Digital automotive tach circuit?
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From: Noozer on 28 Oct 2006 17:56 Anyone have a simple digital tachometer schematic handy? I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine. Fed by the TACH output of a six cylinder GMC on distributor coil. If it isn't much more difficult, I'd like to be able to drive a bar graph of 12 to 16 LEDs as well.
From: BobG on 28 Oct 2006 19:40 Noozer wrote: > Anyone have a simple digital tachometer schematic handy? > I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine. > Fed by the TACH output of a six cylinder GMC on distributor coil. > If it isn't much more difficult, I'd like to be able to drive a bar graph of > 12 to 16 LEDs as well. ============================================ try epanorama. This would also be a good project to learn c programming on a microcontroller. Use a text lcd as the bar graph. Or a graphics lcd. Look at the Olimex MT128 at olimex.com
From: pjdd on 29 Oct 2006 10:40 Noozer wrote: > Anyone have a simple digital tachometer schematic handy? > > I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine. > Fed by the TACH output of a six cylinder GMC on distributor coil. > > If it isn't much more difficult, I'd like to be able to drive a bar graph of > 12 to 16 LEDs as well. How about doing it the old-fashioned analog way ? An LM2907/2917 as F-V converter, and a 4 1/2-digit DVM module for readout. Another venerable IC, the LM3914 could provide the bar graph display, two of them for a 20-dot scale.
From: Homer J Simpson on 29 Oct 2006 10:53 "Noozer" <dont.spam(a)me.here> wrote in message news:GmQ0h.206269$5R2.25840(a)pd7urf3no... > Anyone have a simple digital tachometer schematic handy? > > I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine. > Fed by the TACH output of a six cylinder GMC on distributor coil. > > If it isn't much more difficult, I'd like to be able to drive a bar graph > of 12 to 16 LEDs as well. http://www.siliconchip.com.au/cms/A_102835/article.html A Digital Tachometer For Your Car Compact design features a 4-digit LED display and a bargraph. It can also provide gearchange indication and drive a rev limiter.
From: Tam/WB2TT on 29 Oct 2006 22:03
"Noozer" <dont.spam(a)me.here> wrote in message news:GmQ0h.206269$5R2.25840(a)pd7urf3no... > Anyone have a simple digital tachometer schematic handy? > > I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine. > Fed by the TACH output of a six cylinder GMC on distributor coil. > > If it isn't much more difficult, I'd like to be able to drive a bar graph > of 12 to 16 LEDs as well. > Build a frequency counter, and pick the right gate time. I think if you make the gate time 1/300 of a minute, the display will show RPM/100. Make it 1/30th of a minute (2seconds), and it will display RPM/10. There is a common coil? Tam |