I am trying got make an adjustable rpm controller for my Autometer shift light. I have been planning this for awhile and found this on another site a while ago...
"What I did was put a variable potentiometer (10K) in and set it to 3600 ohms (5000 rpm).
From then on, each ohm of resistance = 1 rpm added to 5000 rpm. Units are now interchangeable.
The output from the pot goes to 3 of teh DIP switches. They are 0, 500, and 100, so if one is selected, that output would then be 5000, 5500, or 6000 rpm. That value goes into the other 5 DIP switches which have values of 100, 200, 300, 400, and 500.
The outut is then 5000 rpm (3600 ohms) PLUS 0, 500, or 1000 PLUS 100, 200, 300, 400, or 500. That gives the opportunity for any 100 rpm increment from 5100 (switches 6 and 1) to 6500 rpm (switches 8 and 5).
5100 rpm = 6 and 1 (5000+0+100)
5800 rpm = 7 and 3 (5000+500+300)
6500 rpm = 8 and 5 (5000+1000+500)
To get the resitance values, I used a number of resistors (they add in series and divide in parallel) on a circuit board. I put the whole thing in a small (~1.5"x3") box and cut the switch box out and a hole for the pot. I then spliced into the two wires in teh shift light that go to the place where the pill plugs in."
As well as this diagram to go with the above....
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So today I attempted to make this... and failed.
I followed the above diagram to the T. Testing the circuit and switching rockers on and off shows nothing that make sense... is about the most accurate I can describe. Does anyone know electronics like this and can explain how I am supposed to make this in "dumbed down" english for me?
Basically what I have is a circuit board with an 8 position DIP switch soldered to it.
The "MAIN IN" wire connects to one side of the DIP "IN" Pos. 8 and jumps over to connect 7 as well. On the opposite side of the DIP "OUT" from rocker 7 I have a 500 ohm resistor and from 8 I have a 1000 ohm resistor to the other side of the circuit board. On this side I connect both circuit 7 and 8 again and jump it back down to circuit 1 "IN to the DIP". This wire them jumps from 1-2, 2-3, 3-4 and last 4-5 on the "IN" side of the DIP switch.
Then from each circuit from 1 through 5 on the "OUT" side of the dip switch I have a corresponding resistor for each... 100 ohms for 1, 200 ohms for 2... all the way to 500 ohms on 5. These resistors also run to the other side of the circuit board. At this point I jumped the circuits together.... This wire them jumps from 1-2, 2-3, 3-4 and last 4-5 on the "MAIN OUT" side of the circuit board. At this point one main lead runs off the board as the "MAIN OUT". Using my DVM and set on ohms it works nothing like I had expected. I can test each circuit on the dip 1-8 alone and they work perfectly... circuit 1 adds 100 ohms and so on. But start turning on more than 1 circuit at a time and she goes wacky.
Help??
"What I did was put a variable potentiometer (10K) in and set it to 3600 ohms (5000 rpm).
From then on, each ohm of resistance = 1 rpm added to 5000 rpm. Units are now interchangeable.
The output from the pot goes to 3 of teh DIP switches. They are 0, 500, and 100, so if one is selected, that output would then be 5000, 5500, or 6000 rpm. That value goes into the other 5 DIP switches which have values of 100, 200, 300, 400, and 500.
The outut is then 5000 rpm (3600 ohms) PLUS 0, 500, or 1000 PLUS 100, 200, 300, 400, or 500. That gives the opportunity for any 100 rpm increment from 5100 (switches 6 and 1) to 6500 rpm (switches 8 and 5).
5100 rpm = 6 and 1 (5000+0+100)
5800 rpm = 7 and 3 (5000+500+300)
6500 rpm = 8 and 5 (5000+1000+500)
To get the resitance values, I used a number of resistors (they add in series and divide in parallel) on a circuit board. I put the whole thing in a small (~1.5"x3") box and cut the switch box out and a hole for the pot. I then spliced into the two wires in teh shift light that go to the place where the pill plugs in."
As well as this diagram to go with the above....
So today I attempted to make this... and failed.
I followed the above diagram to the T. Testing the circuit and switching rockers on and off shows nothing that make sense... is about the most accurate I can describe. Does anyone know electronics like this and can explain how I am supposed to make this in "dumbed down" english for me?
Basically what I have is a circuit board with an 8 position DIP switch soldered to it.
The "MAIN IN" wire connects to one side of the DIP "IN" Pos. 8 and jumps over to connect 7 as well. On the opposite side of the DIP "OUT" from rocker 7 I have a 500 ohm resistor and from 8 I have a 1000 ohm resistor to the other side of the circuit board. On this side I connect both circuit 7 and 8 again and jump it back down to circuit 1 "IN to the DIP". This wire them jumps from 1-2, 2-3, 3-4 and last 4-5 on the "IN" side of the DIP switch.
Then from each circuit from 1 through 5 on the "OUT" side of the dip switch I have a corresponding resistor for each... 100 ohms for 1, 200 ohms for 2... all the way to 500 ohms on 5. These resistors also run to the other side of the circuit board. At this point I jumped the circuits together.... This wire them jumps from 1-2, 2-3, 3-4 and last 4-5 on the "MAIN OUT" side of the circuit board. At this point one main lead runs off the board as the "MAIN OUT". Using my DVM and set on ohms it works nothing like I had expected. I can test each circuit on the dip 1-8 alone and they work perfectly... circuit 1 adds 100 ohms and so on. But start turning on more than 1 circuit at a time and she goes wacky.
Help??
