Solenoids are controlled two ways: pulse width or duty cycle. Pulse width control is used when the frequency is not consistent. An example of pulse width is a fuel injector which is turned on for a determined length of time and then shut off. Duty cycle control is used when the frequency does remain constant. A duty cycle solenoid in ABS is designed to be on and off for a specific time according to a selected ratio-on for 20% of the time and off the other 80%.
Like stepper motors, solenoids are digital actuators. One terminal is attached to battery voltage while the other is attached to the computer which opens and closes the ground circuit as needed. When energized, the solenoid may extend a plunger or armature to control functions such as vacuum flow to various emission-related systems or fuel injection. Most actuators are solenoids.
Idle speed control valves can be constructed with a solenoid instead of a stepper motor. In this case, the function is the same: the ECU sends a signal to the ISCV to control the intake air.
Solenoid valves are also used in ECT transmissions. Shifting is controlled by the solenoid as it opens or closes a hydraulic passage to control oil flow to the shift valves.
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You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.