| 摘要 |
PROBLEM TO BE SOLVED: To provide a vibration isolator capable of obtaining a proper vibration isolation effect for a target to be isolated from vibration at a limited low frequency band by using an inexpensive control means. SOLUTION: When an ignition pulse signal SP and a vehicle speed signal SS are inputted to a sine wave signal generator 11 at the time of idling an engine, these signals converted into a sine wave signal SSI adjusted to a phase and frequency corresponding to vibration and the signal SSI is outputted. Simultaneously a carrier signal SC to be a triangular signal having frequency more than audible signal frequency is generated from a carrier signal generator 12. The sine wave signal SSI and the carrier signal SC are inputted to a comparator 13, an amplitude-modulated pulse signal SH to be turned on when the signal SSI is larger than the signal SC is outputted from the comparator 13 and a switching device 14 is turned on/off, so that a control electric signal is supplied from a battery power supply 15 to a coil in an electromagnet 55 mounted on the engine, an excitation board is vertically excited and a vibration isolating effect can be actively displayed. |
