to drive some relays, solenoid valves etc. Two of these combined with a MCP23017 (I2C) or 23S17 (SPI) are a mighty useful combination, 16 open collector channels... and you can scale that up to 8 23017s on a single bus. That's what made the rpi2caster project (controlling a Monotype composition caster with a Raspberry Pi) possible.
theses and LM759 made great radio and headset interfaces for audio and PTT 's etc.
Can be used for dynamic 7segments indicators to replace a bunch of bjt-s and easy to trace route.
I used it a many time back at the days.. for buffering microcontroller output to relay.
Back in the day they were maybe more useful but they lack output protection and have a high saturation voltage so I wouldn't use them today to drive high current loads, there are protected drivers available
For nixies etc. there's a high voltage BCD decoder in one of the two classic logic series . There's also 7446 for higher voltage 7-segment displays, though still not for the old NASA countdown sign at KSC (now replaced with a giant video screen).
You do need to watch the power dissipation: 500 mA x 1.2 V = 600 mW and SOICs can only dissipate < 3W under the best of conditions
I love chip of the day!
3:19 ULN2803 has 8 outputs, so you can do something like byte output.
I'm guessing that's an 18 pin device?
There is an eight channel version available as well - ULN2803CDWR is a typical number..
Useful part... but i never used one of them - always discrete Transistors, that is what i do a lot. Perhalps this is because when i started electronics those IC have been hard to find and expensive while simple transistors like BC337 / BC327 every small electronics shop around had in stock at a reasonable price...
AliExpress - still cheap & available 👍😀
Yes, but in the 80s and even 90s we only had some tiny shops and classic mail order catalogs with mostly high postage costs and minimum order quantities and complicated payment because they were abroad 😕@@onecircuit-as
@@tvelektron I remember - frying something accidentally was less fun that's for sure!
The BC337 is my go-to small signal transistor. Very robust and will replace most other small-signal transistors within reason.
I've been told that these were originally developed to drive the solenoids on dot matrix print heads.
Just so you know, the audio on this video is panned right again.
I know, I do not release in the order of editing. it will clear up eventually. sorry, I know you just were warning me, thanks!
We just had a new heat pump unit installed to replace the old compressor of the ac unit for our house and the controller board has a bunch of ULN2003 on it
Great chips…. Still use them all over.
Wonderful IC. Been using them for nearly twenty years and never had a failure (touch wood). You can also OR the outputs together (open collector).
My ULN2003A #14 leg has burn through, likely water got in.
Do you think this has to do with my electric oven auto automatically turn on
The 8 chan version is better for 8 bit computers to control things.
Definitely! I used these in my rpi2caster project.