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EP0109081A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Bidirectional constant current driving circuit

Assignee: NEC Corp
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Filing: 1983-11-14
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Granted: —
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Expires: 2003-11-14
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Abstract

Abstract The bidirectional constant current driving circuit has an input terminal (1), an output terminal (2) and first and second power supply terminals (Vp, V N ), for driving a load (3) coupled to the output terminal in response to an input signal (V A ) applied to the input terminal (1). The driving circuit comprises a first transistor (12) having a first electrode connected to the first power supply terminal (Vp); a second transistor (11) having a first electrode connected to the first power supply terminal (Vp), and second and third electrodes connected to a second electrode of the first transistor (11); a third transistor (14) having a first electrode connected to the second power supply terminal (V N ); a fourth transistor (13) having a first electrode connected to the second power supply terminal (V N ), and second and third electrodes connected to a second electrode of the third transistor (14). A first and a second resistor (15, 16) are serially connected between the third electrode of the second transistor (11) and that of the fourth transistor (13), the junction of the first and second resistors (15, 16) being connected to the input terminal (1). A coupling means couples the third electrodes of the first and third transistor (12, 14) to the output terminal (2), respectively. This circuit gives constant currents in both positive and negative directions (Fig. 1).

Inventors

  • 👤 Akira Fujii

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 07:27
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3066

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 225 words
A bidirectional constant current driving circuit having an input terminal (1), an output terminal (2) and first and second power supply terminals (V P ,V N ), for driving a load (3) coupled to said output terminal in response to an input signal (V A ) applied to said input terminal (1), comprising: a) first transistor means (12) having a first electrode connected to said first power supply terminal (V P); b) second transistor means (11) having a first electrode connected to said first power supply terminal (Vp), and second and third electrodes connected to a second electrode of said first transistor means (11); c) third transistor means (14) having a first electrode connected to said second power supply terminal (V N ); d) fourth transistor means (13) having a first electrode connected to said second power supply terminal (V N ), and second and third electrodes connected to a second electrode of said third transistor means (14); e) first and second resistor means (15,16) serially connected between the third electrode of said second transistor means (11) and that of said fourth transistor means (13), the junction of said first and second resistor means (15,16) being connected to said input terminal (1); and f) coupling means for coupling the third electrodes of said first and third transistor means (12,14) to said output terminal (2), respectively.
Claim 2
Dependent Claim 225 words
A bidirectional constant current driving circuit having an input terminal (1), an output terminal (2) and first and second power supply terminals (V P ,V N ), for driving a load (3) coupled to said output terminal in response to an input signal (V A ) applied to said input terminal (1), comprising: a) first transistor means (12) having a first electrode connected to said first power supply terminal (V P); b) second transistor means (11) having a first electrode connected to said first power supply terminal (Vp), and second and third electrodes connected to a second electrode of said first transistor means (11); c) third transistor means (14) having a first electrode connected to said second power supply terminal (V N ); d) fourth transistor means (13) having a first electrode connected to said second power supply terminal (V N ), and second and third electrodes connected to a second electrode of said third transistor means (14); e) first and second resistor means (15,16) serially connected between the third electrode of said second transistor means (11) and that of said fourth transistor means (13), the junction of said first and second resistor means (15,16) being connected to said input terminal (1); and f) coupling means for coupling the third electrodes of said first and third transistor means (12,14) to said output terminal (2), respectively.
Claim 3
Dependent Claim 44 words
A bidirectional constant current driving circuit as claimed in Claim 1, wherein each of said first and second transistor means (12,11) has an inverse conductive junction structure with respect to the conductive junction structure of each of said third and fourth transistor means (14,13).
Claim 4
Dependent Claim 41 words
A bidirectional constant current driving circuit as claimed in Claim 1 or 2, wherein each of said first and second transistor means (12,11) comprises a PNP transistor, and each of said third and fourth transistor means (14,13) comprises an NPN transistor.
Claim 5
Dependent Claim 41 words
A directional constant current driving circuit as claimed in any one of Claims 1 to 3, wherein said coupling means includes a Zener diode (17) provided between said output terminal (2) and the third electrode of said third transistor means (14).
Claim 6
Dependent Claim 29 words
A directional constant current driving circuit as claimed in any of one Claims 1 to 4, wherein said first, second, third electrodes are emitter, base and collector electrodes, respectively.

References Cited (Backward Citations)

DE2452445A1 Cited
DE2600594B2 Cited
US4267521A Cited
US4140977A Cited

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