Motor drive amplifier
AssigneeSony Corporation
InventorBarrett E. Guisinger
Life of this patent
Estimating the term…
Abstract
A motor drive circuit comprising a differential amplifier having inverting and non-inverting inputs and further having an output which is connected to the inputs of separate NPN and PNP, super-alpha configured amplifiers whose combined outputs are supplied to one lead of a motor. The other lead of the motor is connected through a resistor to the circuit ground. The voltage developed across this resistor is supplied to the inverting input of the differential amplifier such that the current through the motor will be equal to the input voltage supplied to the non-inverting input of the differential amplifier divided by the resistance of the resistor.
Claims10
In combination with a load, a drive amplifier circuit for driving the load in response to a drive input signal, the amplifier circuit comprising a circuit ground, a differential amplifier having an inverting input terminal, a non-inverting input terminal for receiving a drive input signal, and an output terminal, dual, super-alpha configured current amplifiers of opposite polarities, each having a separate input terminal and a separate output terminal, first resistance means connected in series with the load between the outputs of the super-alpha configured amplifiers and the circuit ground, means connecting the inverting input of the differential amplifier to a point in the series connection between the load and the first resistance means, and wherein the output of the differential amplifier is connected to the inputs of the super-alpha configured current amplifiers, whereby, when said drive input signal is applied to the non-inverting input of the differential amplifier, a current equal to the voltage magnitude of the drive input signal divided by said first resistance means will flow through the load.
An amplifier drive circuit for a load, the amplifier drive circuit comprising a circuit ground, a differential amplifier having a non-inverting input terminal, an inverting input terminal, and an output terminal, first and second NPN transistors, first and second PNP transistors, first and second resistance means, biassing means for supplying biassing voltages to the first and second NPN transistors and the first and second PNP transistors, and means for supplying an error signal to the non-inverting input of the differential amplifier, and wherein the output terminal of the differential amplifier is connected to the base terminals of the first NPN transistor and the second PNP transistor, the collector of first NPN transistor is connected to the base terminal of the first PNP transistor, the emitter of the first NPN transistor is connected to the collector of the first PNP transistor, to the input lead of the load, to the emitter of the second PNP transistor and to the collector of the second NPN transistor, and is also connected in series with the load and the second resistance means to the inverting input of the differential amplifier, the first resistance means is connected between the circuit ground and the junction of the load and the second resistance means, the collector of the second PNP transistor is connected to the base terminal of the second NPN transistor and the emitter of the second PNP transistor is connected to the base terminal of the second NPN transistor.
Dependencies are inferred from the claim text.