Abstract: A jack having switch is constituted so that a movable armature is displaced so as to be separated from a fixed armature which contacts with the movable armature by insertion of a plug, the plug and the movable armature are brought into a contact state, and this state is maintained. The movable armature has two-pronged branch portions along a plug insertion/uninsertion direction, and the branch portions have plug contact portions which are expanded to be displaced outward by the plug to be inserted therebetween and hold the outside of the plug so as to be connected to the plug. The branch portions have fixed armature contact portions which contact with the movable armature arranged to be opposed to the branch portions when the plug is not inserted.

Abstract: There is provided a compact, low-cost decorative light blinking device which is capable of accurately and precisely blinking illuminants of channels in response to music (the frequency of sound), and which has circuitry with reduced number of components. An audio frequency range (from 20 Hz to 20 KHz) can be divided into about 10 frequencies.

Abstract: A trigger circuit unit including: a forward circuit block having a pickup circuit such as a microphone for picking up a signal of music so as to convert it into an electric signal; a filter circuit for selecting a portion of the band from a picked up audible frequency band; and a limit amplifier circuit mainly composed of an inverter operation logic IC for amplifying the selected electric signal having a portion of the band and transmitting an output having a predetermined amplitude; and a waveform conversion circuit block having a time constant circuit connected to the output of the forward circuit block and composed of a capacitor having one or more diodes connected in series and a resistor in order to prevent a backflow and to obtain a forward directional voltage difference, wherein analog pulse signals transmitted from the time constant circuit are caused to perform a Schmidt operation having a previously adjusted degree of hysteresis, wherein the rectangular pulse signals transmitted from the waveform co

Abstract: Disclosed is a method of detecting a variation in stray capacitance by use of a PLL circuit.