David Bartlett
New Member
Hi all,
You have a great forum going here and I'm hoping you can help me out.
I'm looking to build a simple shift light for my car, so at 5400rpm the light comes on.
I'm hoping to use National Semiconductors LM2907 (more info on the chip here - **broken link removed** )
My car outputs 270hz = 5400rpm, power souce is auto 12v(but not a steady 12v remember)
Here's the plans from National:
**broken link removed**
As a begginner, I could easily build the board but I can't for the life of me figure out which capacitors/resistors to use. Would it be possible to use a varaiable resister as R1 so I could adjust the shift point? I plan on using a standard 3.5v Blue LED, so I imagine a resistor will be needed to drop voltage. Maybe some of you guys could look over and provide me with a list of parts, suggestions or any direction.
Thanks,
Dave
You have a great forum going here and I'm hoping you can help me out.
I'm looking to build a simple shift light for my car, so at 5400rpm the light comes on.
I'm hoping to use National Semiconductors LM2907 (more info on the chip here - **broken link removed** )
My car outputs 270hz = 5400rpm, power souce is auto 12v(but not a steady 12v remember)
Here's the plans from National:
**broken link removed**
As a begginner, I could easily build the board but I can't for the life of me figure out which capacitors/resistors to use. Would it be possible to use a varaiable resister as R1 so I could adjust the shift point? I plan on using a standard 3.5v Blue LED, so I imagine a resistor will be needed to drop voltage. Maybe some of you guys could look over and provide me with a list of parts, suggestions or any direction.
Thanks,
Dave