anyone know how to build a digital rev counter, the type using 7 bit led number indicators, or where i can find a wiring diagram on this internet
thingy!!
Maplin used to sell a kit might be worth chekcing their web site http://www.maplin.co.uk
However, digital tachometers are awfull, horrible things. You'd be far, far better off with a good quality analog style unit.
hi I am producing theas that use a number of LEDs to signal the RPM if you are intrested then give me an email
However I do have a bit of a back log of devices to build because of problem with parts delivery at the moment
next weak some time I should have a section on the locost coop web sight.
ooh, there's going to be a locost coop website? where?
i know this was talked about a couple-a weeks ago.
any update on this?
where?
Ned.
what so you can supply me with a set of green-orange-red LEDS which will light up as the revs increase like on the F1 Cars?
if you can i would be very interested
Thanks
Yes that is exactly what I can build you however I have a back log of stuff to do for other people first so there would be a bit of a weight involved and I would need to know what engine you have.
I'm making one too - going for row of LEDs, every 400rpm at low revs & every 200rpm over 7000 (yeah bike engine). The easy way to do this is count ignition pulses in a fixed time period, however this gives a lousy jerky response, so I'm measuring the time from one ignition pulse to the next and doing a 1/t thing. The other thing I'll be doing is to make the bar graph the shape of the engine's power curve. Should be fairly cool (I hope). Just using big 7 segment LEDs for mph & the 10 LED bargraphs for fuel oil and temp. ETA about 4 yrs.... (though I have some rtl VHDL already & a xilinx spartan dev kit to try it on)
quote:
Originally posted by Bob C
I'm making one too - going for row of LEDs, every 400rpm at low revs & every 200rpm over 7000 (yeah bike engine). The easy way to do this is count ignition pulses in a fixed time period, however this gives a lousy jerky response, so I'm measuring the time from one ignition pulse to the next and doing a 1/t thing. The other thing I'll be doing is to make the bar graph the shape of the engine's power curve. Should be fairly cool (I hope). Just using big 7 segment LEDs for mph & the 10 LED bargraphs for fuel oil and temp. ETA about 4 yrs.... (though I have some rtl VHDL already & a xilinx spartan dev kit to try it on)
If a few folk were interested I'd do a proper kit, PCB and parts list; trouble is I won't need it for years so god knows when it'll be
ready. It does what I want in a dash, not necesssarily to everyone's taste! I'll post more details when I've more hardware... Non
linear analog tacho the shapoe of the power curve (that'll be the shape of a R1 power curve.....) everything dims in the dark (Headlights on) be
about 3x6inches big. Outputs to drive LCD totalisers for odometer/trip.
cheers
Bob C
quote:
Originally posted by ceebmoj
Yes that is exactly what I can build you however I have a back log of stuff to do for other people first so there would be a bit of a weight involved and I would need to know what engine you have.
many moons ago, I made a digital reve counter. It wasnt very readable. The problem with a rev counter is that the revs change very rapidly, giving a
rapid changing numeric display thats very hard to make sense of!
A trend bar, or limit leds would be much easier for a human to make sense of.
atb
steve
Hi they are going to be some thing like 80 quid when I have finished them has it has taken me much longer than expected to develop them. To build a system that switch on an LED at various RPM is relatively easy. However the rev limiter has become something of a problem I just cant put down. I come up wit a nice solution and the I go to bed and wake up the next day with a better one. Witch is probably starting to annoy thowes who I have said that I am building one for already however the rpm limiting is now nice and progressive and does not lead to the banding that you get in lots of comershal systems.