Powerless starting circuit
US4340851A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 18, 1980 |
| Grant date | Jul 20, 1982 |
| Priority date | — |
| Expiry date | Jun 18, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/901
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved start-up circuit is provided for self-biased circuits of the type connected to a supply voltage and having biasing currents stable at two operating points at which the biasing currents are either zero or nonzero in value when the supply voltage is nonzero and having sufficient regenerative feedback to raise the level of the biasing currents to the nonzero value when an initial current is provided to the circuit. The start-up circuit includes a resistive element which provides a current path from the supply voltage to the self-biased circuit and a transistor element, responsive to the current flow through the path for supplying an initial current to the self-biased circuit, whereupon the regenerative feedback causes the circuit to draw a current related to the biasing current through the current path as the biasing currents reach the nonzero operating point. The current flow through the path causes the transistor element to disconnect the initial current from the self-biased circuit as the nonzero operating point is reached. The start-up circuit draws no power from the voltage supply after the disconnection occurs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.