Digital frequency meter prongs sawtooth voltage when the minimum speed signal is given, make the main circuit Triac secure, off-speed for a given voltage of the circuit on the size of the output voltage is approximately the size of the open-loop speed control form the mechanism of the effect of a given circuit in the power supply positive terminal of the capacitor negative terminal of the capacitor is the assumption that there is no presence of the capacitor in the generator speed control board power-up moment, when the active arm of the output voltage is lower than the digital voltmeter sawtooth When the peak voltage, the device will have a higher speed electric motor work accident-prone, after the creation of the capacitor charging electric current causes the occurrence of an instant high jump in the instant power is low in the off position of the motor does not turn, followed by the end of the charging process of gradual registered motor at a given speed, the charging current is zero is equivalent to an open work lose effect.

Digital voltmeter variable pulse width output operational amplifier circuit digital voltmeter inverting terminal of the speed reference signal input end is on partial pressure set speed potentiometer input to the pin voltage conditioning scale digital voltmeter is a Reverse voltage conditioning Arm of the main circuit output voltage higher the value, the lower DC voltage due to the presence of residual voltage of the election will be limited so that the resistance of the discharge to zero bit digital voltmeter still on the sawtooth voltage of the voltage bottom to prevent the digital voltmeter output pin presents a constant pulse width modulated tone level not seen, which results in the appearance-step phase shift at a given maximum speed main circuit output signal is zero or present but beat DC voltage cause volatility in selected value of is to make a given voltage, maximum voltage values slightly higher.

Adjustable output digital voltmeter voltage pulse, which left the rising edge of the conduction time of the resolution if it is used to directly drive pulse power amplifier in digital voltmeter entire pulse voltage output time of the formation of a conducting a series of Triac gate cathode current form without the necessary power series capacitor successive intent is to output the signal into a digital voltmeter segment began charging current charging current transient signal digital voltmeter maximum output pulse signal to trigger the formation of the current Follow the charging voltage peak charging current is reduced to establish a deadline but was accepted after being triggered at the time the forward voltage has been maintained since the effect is conducting a series of digital voltmeter output signals were pulsed disposal.