Electronic Motocycle Ignition | Electronic Project Circuits

Posts Tagged ‘electronic motocycle ignition’

Injector Pulse Width Monitor with LM324 ,LM3914

The schematic for the pulse width monitor. The heart of the circuit is the transistor current source which charges cap C10 to form an integrator. The theory is that the cap is charged and the voltage across it increases linearly for the amount of time that the injector is energized. As the injector is switched off the voltage in C10 is stored in cap C9 and then C10 is reset to 0 volts to get ready for the next cycle. The output of the circuit is the voltage across cap C9, this voltage is fed directly into U3 the bar graph chip to be displayed as a value between 1-10 on the LEDs. Potentiometer R31 sets the charge rate on C10 and basically sets the max injector on time that can be displayed.

The calibration on this circuit is pretty tricky. You’ll need an oscilloscope and a waveform generator. Setup a 62Hz 0-12v 50% duty cycle square wave at the input to the circuit. Use the scope to monitor the voltage across C10 Adjust pot R31 such that the ramping voltage across C10 just reaches the peak (starts to flatten out). Now adjust the pot R22 in the display circuit such that LED 10 just comes on.

With the calibration described above LED 1 corresponds to about 1.5ms and LED 10 corresponds to about 8ms of injector pulse width (on time). Injector duty cycle in dependent on engine speed according to the following relationship:
% duty cycle = ( pulse width / period )*100
period = 1/[engine speed (rpm) / 60]

Source: http://www.ggimages.com/rx7/pwm.html

Be the first to comment - What do you think? Posted by admin - September 19, 2007 at 10:37 pm

Categories: Automotive, Meter Tags: electronic motocycle ignition, LM324 detector circuit, LM3914, Pulse width monitor

Electronic Motocycle ignition CDI Honda C-90

This Circuit is for 4 cylinder motor, Electronic Motocycle ignition for CDI Honda C-90.
Use small circuit but good work. SCR 1 TIC106 Switching Component for drive ignition Coil to Sparkplug. Detail to see circuit.

Be the first to comment - What do you think? Posted by admin - September 11, 2007 at 10:26 pm

Categories: Automotive Tags: Automotive, electronic motocycle ignition

Electronic car ignition

This scheme is for 4 cylinder motor. This will make your car spent less fuel, be a little bit faster and you won?t have to frequently open your distributor cap to change the contact buttons thus wasting less money.

T1/T2 create one monostable multivibrator in which C2 and R5 determine the length of impulse which is 1,5 msec. Next in line are T3 and then T4 which is Darlington transistor specially developed for electronic ignition which is used as a switch to turn on/off primary coil. Impulses from switch P turn on monostable multivibrator T1/T2. You need to un-connect capacitor that is in distributor cap because it is not needed anymore. While switch P is closed T1 is in off state but T2 is in on state, also T3 and T4 which enables current to flow trough primary coil. When switch P is opened, T1 gets in on state for a moment causing C2 to charge over R6 which makes T2 go to off state because of voltage drop on R6. When T2 is off also T3 and T4 are off and current that was flowing trough primary coil is stopped. Because T2 is in off state, voltage on R8 is increased which is passed trough R5 on T1 base which is still in on state and C2 is still charging. After 1,5 msec. C2 value reaches the level where T2 goes to on state again and T1 goes to off state. Now T2, T3 and T4 are in on state, again, and current flows trough primary coil again. R2 and D1 are used to neutralize the effect of impulses caused from ?jumping? of switch P which could turn on monostable multivibrator when it shouldn’t.

Zener diodes Z5 and Z6 are together with R10 limit overcharged voltage impulses that are caused by self induction of primary coil which could damage T4. They should be connected as close as possible to T4.
D7 protects device from wrong polarity.

Coil should have ratio of 1:80 or 1:100 with external resistor Rv which is used for better cooling. Total resisting value (Rp) of primary coil and Rv resistor shouldn’t be under 1,6 ohm’s so current trough T4 wouldn?t be bigger than 10A.
Depending on Rp, R9 have different values:

120?/2W for Rp tot > 2,2?
100?/2W for 1,8? <>Parts:
D1-D4 = 1N4148
D5-D6 = BZX85C ? 180 (replicable with all equivalent types with power of 1,3W)
D7 = 1N4001
R1 = 470 – 1W
R2 = 22k
R3 = 2,2k
R4 = 1k
R5 = 4,7k
R6 = 39k
R7 ? R10 = 100
R8 = 680
C1 ? C2 = 47nF (ceramic)
C3 = 0,22uF 400V (ceramic)
C4 = 100uF (electrolytic)
T1 ? T2 = BC327 (BC327-25, BC327-40)
T3 = BC237B (BC547B, BC547C)
T4 = BUX37 (BU323, BU920, BU921, BU922, BUV37B (u TOP3), BUW29, BUW81, MJ10012, MJ10013, MJ10014, TIP662, TIP665, 2SD683)
Copy from : http://www.electronics-lab.com
Thank you.