driving relays with little power (4017IC)...tips?

Thread Starter


Joined May 15, 2010
Hey guys, I'm working on a simple circuit. Here's the gist of it: I want to hook up a 4017 IC (used in chaser-circuits) and upon each output going HIGH, I want to activate a relay and pass 12V from a low-grade car-battery through it. The circuit itself is easy; I've made chasers using the 4017 IC before and am well-versed in relays. My problem is that I'm pretty sure the 4017 doesn't have the power to switch an relays. (perhaps a solid-state relay would work?). But I was wondering if anyone had any tip for this. Perhaps some type of driver or bi-lateral switch that would control a very large output from a very small input. From looking at the datasheet, the 4017 outputs a voltage near the supply voltage, but only about 4mA of current. So that's the situation. Any tips would be appreciated. Thanks. -Joe


Joined Dec 5, 2009
Thats about it.

You could use a relay with a 5v coil, and a transistor or 2 (DARLINGTON PAIR) from the 4017 to the relay coil.


Joined Jul 17, 2007
The DS2003 is a National Semiconductor specific part number for the industry standard ULN2003 7-channel Darlington driver array.