CODE SIGNAL INPUT APPARATUS

• US 3,626,406 A
• Filed: 08/26/1970
• Issued: 12/07/1971
• Est. Priority Date: 09/26/1969
• Status: Expired due to Term

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Tadamitsu Iritani
• Inventors: Iritani, Tadamitsu
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/067,031
• Time in Patent Office: 468 Days
• Field of Search: 307/242,246,259 178/66,68 340/347DD,350,354,345,167,365,174LA,173R
• US Class Current: 340/327
• CPC Class Codes: H01H 9/167 Circuits for remote indication
• CPC Class Codes: H03M 11/22 Static coding H03M11/26 takes precedence

Abstract

In apparatus to write a code signal generated by code signalgenerating means such as a switch located at a measuring point into a computer, an insulation transformer is connected between the code signal-generating means and an output circuit. A series diode and a parallel capacitor are connected to a circuit interconnecting the primary winding of the insulation transformer and the code signal-generating means. A pulse is normally applied to the secondary winding of the insulation transformer to charge the capacitor through the diode. The capacitor is discharged when the switch is closed to decrease the secondary impedance of the transformer to produce an output signal corresponding to the code signal.

Claims

1. Code signal input apparatus comprising code signal-generating means, an insulation transformer connected between said code signal-generating means and a computor, a diode connected in the circuit interconnecting the primary winding of said insulation transformer, and said code signal-generating means, and a capacitor connected across said primary winding to store the condition of said code signal, the polarity of said diode being selected such that said diode responds to the voltage across said capacitor to write said code signal into said computer.

2. Code signal input apparatus comprising a plurality of code signal-generating switches which generate code signals by the opened and closed conditions of their contacts, transmission lines each including a diode and a capacitor, insulation transformers respectively connecting said switches to data processing means of a computer through said transmission lines, means to normally supply a pulse signal to the secondary windings of said insulation transformers to charge said capacitors through said diodes to cause said capacitors to act as bias sources for said diodes whereby to vary the impedances of the secondary windings of said insulation transformers in response to the closed and opened conditions of said switches to read said code signals generated by the opening and closing of said switches.

3. The code signal input apparatus according to claim 2 which further comprises an inverter to invert said pulse signal so as to apply the inverted signal to one terminal of said secondary windings of said insulation transformers respectively through resistors, means to apply a DC voltage to the other terminals of said secondary windings and AND-gate circuits, one input of said AND-gate circuits being connected to said one terminal of said secondary windings and the other input of said gate circuits being connected to receive said pulse signals.