How to determine the speed
You will need
- electromechanical tachometer, electronic car tachometer, analogue mechanical clock tachometer.
To control the crankshaft speed in an internal combustion engine using an electromechanical tachometer, connect its sensor to the crankshaft ratchet mechanism and connect a 12 volt power supply to the tachometer. Start the car engine. Changing the frequency of rotation of the crankshaft to achieve the desired modes, read its value from the sensor of the electromechanical tachometer. When using this method, the approximate frequency of the crankshaft is determined, since the error introduced by the imperfect construction of this tachometer is high.
For a more accurate determination of the crankshaft speed, connect the signal input of the electronic car tachometer to the output of the ignition coil connected to the circuit breaker of the car ignition distributor.Connect the power of 12 volts to the electronic car tachometer. Start the car engine. Changing the frequency of rotation of the crankshaft within the required limits, read his testimony from the display of the electronic tachometer. This method has high accuracy.
To determine the frequency of rotation of the motor shaft, read this value on a plate placed on the motor housing. If the plate is missing or the inscription in it is erased, turn on the electric motor. Lift the shaft to the axis and touch it with a watch mechanical tachometer sensor. Without removing the sensor from the axis of the motor shaft, press the "Start" button on the tachometer housing. After stopping the movement of the arrow, read the readings of the frequency of rotation of the motor shaft opposite it. Then press the “Reset” button to return the tachometer to its previous state. If necessary, repeat the measurement.