Constant current-source with high voltage protection, compliance circuit
US4091432A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1976 |
| Grant date | May 23, 1978 |
| Priority date | — |
| Expiry date | Oct 1, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/461
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A closed loop operational amplifier circuit for providing a constant current in the closed loop for generating a precision constant current through an unknown resistance for measuring the resultant voltage drop across the resistance. The closed loop circuit having a compliance circuit with a high voltage diode for preventing damage to a transistor in the compliance circuit in one polarity direction and a current limiting circuit including the transistor for preventing damage to the transistor from high voltage in the opposite polarity direction, and a voltage comparison circuit responsive to a high voltage in the opposite direction for reverse biasing the high voltage transistor to prevent it from entering the secondary breakdown mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.