Abstract: The drop-by-drop evaporation of a liquid or solution is controlled by monitoring the disappearance of each successive droplet and by actuating the deposition of the next droplet until the desired volume is deposited. In the case of a solution, non-volatile residue (NVR) is collected on a deposition surface plate as a relatively small mound. One of a variety of methods may be employed to measure the evaporative behavior of each droplet and to key the deposition procedure. The process is preferably carried out employing a clean deposition surface plate that is maintained at or below the boiling point of the particular liquid or solvent being deposited. The environment is preferably controlled so that inadvertent contamination is precluded from interfering, and thus the method permits the automatic, micro-processor controlled evaporation of liquids with the resultant deposition of non-volatile residues from solutions within relatively short periods of time.

Abstract: A telephone having a non-volatile circuit for automatically dialing 911 upon depression of a single key includes an oscillator activated in response to depression of the key for transmitting clock pulses to a counter. Certain of the output signals from the counter are applied to switches in sequence. The switches are connected to selective column and row leads of the telephone dialer circuit corresponding to the digits in the telephone number to be dialed. The switches short together the respective column and row leads so that the dialer reacts in the same manner it would when the keys of those digits are depressed on the telephone keypad. An output pulse from the counter resets the circuit after the switch connects together the column and row leads of the last digit of the telephone number.

Abstract: An apparatus 10 is employed for interfacing a telephone handset 18 to a telephone network. Typically, a telephone handset has one of a variety of different microphones disposed therein, such as carbon, electret, etc., where each type of microphone has a different output level and impedance. Conversely, the telephone network with which the microphone is to be interfaced has a preselected input impedance and signal requirement intended to match only one type of microphone. The apparatus 10 includes a plurality of switches 82, 84, 86, 88 and resistors 90, 92, 94 that are manually switchable into the circuit either separately or in combination to match the output impedance and signal level of the microphone with the input impedance and signal level of the telephone network. Alternatively, in a second embodiment of the instant apparatus, a variable resistor is employed to match the output impedance and signal level of the microphone with the input impedance and signal level of the telephone network.

Abstract: A transistor 12 is provided for interfacing an electret microphone 16 to a carbon compatible telephone network by impedance matching. The transmitter 12 includes a rectifier 14 constructed from a plurality of Schottky diodes 44, 46, 48, 50 to reduce voltage drop therein and to provide a stable DC voltage supply to the transmitter 12. An amplifier 18 receives an audio signal from the electret microphone 16, amplifies it, and delivers this amplified signal onto the carbon compatible network via the rectifier 14. The amplifier 18 accomplishes this impedance matching while minimizing voltage drop therein. The amplifier 18 includes a first bipolar transistor 68 having its base connected to the microphone 16 and its emitter connected to the negative terminal of the rectifier 14. A second bipolar transistor 70 is connected as an emitter follower.

Abstract: An instantaneous fluid heater having a fluid heating chamber including therein a plurality of electrical heating elements. The supply of electrical power to the respective ones of the electrical heating elements is controlled by a solid state switch which is gated by a zero crossing trigger device to supply power to the heating elements. Each of the trigger devices includes means for comparing a control potential and ramp signal potential coupled to them to selectively gate the solid state switches to energize the heatiing elements in response to the comparison of the potentials. In this fashion, all of the heating elements are not turned on at the same time, and undesirable light flickering and unacceptable disturbances in the line voltage is eliminated.

Abstract: An in-line amplifier is readily connectable to a standard telephone so as to allow for user adjustment of the volume presented to the receiver portion 15 of the handset 14. The in-line amplifier draws electrical power from a replaceable battery 18 so as to be easily attached to the telephone base unit 12. The in-line amplifier includes a voltage level detector 20, which operates to determine when the battery voltage level has fallen below the minimum operating voltage of the in-line amplifier. Ordinarily, the audio signal is passed from the telephone base unit 12 through a controllable amplifier 16 to the receiver portion 15 of the handset 14. However, when the voltage level detector 20 determines that the battery voltage level has fallen below the minimum operating voltage level, a signal is delivered to a low voltage bypass 17, providing a direct electrical path around the controllable amplifier 16 so as to couple the audio signal directly from the base unit 12 to the receiver 15.

Abstract: A displacement sensing and guide apparatus for continuous sheet material wherein the edges of a moving sheet of material are sensed by electromechanical or other variable voltage or variable impedance sensing and feedback means and communicate electrically with an electrical switching system, either directly or through a balanced bridge circuit, to operate the switching system and to indicate and to correct a displacement of the sheet material from a predetermined position.