# darlington array question

Joined Oct 4, 2013
472
hello all... Im sort of new to electronics with a very knowledge. I can read schematics and assemble basic circuits.. Im just now truly learning transistors, I have a fair understanding of resistors and was just taught a lesson in leds in my first post here.. I like to reuse scavenged electronics from old broken things I find.. I recently found a darlington array chip and after searching the net for a datasheet, I learned that it is essentially just 7 transistors in on piece... Being a newbie and wanting to learn as much as I can I was hoping someone might be able to suggest some newbie project I can do to help me understand how to use this and learn how to identify the need for it in future projects of my own..

#### ScottWang

Joined Aug 23, 2012
7,414
According what you described that it seems like as ULN2003, also the ULN2803 is 8 darlington pairs, the total Imax=500mA, whatever you are using anyone or total 8, they all can providing the same current.

But for the heat and the products using life, so you better using it less than 1/3 of 500mA, it will be about 166.667mA.

Joined Oct 4, 2013
472
According what you described that it seems like as ULN2003, also the ULN2803 is 8 darlington pairs, the total Imax=500mA, whatever you are using anyone or total 8, they all can providing the same current.

But for the heat and the products using life, so you better using it less than 1/3 of 500mA, it will be about 166.667mA.
Its uln2003a.. I googled a datasheet and it said its a 7 pair darlington array... im not quite up to speed on transistors and am looking for a simple project to understand the use of this.

Joined Jul 18, 2013
28,831
Did you want a project to enable you to use the ULN2003 or did you want a break down of what a Darlington is?
A typical use of the arrays is to transition from TTL to say higher current 24vdc operating devices.
Or stepper motor driver etc.
Max.

Joined Oct 4, 2013
472
Did you want a project to enable you to use the ULN2003 or did you want a break down of what a Darlington is?
Max.
I have a problem learning from technical explanations and ive read the datasheet and other explanations on the web.. The only way I can learn is from hands-on doing.. So what I really want is a small basic project using one so I can learn from it as I build it... I just don't want to burn it up not knowing how to use it.. I don't care if its lighting up leds, I just want to learn how it works by using it.. Ive read something like it multiplies voltage or something.. maybe something where I can meter the output to understand how it does that..

Joined Jul 18, 2013
28,831
You could just use a switch on the input side that sets the input from a 5vdc supply and place a LED with a series resistor using say a 12vdc supply and switch the LED on/off on the related output.
http://digital-diy.com/general-electronics/101-tip-uln2003-high-power-driver.html
This shows a Micro but you would substitute that with a simple on/off switches and LEDs with suitable resistor on each darlington..
Max.