JUNKYARD SCAVENGING NETS A TACHOMETER TO play with

We never believed to hit the automotive junkyard to discover electronics we might play with. however [Istimat] was able to pull this working tachometer from an otherwise destroyed motorcycle dashboard. The Kawasaki part has just three pins on the back of it. By linking 12V to the IGN pin, ground to GND, as well as tapping a 12V cable on the unlabeled pin he was able to make the needle dance as well as understood he was getting somewhere.

His microcontroller of option for the job is an Arduino board. however the 5V logic levels aren’t going to put out the square wave needed to drive the device. A browse of the Web led him to a 2-transistor circuit which lets him get the results seen in the video. His plan is to add performance that utilizes the Arduino to pull data in from just about any type of source as well as screen it on the dial. That computer desk that featured all the CPU tons readouts immediately concerns mind.

Do you believe the square wave circuit is much more challenging than necessary? might this be finished with just one NPN transistor as well as a pair of resistors?