The Pitch:
I've designed and built a plate-based solid-state PCA (printed circuit assembly) that adds safety and automation capability for the simple 50-150 NOS-shot plate-based carburated systems. We've just completed all the bench-top testing and will be doing physical testing over the next several weeks. The testing is not for the car, it's for the control. NOS and our pony are fairly old friends.
In a nut-shell the circuit provides inputs for: WOT, Oil &/or fuel pressure switch(s), two 5V (logical high active) inputs to automate energizing the system and three (logical low active) inputs to ARM and automate energizing the the system. Outputs are full power, no relays necessary** as follows;
Bottle Blanket............Max current 22amps@12V, expected 15
Bottle Valve...............Max current 22amps@12V, expected 10
NOS Purge.................Max current 22amps@12V, expected 10
NOS Solenoid.............Max current 22amps@12V, expected 10,
Fuel Solenoid.............Max current 11amps@12V, expected 4
NOTE1: Max expected total load: Blanket+Valve+NOS&Fuel Solenoids = 39amps.
NOTE2: Circuit protection is to the board, not individual loads = reduced fuses.
** Relays are recommended to isolate the board from supply voltages on the car as as provide the ability to turn on/off the system regardless of the engine running or not for test purposes. All loads are supported with @ a minimum, most cases are 100% derated, greater than a 25% margin in current.
Also provided are LED indicator outputs for each as well as applied power.
These LED outputs have series resistors on the PCA to allow one-wire and standard (cheap) LED usage. However, those resistors can be shorted on the board to provide a 12V output. This allows additional functionality (actions) the user wants based on the state of the NOS system, e.g. Armed but not active, initiate the LEDs for a lit NOS purge, etc.
I have complete PCB Docs and schematics of the circuit as well as our test vectors, results, and a product description (under construction). On the initial board build we built 4 PCBs and have used (2). I'll sell the PCBs, schematic, part list (vendor, part-number and where to buy), hints, etc. for $50 (The PCB cost alone was $284 for four boards.)
For you techies it's two sided, full solder-mask, plated through holes, silk screen, 2oz. Cu
I'd like to recoup some cost but I'd also like some feedback from other users to improve the capability as well as cost reduce the design and move closer to a mass produced product. A completed, stuffed, and tested board will cost an additional $60. For a total of $110. (I do not stuff the boards, I outsource it) If you can solder through hole....it's easy to do and a significant amount of the parts can be purchased @ Radio Shack. There several FETs on the board that I recommend using only the Fairchild parts as we have characterized them for the manufacturing and part deviations over time as well as providing significant power margin.
Feedback and questions welcome.
I've designed and built a plate-based solid-state PCA (printed circuit assembly) that adds safety and automation capability for the simple 50-150 NOS-shot plate-based carburated systems. We've just completed all the bench-top testing and will be doing physical testing over the next several weeks. The testing is not for the car, it's for the control. NOS and our pony are fairly old friends.
In a nut-shell the circuit provides inputs for: WOT, Oil &/or fuel pressure switch(s), two 5V (logical high active) inputs to automate energizing the system and three (logical low active) inputs to ARM and automate energizing the the system. Outputs are full power, no relays necessary** as follows;
Bottle Blanket............Max current 22amps@12V, expected 15
Bottle Valve...............Max current 22amps@12V, expected 10
NOS Purge.................Max current 22amps@12V, expected 10
NOS Solenoid.............Max current 22amps@12V, expected 10,
Fuel Solenoid.............Max current 11amps@12V, expected 4
NOTE1: Max expected total load: Blanket+Valve+NOS&Fuel Solenoids = 39amps.
NOTE2: Circuit protection is to the board, not individual loads = reduced fuses.
** Relays are recommended to isolate the board from supply voltages on the car as as provide the ability to turn on/off the system regardless of the engine running or not for test purposes. All loads are supported with @ a minimum, most cases are 100% derated, greater than a 25% margin in current.
Also provided are LED indicator outputs for each as well as applied power.
These LED outputs have series resistors on the PCA to allow one-wire and standard (cheap) LED usage. However, those resistors can be shorted on the board to provide a 12V output. This allows additional functionality (actions) the user wants based on the state of the NOS system, e.g. Armed but not active, initiate the LEDs for a lit NOS purge, etc.
I have complete PCB Docs and schematics of the circuit as well as our test vectors, results, and a product description (under construction). On the initial board build we built 4 PCBs and have used (2). I'll sell the PCBs, schematic, part list (vendor, part-number and where to buy), hints, etc. for $50 (The PCB cost alone was $284 for four boards.)
For you techies it's two sided, full solder-mask, plated through holes, silk screen, 2oz. Cu
I'd like to recoup some cost but I'd also like some feedback from other users to improve the capability as well as cost reduce the design and move closer to a mass produced product. A completed, stuffed, and tested board will cost an additional $60. For a total of $110. (I do not stuff the boards, I outsource it) If you can solder through hole....it's easy to do and a significant amount of the parts can be purchased @ Radio Shack. There several FETs on the board that I recommend using only the Fairchild parts as we have characterized them for the manufacturing and part deviations over time as well as providing significant power margin.
Feedback and questions welcome.