A very nice project for everyone who is interested in car Tuning.
It is based in the VCRGB Software shown here.
The circuit measures the engine RPM (or Speed) and changes the color of an Instrument illumination (or whole
Dashboard), dependent of the RPM
The senitivity / RPM Levels can be adjusted
Idle Blau
Normal:Green
High RPM :Red
The use of modern ultrabright LED's allowth this circuit to be operaten in many applications.
R1 470 Ohm
R2 22kOhm
R3 10kOhm
C1 22nF
R6 100k
C4 1uF
D1 1N4148
R9 15k
R7 100k
R8 15k
R5 15k
C3 4.7 uF
C5 4.7uF/35V
IC3 LM78L05
C6 100nF Keramik
R10 100k
C7 100nF
R14 4.7k
R11, 12,13 150-270 Ohm, je nach LED's
D2 7.5V Siehe Text
The Operating Voltage is connected to Pad1/2 and powers a LM2907/2917 Frequency/Voltage-Converter.
The RPM Signal (connected to Breaker or Tacho Signal Generator) is connected to PAD3.
The LM2907 converts the Frequency (proportional to engine RPM) to a corresponding Voltage, which is used by the Atmel Tiny15 to control the LED's.
With R6 you can adjust Sensitivity, with R7 you can adjust for idle RPM.
The Microcontroller has a 5V Regulator for proper operation.
The LM2917 has a builtin Z-Diode. When using a LM2907, you must use a Z-Diode D2 of about 7.5V to stabilize the Supply Voltage of IC1.
The Controller has to be programmed with this Software
