######  
    ##   
   ##    
  ##     
 ######  
         

         
         
 #####   
 ##  ##  
 ##  ##  
 ##  ##  
 ##  ##  
         

    ##   
         
   ###   
    ##   
    ##   
    ##   
 ## ##   
  ###    

         
         
 #    #  
 #    #  
 #    #  
  #  #   
   ##    
         

         
         
  ####   
 #    #  
 ######  
 #       
  ####   
         

IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now.


Visit Preferences to set your user name
Summary of change:
'''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? No, appr. 1200 steps ** or more steps needed? Please check if available. We'll see * 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... ** Appr 30..50% current should prevent premature damage to throttle stepper motor '''Analog input 0.5V .. 4.5V (supplied from 5V)''' * '''0.5V .. 4.5V''' * '''EC18/pin1 mcp3208ch0 analog input''' for logging and actual '''"TPS2" feedback'''. ---- '''6+2 IGBT''' * 2 ignition recommended: EC36/34,36 (ch2,3) Wasted spark. * power ign outputs: 4 free remaining * logiclevel ign output controls "Boost PWM" => STVA throttle-stepper position (available on EC36/pin... while also commanding the throttle controller) * 1 logiclevel ign => stepper wire (2A) original trace cut * 3 p259 EC36pins => stepper wires (2A) original trace cut ** colors: GW, ** colors: PY * EC18/pin1 mcp3208ch0 throttle feedback (TPS2). Can also be logged by v3 main processor ---- 2nd RS232 not needed, (1 RS232 on EC18/14-15... standard) ---- '''Secondary PWM aka. Boost alternate''' * i259/ch5 (EC31/12) PWM (filtered with 30k and 10uF) command ** Appr 100..125 Hz recommended (max is 375 Hz for secondary PWM). ** IMPORTANT: 25..33 Hz is not enough, the throttle would move slightly causing continuous wear (and prevent standby current, so could even overheat driver and motor in the long run). 40 Hz was enough during experiments, but best to apply greater frequency. Always '''test with lower PWM frequency, and check that stepper motor does not get hot in 5 minutes. Than set 10..20% greater PWM frequency, and test again for min 10 minutes'''. Stepper motor gets warm, but should not get hot. Appr. 500..1200 Hz sound might be heard from the motor when stepper is at holding current, that is normal (that means reduced current is flowing when not stepping which prevents overheating when position is hold stable) ** 0..80% in Secondary PWM / Boost alternate table (RPM dependent, but possibly RPM and MAP dependent). Greater than 80% PWM duty is not recommended, and opening the throttle more than 90 degrees makes no sense anyway.
Optional: Add document to category:
Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.