STVA Secondary Throttle Valve Adjustment
In shop ordercomment add "Please instead of internal DBW, add additional 2A 4-wire bipolar stepper driver controlled from some ECU PWM output". (same price as internal DBW bridge, select that for price).
Suzuki GS-F 650/1250 (ccm3)
Secondary Throttle Valve
- 2A 7 Ohm bipolar 4 wire stepper for intake pipe cross-section area control
- 256 steps enough?
- or more steps needed? Please check if available
- step down to 0 (actually fully up?) at powerup/ Ignition ON->full open-> set 15% position before/during start (as set for 0 RPM)
- step to command position after that (PWM input or digital input)
Current and Power... Each coil is 2A * 13V = 26W... The stepper total dissipation is 2 x 26W > 50W stepper that must NOT be powered continuously... IT WOULD OVERHEAT
- stepper must be powered DOWN when it reaches target, or better: lower (appr. 0.5A 7W/coil) holding current should be applied...
Analog input 0.5V .. 4.5V (supplied from 5V)
- 0.5V .. 4.5V
- mcp3208 analog input for logging.