Motor drive circuit
US5793170A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 12, 1997 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Mar 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/085
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a motor drive circuit, the collector-emitter paths of two npn-type transistors are connected in series between a power line and ground, and the junction between the two transistors is connected to a motor coil. A control circuit feeds a control current to the base of the transistor connected to the power line so that this transistor supplies a drive current to the motor coil. A current mirror circuit is provided which is constituted of two pnp-type transistors whose emitters are connected to the power line, and the base and collector of the input-side transistor is connected to the control circuit through a diode. The base of another pnp-type transistor is connected to the cathode of the diode, and the emitter of this transistor is connected to the collector of the output-side transistor of the current mirror circuit and to the base of the transistor connected to the power line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.