Abstract: A musical door chime which includes a repertoire of musical tunes one of which is played when a door pushbutton, preferably the front door pushbutton, is actuated. The musical tune which is played may be selected by means of a keyboard connected to a microprocessor. Digitally encoded representations of the notes of each musical tune are stored in a memory.

Abstract: A musical door chime which includes a repertoire of musical tunes one of which is played when a door pushbutton, preferably the front door pushbutton, is actuated. The musical tune which is played may be selected by means of a keyboard connected to a microprocessor. Digitally encoded representations of the notes of each musical tune are stored in a memory. Each digitally encoded musical note is read from memory by the microprocessor and converted by the microprocessor into a squarewave having the frequency and the duration of the note. The microprocessor is connected to a note strike and decay circuit which is preferably connected in series with an active audio filter circuit for translating the squarewave into a sinusoidal output for energizing a loudspeaker so that relatively high quality audible tones are heard when the musical tune is played.

Abstract: A system is disclosed for controlling a motor which drives an operating mechanism for moving a door, such as an overhead garage door, in either direction between a closed position and an open position in response to actuation of a start switch. The control system includes an encoder including a rotatable disc driven by the motor and control circuitry including an encoder pulse verification circuit associated with the encoder for detecting the direction of door movement as well as increments of travel by the door when the door is moved by the motor under control of a motor command circuit in response to actuation of the start switch. The start switch and a start circuit cooperate with the motor command circuit for energizing the motor to move the door in one direction, for de-energizing the motor to stop the door at any position, and for re-energizing the motor to reverse the door in response to repeated actuation of the start switch.

Abstract: A musical door chime which includes a repertoire of musical tunes one of which is played when a door pushbutton, preferably the front door pushbutton, is actuated. The musical tune which is played may be selected by means of a keyboard connected to a microprocessor. Digitally encoded representations of the notes of each musical tune are stored in a memory. Each digitally encoded musical note is read from memory by the microprocessor and converted by the microprocessor into a squarewave having the frequency and the duration of the note. The microprocessor is connected to a note strike and decay circuit which is preferably connected in series with an active audio filter circuit for translating the squarewave into a sinusoidal output for energizing a loudspeaker so that relatively high quality audible tones are heard when the musical tune is played.

Abstract: A device for measuring the sensitivity of a patient to externally applied vibration. The device includes a pallometer head which supports a vibratable probe. The probe is caused to vibrate with a selected amplitude and at a selected frequency. The head is supported beneath a table with the probe extending through an opening in the table so that the probe can be engaged by a member of the patient as the member rests on the table. The head is supported on a beam which carries a counterweight so that the probe engages a member of the patient with a controlled pressure.