Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Wanting to build a light bar replacing tach

Status
Not open for further replies.

badattitude

New Member
Does anyone know how to build a light bar, maybe 10-20 lights that would replace or work along with the regular tach. I have a modified pulling truck and would like to be able to see the rpm from outside the truck. I have a msd 7al ignition and I am thinking I could get a signal from it. Any help would be appreciated. Remember I am a novice when it comes to electronics.
 
Use an LM3914 ic. It is designed for the kind of thing you want to do and there is heaps of circuit ideas on the 'net for using it. They can be stacked up to 100 LEDs and each chip drives 10 LEDs.

Try Google LM3914
 
Remember I am a novice when it comes to electronics.

Yep, just use a 16F84. All you need to do is learn a programming language and the 16F84, then work out a multiplex system to run 20 LEDs from about 10 I/O pins and there you go......

Google LM3914 tacho, rev counter. An LM2917 will give you frequency to voltage and the LM3914 will do the cascade bar graph stuff. Or check out the National Semiconductor web site.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top