A torsion pcndulum of long period is made and shown in Figs l, 2 and Photos 1, 2. A rotor rotates around a verticalaxis, and the case of the rotor is filled with oil. Therefore the weight of the rotor is supported by the buoyancy of the oil, and the load of pivot bearings becomes very small. Total size of the pendulum is 88φ×69mm, and the calculated period is 42 seconds. It's Characteristics is shown in Figs 5 and 6.
This paper has the two objects. One is to analyze the transistor - oscirlation circuit which drives the magnetic escapement. The other is to give the magnetic reactive force of the timekeeping oscillator the general expressions and to treat it quantitatively. Since the transitor - oscillation circuit driving the magnetic escapement has large - signal behavior, the equivalent circuit with so called h - parameters which is used in small signal behavior is not available. There is a few example in which the transistor with largesignal behavior has been analyzed, (1)(2)(3)but it can not be used to investigate the mechanics of the oscillation circuit with the saturation of the transistor. In recent year LC - oscillation circuit with large - signal behavior has been analyzed by the method in which the characteristic curve of I_E -V_BE is approximated with broken (4) line. But it has not been discassed on the saturation of the transistor. Our method is not only the basis of the approximation with broken line above described, but on the basis of the fact that the circuit includes the working of motor and generator in electro - dynamical driving and the saturation of the transistor. As the results, values computed from this are found to be good agreement with values measured. Furthermore it is presented that the magnetic reactive force of the timekeeping oscillator can be derived to the general expressions from that of the static torque of the magnetic escopement.