Optical Rev Counter

Hi guys, I been given an electronic project to make an optical rev counter for a RC airplane. If anyone has any experience with makeing one i'd really appreciate any help or links to information or schematics. I really can't seem to find any information about this on the net.

Hi guys, I been given an electronic project to make an optical rev counter for a RC airplane. If anyone has any experience with makeing one i'd really appreciate any help or links to information or schematics. I really can't seem to find any information about this on the net.

To make one or design one? The difference being significant if you are working on an engineering degree. If you are, then you need to analyze your project and design it yourself not copy someone else's design. That does you no good at all.

Think about it. Break it into small chunks that need to be done. Then do those chunks one by one. I'm retired from electronic engineering and design having at one time 50 engineers in my employ in my company. I'd advise you to create your own means to accomplish your goal if you are studying to become one. Seriously.

Design your own. Think. Experiment. Try different approaches. Create. You'll be worth 10 times what you'd be worth if you copy someone else's design.

-- Ray

Consider using a microphone to pick up the exhaust note. Clean up the signal, get something you can trigger off of, and.......... You could do all that without IC's.

If you want an analog RPM (engine speed) indicator, you still could do it without IC's...... An RC circuit will give you an analog voltage varied by frequency. An actual counter though, you'll need some IC's.

Did you miss the part where he was required to make an optical rev counter?

-- Ray

Duh, yup, yup. Sure did.

I'll go find a hole now.

"spiral_72" wrote

As in, "the way to get out of a hole, is to stop digging-first!"

Do you want us to do your homework asignment or point you to one of several paths to a working instraument?

Done this project several times for RC

Analog or digital read out?

Mim & max RPM?

Airborne or on the ground or data logger?

Max Weight?

Max electricial power available?

Then we can talk about the actual design anddraw circuits.

As far as actual designs search for ProTach which was kited by Royal Electronics of Denver CO in the 1980's. May have been published in RCM.

Tomorrow when I am at work I will look for my DigiTester opticial tach design from the same time period. If I can get a good enough scan to put up on our web site I will post the URL tomorrow.

Hugh

Greetings

I just redid the DigiTester optical tach schematic in Eagle Cad.

The schematic file is located at

Click on the links page and the schematic file is the last option at the bottom of the page. It is a *.sch Eagle schematic format. Get Eagle 4.xx at

If I bring this up to date it will use a PIC for a gate logic, counter, time base and a LCD display. The original used a LED display and a now out of production counter chip.

The original DigiTester did servo pulse with 1.xxx second resolution. Also could measure servo pulses out of the receiver. Included a 19.99 voltmeter and the optical tach.

Thinking about adding servo current measurement to the new project.

Hugh

snipped-for-privacy@gmail.com wrote: