Abstract: To suppress a fluctuation in resonance frequency caused by an input signal voltage in a tunable circuit, a respective capacitor is connected to each of two variable capacitance diodes connected in series-opposition.

Abstract: A frequency conversion circuit in which effects of odd order terms in the input and output characteristics of the active elements of the circuit, which otherwise would produce IM interference, are eliminated. A superposition signal composed of two signals of different frequencies is applied, in opposite phases, to control inputs of a differential pair of transistors. A common load is coupled to the differential pair with the odd order terms being cancelled at the common connection point of the differential pair. The common load is preferably a resonant circuit.

Abstract: The response time of an ordinary or differential transistor switching circuit controlled by the charging of a capacitor C.sub.1 is shortened by rapidly charging the capacitor through a transistor Q.sub.6 connected in parallel with the charging resistor R.sub.1 of the capacitor. The transistor is rendered conductive before the differential switching region is reached in response to the capacitor charge reaching a predetermined level, whereby the charging curve thereafter follows a steep rise to sharply reduce the switching time.

Abstract: The response time of an ordinary or differential transistor switching circuit controlled by the charging of a capacitor C.sub.1 is shortened by charging the capacitor through a constant current source comprising a transistor Q.sub.6, a resistor R.sub.1 and diodes D.sub.1, D.sub.2, to thereby provide a sharp transfer characteristic. The charging time may be even further shortened by increasing the constant current supply at an intermediate threshold level using a further ordinary or differential transistor switching circuit, thereby providing a break in the response characteristic and increasing its slope after the threshold point.

Abstract: A shearing tool for synthetic resin tubes in which a lower jaw is connected to the leading end of an upper handle portion, a lower handle portion is pivoted at the leading end to the rear and lower end of said lower jaw, an upper jaw or shearing blade having a cutting edge is pivoted in an intermediate position to said upper handle portion above the pivot connection of said lower jaw to said lower handle portion, said lower jaw is provided with an arcuate tube receiving recess in the upper surface thereof, an opening is provided in forward portion of said upper handle portion extending therefrom to the leading end of said lower jaw for receiving said upper jaw, a connection link is connected between the rear end portion of said blade interposed between said upper and lower handle portions and the lower handle portion in a position rearwardly of said pivot connection of the lower jaw to said lower handle portion for urging said cutting edge toward said tube receiving recess when said upper and lower handle por

Abstract: A picture image information band compression and transmission process includes the steps of providing one set of three scanning lines making information of the first scanning line of each one set as an estimation scanning line, estimating a picture element to be estimated by four consecutive picture elements, preparing estimated picture image informations, and translating the estimation reference scanning line and two estimated picture image information into run length codes and into mode codes, respectively, and compressing and transmitting the run length codes.