driving a rev counter
Discussion
I have a complete conundrum that I need help solving.
I am putting a custom dash into a turbo diesel and will be adding a rev counter. In a petrol car the counter would be hooked up to the coil negative teminal or where applicable the ignition module (ecu)
Anyway my car has neither of these!! The rev counter in question is designed for either a 4 , 6 or 8 cylinder engine and works of a 2,,3 or 4 pulse signal respectively.
I need to know how exactly I can replicate such a signal on the 4 cylinder diesel engine. So far I have been told the alternator can drive it, but then at a later date told the alternator will actually pulse around 12 times per revolution and the revolution is at a 2:1 ratio with the crank so effectively 24 pulses. Needless to say it wont be suitable.
Anyone on here good with electronics know of a solution?
PS its a pug 306 1.9td (not hdi) and didnt have the rv counter as standard as it wasnt always a turbo engine.
I am putting a custom dash into a turbo diesel and will be adding a rev counter. In a petrol car the counter would be hooked up to the coil negative teminal or where applicable the ignition module (ecu)
Anyway my car has neither of these!! The rev counter in question is designed for either a 4 , 6 or 8 cylinder engine and works of a 2,,3 or 4 pulse signal respectively.
I need to know how exactly I can replicate such a signal on the 4 cylinder diesel engine. So far I have been told the alternator can drive it, but then at a later date told the alternator will actually pulse around 12 times per revolution and the revolution is at a 2:1 ratio with the crank so effectively 24 pulses. Needless to say it wont be suitable.
Anyone on here good with electronics know of a solution?
PS its a pug 306 1.9td (not hdi) and didnt have the rv counter as standard as it wasnt always a turbo engine.
I have tried a genuine rev counter and it was no use, I am going for a custom dash so I ge more info on various engine temps, have a more accurate speedo which is electronic drive not cable and the fuel and oil level is more accurate. The normal peugeot ones are very unreliable.
Thanks for the diagram, unfortunatley it makes no sense as the codes used against the diagram mean nothing. Do you hav a link to where that image came from? maybe the site has more detailed info.
Thanks
Thanks for the diagram, unfortunatley it makes no sense as the codes used against the diagram mean nothing. Do you hav a link to where that image came from? maybe the site has more detailed info.
Thanks
r1ch1e said:
Thanks for the diagram, unfortunatley it makes no sense as the codes used against the diagram mean nothing. Do you hav a link to where that image came from? maybe the site has more detailed info.
Thanks
That's exactly what I thought, but hoped it might make more sense to you!
Anyway, FWIW here's the site: www.cowdery.demon.co.uk/
The CD4040 is a 12 stage ripple counter. Essentialy it is used as a binary divider in this circuit. Pin 6 is the Q3 output, and is therefore a divide by 2^3 = 8.
If the XUD alternator pulse really runs at 24x the crank speed, you will need a more sophisticated divider as this isn't a binary divisor. You could use the 4040 in conjunction with a 4017 decade counter to get an arbitrary divisor.
If the XUD alternator pulse really runs at 24x the crank speed, you will need a more sophisticated divider as this isn't a binary divisor. You could use the 4040 in conjunction with a 4017 decade counter to get an arbitrary divisor.
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